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Sample records for conformal radiation treatment

  1. A study of the radiobiological modeling of the conformal radiation therapy in cancer treatment

    Science.gov (United States)

    Pyakuryal, Anil Prasad

    Cancer is one of the leading causes of mortalities in the world. The precise diagnosis of the disease helps the patients to select the appropriate modality of the treatments such as surgery, chemotherapy and radiation therapy. The physics of X-radiation and the advanced imaging technologies such as positron emission tomography (PET) and computed tomography (CT) plays an important role in the efficient diagnosis and therapeutic treatments in cancer. However, the accuracy of the measurements of the metabolic target volumes (MTVs) in the PET/CT dual-imaging modality is always limited. Similarly the external beam radiation therapy (XRT) such as 3D conformal radiotherapy (3DCRT) and intensity modulated radiation therapy (IMRT) is the most common modality in the radiotherapy treatment. These treatments are simulated and evaluated using the XRT plans and the standard methodologies in the commercial planning system. However, the normal organs are always susceptible to the radiation toxicity in these treatments due to lack of knowledge of the appropriate radiobiological models to estimate the clinical outcomes. We explored several methodologies to estimate MTVs by reviewing various techniques of the target volume delineation using the static phantoms in the PET scans. The review suggests that the more precise and practical method of delineating PET MTV should be an intermediate volume between the volume coverage for the standardized uptake value (SUV; 2.5) of glucose and the 50% (40%) threshold of the maximum SUV for the smaller (larger) volume delineations in the radiotherapy applications. Similarly various types of optimal XRT plans were designed using the CT and PET/CT scans for the treatment of various types of cancer patients. The qualities of these plans were assessed using the universal plan-indices. The dose-volume criteria were also examined in the targets and organs by analyzing the conventional dose-volume histograms (DVHs). The biological models such as tumor

  2. Shaping and resizing of multifed slot radiators used in conformal microwave antenna arrays for hyperthermia treatment of large superficial diseases.

    Science.gov (United States)

    Maccarini, Paolo F; Arunachalam, Kavitha; Juang, Titania; De Luca, Valeria; Rangarao, Sneha; Neumann, Daniel; Martins, Carlos Daniel; Craciunescu, Oana; Stauffer, Paul R

    2009-01-01

    It has been recently shown that chestwall recurrence of breast cancer and many other superficial diseases can be successfully treated with the combination of radiation, chemotherapy and hyperthermia. Conformal microwave antenna array for hyperthermia treatment of large area superficial diseases can significantly increase patient comfort while at the same time facilitate treatment of larger and more irregularly shaped disease. A large number of small efficient antennas is preferable for improved control of heating, as the disease can be more accurately contoured and the lower power requirement correlates with system reliability, linearity and reduced cost. Thus, starting from the initially proposed square slot antennas, we investigated new designs for multi-fed slot antennas of several shapes that maximize slot perimeter while reducing radiating area, thus increasing antenna efficiency. Simulations were performed with commercial electromagnetic simulation software packages (Ansoft HFSS) to demonstrate that the antenna size reduction method is effective for several dual concentric conductor (DCC) aperture shapes and operating frequencies. The theoretical simulations allowed the development of a set of design rules for multi-fed DCC slot antennas that facilitate conformal heat treatments of irregular size and shape disease with large multi-element arrays. Independently on the shape, it is shown that the perimeter of 10cm at 915 MHz delivers optimal radiation pattern and efficiency. While the maximum radiation is obtained for a circular pattern the rectangular shape is the one that feels more efficiently the array space.

  3. Comparative study of four advanced 3d-conformal radiation therapy treatment planning techniques for head and neck cancer.

    Science.gov (United States)

    Herrassi, Mohamed Yassine; Bentayeb, Farida; Malisan, Maria Rosa

    2013-04-01

    For the head-and-neck cancer bilateral irradiation, intensity-modulated radiation therapy (IMRT) is the most reported technique as it enables both target dose coverage and organ-at-risk (OAR) sparing. However, during the last 20 years, three-dimensional conformal radiotherapy (3DCRT) techniques have been introduced, which are tailored to improve the classic shrinking field technique, as regards both planning target volume (PTV) dose conformality and sparing of OAR's, such as parotid glands and spinal cord. In this study, we tested experimentally in a sample of 13 patients, four of these advanced 3DCRT techniques, all using photon beams only and a unique isocentre, namely Bellinzona, Forward-Planned Multisegments (FPMS), ConPas, and field-in-field (FIF) techniques. Statistical analysis of the main dosimetric parameters of PTV and OAR's DVH's as well as of homogeneity and conformity indexes was carried out in order to compare the performance of each technique. The results show that the PTV dose coverage is adequate for all the techniques, with the FPMS techniques providing the highest value for D95%; on the other hand, the best sparing of parotid glands is achieved using the FIF and ConPas techniques, with a mean dose of 26 Gy to parotid glands for a PTV prescription dose of 54 Gy. After taking into account both PTV coverage and parotid sparing, the best global performance was achieved by the FIF technique with results comparable to that of IMRT plans. This technique can be proposed as a valid alternative when IMRT equipment is not available or patient is not suitable for IMRT treatment.

  4. Conformal orbit sparing radiation therapy: a treatment option for advanced skin cancer of the parotid and ear region

    OpenAIRE

    Foley, Heath; Hopley, Shane; Brown, Elizabeth; Bernard, Anne; Foote, Matthew

    2016-01-01

    Abstract Introduction New surgical methods have enabled resection of previously in‐operable tumours in the region of the parotid gland and ear. This has translated to deeper target volumes being treated with adjuvant radiotherapy. Due to the limitations of existing conformal techniques, alternative planning approaches are required to cover the target volume with appropriate sparing of adjacent critical structures. Although intensity modulated radiation therapy (IMRT) may be able to achieve th...

  5. Comparison of 3D conformal radiotherapy vs. intensity modulated radiation therapy (IMRT) of a stomach cancer treatment;Comparacion dosimetrica de radioterapia conformal 3D versus radioterapia de intensidad modulada (IMRT) de un tratamiento de cancer de estomago

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    Bernui de V, Maria Giselle; Cardenas, Augusto; Vargas, Carlos [Hospital Nacional Carlos Alberto Seguin Escobedo (ESSALUD), Arequipa (Peru). Servicio de Radioterapia

    2009-07-01

    The purpose of this work was to compare the dosimetry in 3D Conformal Radiotherapy with Intensity Modulated Radiation Therapy (IMRT) in a treatment of stomach cancer. For this comparison we selected a patient who underwent subtotal gastrectomy and D2 dissection for a T3N3 adenocarcinoma Mx ECIIIB receiving treatment under the scheme Quimio INT 0116 - in adjuvant radiotherapy. In the treatment plan was contouring the Clinical Target Volume (CTV) and the Planning Target Volume (PTV) was generated from the expansion of 1cm of the CTV, the risky organs contouring were: the liver, kidneys and spinal cord, according to the consensus definition of volumes in gastric cancer. The 3D Conformal Radiotherapy planning is carried out using 6 half beams following the Leong Trevol technique; for the IMRT plan was used 8 fields, the delivery technique is step-and-shoot. In both cases the fields were coplanar, isocentric and the energy used was 18 MV. Intensity Modulated Radiation Therapy (IMRT), in this case has proved to be a good treatment alternative to the technique of 3D Conformal Radiotherapy; the dose distributions with IMRT have better coverage of PTV and positions of the hot spots, as well as the kidneys volume that received higher doses to 2000 cGy is lower, but the decrease in dose to the kidneys is at the expense of increased dose in other organs like the liver. (author)

  6. Intensity modulated radiation therapy versus three-dimensional conformal radiation therapy for the treatment of high grade glioma: a dosimetric comparison.

    Science.gov (United States)

    MacDonald, Shannon M; Ahmad, Salahuddin; Kachris, Stefanos; Vogds, Betty J; DeRouen, Melissa; Gittleman, Alicia E; DeWyngaert, Keith; Vlachaki, Maria T

    2007-04-19

    The present study compared the dosimetry of intensity-modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3D-CRT) techniques in patients treated for high-grade glioma. A total of 20 patients underwent computed tomography treatment planning in conjunction with magnetic resonance imaging fusion. Prescription dose and normal-tissue constraints were identical for the 3D-CRT and IMRT plans. The prescribed dose was 59.4 Gy delivered at 1.8 Gy per fraction using 4-10 MV photons. Normal-tissue dose constraints were 50-54 Gy for the optic chiasm and nerves, and 55-60 Gy for the brainstem. The IMRT plan yielded superior target coverage as compared with the 3D-CRT plan. Specifically, minimum and mean planning target volume cone down doses were 54.52 Gy and 61.74 Gy for IMRT and 50.56 Gy and 60.06 Gy for 3D-CRT (p < or = 0.01). The IMRT plan reduced the percent volume of brainstem receiving a dose greater than 45 Gy by 31% (p = 0.004) and the percent volume of brain receiving a dose greater than 18 Gy, 24 Gy, and 45 Gy by 10% (p = 0.059), 14% (p = 0.015), and 40% (p < or = 0.0001) respectively. With IMRT, the percent volume of optic chiasm receiving more than 45 Gy was also reduced by 30.40% (p = 0.047). As compared with 3D-CRT, IMRT significantly increased the tumor control probability (p < or = 0.005) and lowered the normal-tissue complication probability for brain and brainstem (p < 0.033). Intensity-modulated radiation therapy improved target coverage and reduced radiation dose to the brain, brainstem, and optic chiasm. With the availability of new cancer imaging tools and more effective systemic agents, IMRT may be used to intensify tumor doses while minimizing toxicity, therefore potentially improving outcomes in patients with high-grade glioma.

  7. Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the hypofractionated treatment of high-risk prostate cancer

    Directory of Open Access Journals (Sweden)

    Yartsev Slav

    2008-01-01

    Full Text Available Abstract Background To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT with 3-dimensional conformal radiation therapy (3DCRT in the setting of hypofractionated high-risk prostate cancer treatment. Methods 3DCRT and dIMRT/Helical Tomotherapy(HT planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. Results When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p dose, 1–3 Gy over 5/10 dose points; p Conclusion dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies.

  8. Conformal pure radiation with parallel rays

    CERN Document Server

    Leistner, Thomas

    2011-01-01

    We define pure radiation metrics with parallel rays to be n-dimensional pseudo-Riemannian metrics that admit a parallel null line bundle K and whose Ricci tensor vanishes on vectors that are orthogonal to K. We give necessary conditions in terms of the Weyl, Cotton and Bach tensors for a pseudo-Riemannian metric to be conformal to a pure radiation metric with parallel rays. Then we derive conditions in terms of tractor calculus that are equivalent to the existence of a pure radiation metric with parallel rays in a conformal class. We also give an analogous result for n-dimensional pseudo-Riemannian pp-waves.

  9. Conformal Radiotherapy: Physics, Treatment Planning and Verification. Proceedings book

    Energy Technology Data Exchange (ETDEWEB)

    De Wagter, C. [ed.

    1995-12-01

    The goal of conformal radiotherapy is to establish radiation dose distributions that conform tightly to the target volume in view of limiting radiation to normal tissues. Conformal radiotherapy significantly improves both local control and palliation and thus contributes to increase survival and to improve the quality of life. The subjects covered by the symposium include : (1) conformal radiotherapy and multi-leaf collimation; (2) three dimensional imaging; (3) treatment simulation, planning and optimization; (4) quality assurance; and (5) dosimetry. The book of proceedings contains the abstracts of the invited lectures, papers and poster presentations as well as the full papers of these contributions.

  10. Radiation dosimetry of a conformal heat-brachytherapy applicator.

    Science.gov (United States)

    Taschereau, Richard; Stauffer, Paul R; Hsu, I-Chow; Schlorff, Jaime L; Milligan, Andrew J; Pouliot, Jean

    2004-08-01

    The purpose of this paper is to report the radiation dosimetric characteristics of a new combination applicator for delivering heat and radiation simultaneously to large area superficial disease conformal printed circuit board microwave antenna array (for heat generation), and a body-conforming 5-10 mm thick temperature-controlled water bolus. The rationale for applying both modalities simultaneously includes the potential for significantly higher response rate due to enhanced synergism of modalities, and lower peak toxicity due to temporal extension of heat and radiation induced toxicities. Treatment plans and radiation dosimetry are calculated with IPSA (an optimization tool developed at UCSF) for 15 x 15 cm(2) and 35 x 24 cm(2) applicators, lesion thicknesses of 5 to 15 mm, flat and curved surfaces, and catheter separation of 5 and 10 mm. The effect on skin dose of bolus thickness and presence of thin copper antenna structures between radiation source and tissue are also evaluated. Results demonstrate the ability of the applicator to provide conformal radiation dose coverage for up to 15 mm deep target volumes under the applicator. For clinically acceptable plans, tumor coverage is > 98%, homogeneity index > 0.95 and the percentage of normal tissue irradiated is antenna array is of the order 0.25% and secondary electron emissions are absorbed completely within 5 mm of water bolus and plastic layers. Both phenomena can then be neglected in dose calculations allowing commercial software to be used for treatment planning. This novel applicator should prove useful for the treatment of diffuse chestwall disease located over contoured anatomy that may be difficult to treat with single field external beam therapy. By delivering heat and radiation simultaneously, increased synergism is expected with a TER in the range of 2-5. Lowering radiation dose by an equivalent factor may produce lower radiation toxicity with similar efficacy, while preserving the option of

  11. Comparison of Radiation Treatment Plans for Breast Cancer between 3D Conformal in Prone and Supine Positions in Contrast to VMAT and IMRT Supine Positions

    Science.gov (United States)

    Bejarano Buele, Ana Isabel

    The treatment regimen for breast cancer patients typically involves Whole Breast Irradiation (WBI). The coverage and extent of the radiation treatment is dictated by location of tumor mass, breast tissue distribution, involvement of lymph nodes, and other factors. The current standard treatment approach used at our institution is a 3D tangential beam geometry, which involves two fields irradiating the breast, or a four field beam arrangement covering the whole breast and involved nodes, while decreasing the dose to organs as risk (OARs) such as the lung and heart. The coverage of these targets can be difficult to achieve in patients with unfavorable thoracic geometries, especially in those cases in which the planning target volume (PTV) is extended to the chest wall. It is a well-known fact that exposure of the heart to ionizing radiation has been proved to increase the subsequent rate of ischemic heart disease. In these cases, inverse planned treatments have become a proven alternative to the 3D approach. The goal of this research project is to evaluate the factors that affect our current techniques as well as to adapt the development of inverse modulated techniques for our clinic, in which breast cancer patients are one of the largest populations treated. For this purpose, a dosimetric comparison along with the evaluation of immobilization devices was necessary. Radiation treatment plans were designed and dosimetrically compared for 5 patients in both, supine and prone positions. For 8 patients, VMAT and IMRT plans were created and evaluated in the supine position. Skin flash incorporation for inverse modulated plans required measurement of the surface dose as well as an evaluation of breast volume changes during a treatment course. It was found that prone 3D conformal plans as well as the VMAT and IMRT plans are generally superior in sparing OARs to supine plans with comparable PTV coverage. Prone setup leads to larger shifts in breast volume as well as in

  12. A comprehensive dosimetric study of pancreatic cancer treatment using three-dimensional conformal radiation therapy (3DCRT), intensity-modulated radiation therapy (IMRT), volumetric-modulated radiation therapy (VMAT), and passive-scattering and modulated-scanning proton therapy (PT)

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    Ding, Xuanfeng; Dionisi, Francesco; Tang, Shikui; Ingram, Mark; Hung, Chun-Yu; Prionas, Evangelos; Lichtenwalner, Phil; Butterwick, Ian; Zhai, Huifang; Yin, Lingshu; Lin, Haibo; Kassaee, Alireza; Avery, Stephen, E-mail: stephen.avery@uphs.upenn.edu

    2014-07-01

    With traditional photon therapy to treat large postoperative pancreatic target volume, it often leads to poor tolerance of the therapy delivered and may contribute to interrupted treatment course. This study was performed to evaluate the potential advantage of using passive-scattering (PS) and modulated-scanning (MS) proton therapy (PT) to reduce normal tissue exposure in postoperative pancreatic cancer treatment. A total of 11 patients with postoperative pancreatic cancer who had been previously treated with PS PT in University of Pennsylvania Roberts Proton Therapy Center from 2010 to 2013 were identified. The clinical target volume (CTV) includes the pancreatic tumor bed as well as the adjacent high-risk nodal areas. Internal (iCTV) was generated from 4-dimensional (4D) computed tomography (CT), taking into account target motion from breathing cycle. Three-field and 4-field 3D conformal radiation therapy (3DCRT), 5-field intensity-modulated radiation therapy, 2-arc volumetric-modulated radiation therapy, and 2-field PS and MS PT were created on the patients’ average CT. All the plans delivered 50.4 Gy to the planning target volume (PTV). Overall, 98% of PTV was covered by 95% of the prescription dose and 99% of iCTV received 98% prescription dose. The results show that all the proton plans offer significant lower doses to the left kidney (mean and V{sub 18} {sub Gy}), stomach (mean and V{sub 20} {sub Gy}), and cord (maximum dose) compared with all the photon plans, except 3-field 3DCRT in cord maximum dose. In addition, MS PT also provides lower doses to the right kidney (mean and V{sub 18} {sub Gy}), liver (mean dose), total bowel (V{sub 20} {sub Gy} and mean dose), and small bowel (V{sub 15} {sub Gy} absolute volume ratio) compared with all the photon plans and PS PT. The dosimetric advantage of PT points to the possibility of treating tumor bed and comprehensive nodal areas while providing a more tolerable treatment course that could be used for dose

  13. Treatment-Related Morbidity in Prostate Cancer: A Comparison of 3-Dimensional Conformal Radiation Therapy With and Without Image Guidance Using Implanted Fiducial Markers

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    Singh, Jasmeet, E-mail: drsingh.j@gmail.com [Calvary Mater Newcastle, Newcastle (Australia); Greer, Peter B. [School of Physical and Mathematical Sciences, University of Newcastle, Newcastle (Australia); White, Martin A. [School of Medicine and Public Health, University of Newcastle, Newcastle (Australia); Parker, Joel; Patterson, Jackie [Calvary Mater Newcastle, Newcastle (Australia); Tang, Colin I.; Capp, Anne; Wratten, Christopher; Denham, James W. [Calvary Mater Newcastle, Newcastle (Australia); School of Medicine and Public Health, University of Newcastle, Newcastle (Australia)

    2013-03-15

    Purpose: To estimate the prevalence of rectal and urinary dysfunctional symptoms using image guided radiation therapy (IGRT) with fiducials and magnetic resonance planning for prostate cancer. Methods and Materials: During the implementation stages of IGRT between September 2008 and March 2010, 367 consecutive patients were treated with prostatic irradiation using 3-dimensional conformal radiation therapy with and without IGRT (non-IGRT). In November 2010, these men were asked to report their bowel and bladder symptoms using a postal questionnaire. The proportions of patients with moderate to severe symptoms in these groups were compared using logistic regression models adjusted for tumor and treatment characteristic variables. Results: Of the 282 respondents, the 154 selected for IGRT had higher stage tumors, received higher prescribed doses, and had larger volumes of rectum receiving high dosage than did the 128 selected for non-IGRT. The follow-up duration was 8 to 26 months. Compared with the non-IGRT group, improvement was noted in all dysfunctional rectal symptoms using IGRT. In multivariable analyses, IGRT improved rectal pain (odds ratio [OR] 0.07 [0.009-0.7], P=.02), urgency (OR 0.27 [0.11-0.63], P=<.01), diarrhea (OR 0.009 [0.02-0.35], P<.01), and change in bowel habits (OR 0.18 [0.06-0.52], P<.010). No correlation was observed between rectal symptom levels and dose-volume histogram data. Urinary dysfunctional symptoms were similar in both treatment groups. Conclusions: In comparison with men selected for non-IGRT, a significant reduction of bowel dysfunctional symptoms was confirmed in men selected for IGRT, even though they had larger volumes of rectum treated to higher doses.

  14. Dosimetric comparison study between intensity modulated radiation therapy and three-dimensional conformal proton therapy for pelvic bone marrow sparing in the treatment of cervical cancer.

    Science.gov (United States)

    Song, William Y; Huh, Soon N; Liang, Yun; White, Greg; Nichols, R Charles; Watkins, W Tyler; Mundt, Arno J; Mell, Loren K

    2010-08-15

    The objective was to compare intensity-modulated radiation therapy (IMRT) with 3D conformal proton therapy (3DCPT) in the treatment of cervical cancer. In particular, each technique's ability to spare pelvic bone marrow (PBM) was of primary interest in this study. A total of six cervical cancer patients (3 postoperative and 3 intact) were planned and analyzed. All plans had uniform 1.0 cm CTV-PTV margin and satisfied the 95% PTV with 100% isodose (prescription dose = 45 Gy) coverage. Dose-volume histograms (DVH) were analyzed for comparison. The overall PTV and PBM volumes were 1035.9 ± 192.2 cc and 1151.4 ± 198.3 cc, respectively. In terms of PTV dose conformity index (DCI) and dose homogeneity index (DHI), 3DCPT was slightly superior to IMRT with 1.00 ± 0.001, 1.01 ± 0.02, and 1.10 ± 0.02, 1.13 ± 0.01, respectively. In addition, 3DCPT demonstrated superiority in reducing lower doses (i.e., V30 or less) to PBM, small bowel and bladder. Particularly in PBM, average V10 and V20 reductions of 10.8% and 7.4% (p = 0.001 and 0.04), respectively, were observed. However, in the higher dose range, IMRT provided better sparing (> V30). For example, in small bowel and PBM, average reductions in V45 of 4.9% and 10.0% (p = 0.048 and 0.008), respectively, were observed. Due to its physical characteristics such as low entrance dose, spread-out Bragg peak and finite particle range of protons, 3DCPT illustrated superior target coverage uniformity and sparing of the lower doses in PBM and other organs. Further studies are, however, needed to fully exploit the benefits of protons for general use in cervical cancer.

  15. Radiation Analysis and Characteristics of Conformal Reflectarray Antennas

    Directory of Open Access Journals (Sweden)

    Payam Nayeri

    2012-01-01

    Full Text Available This paper investigates the feasibility of designing reflectarray antennas on conformal surfaces. A generalized analysis approach is presented that can be applied to compute the radiation performance of conformal reflectarray antennas. Using this approach, radiation characteristics of conformal reflectarray antennas on singly curved platforms are studied and the performances of these designs are compared with planar designs. It is demonstrated that a conformal reflectarray antenna can be a suitable choice for applications requiring high-gain antennas on curved platforms.

  16. Treatment techniques for 3D conformal radiation to breast and chest wall including the internal mammary chain.

    Science.gov (United States)

    Sonnik, Deborah; Selvaraj, Raj N; Faul, Clare; Gerszten, Kristina; Heron, Dwight E; King, Gwendolyn C

    2007-01-01

    Breast, chest wall, and regional nodal irradiation have been associated with an improved outcome in high-risk breast cancer patients. Complex treatment planning is often utilized to ensure complete coverage of the target volume while minimizing the dose to surrounding normal tissues. The 2 techniques evaluated in this report are the partially wide tangent fields (PWTFs) and the 4-field photon/electron combination (the modified "Kuske Technique"). These 2 techniques were evaluated in 10 consecutive breast cancer patients. All patients had computerized tomographic (CT) scans for 3D planning supine on a breast board. The breast was defined clinically by the physician and confirmed radiographically with radiopaque bebes. The resulting dose-volume histograms (DVHs) of normal and target tissues were then compared. The deep tangent field with blocks resulted in optimal coverage of the target and the upper internal mammary chain (IMC) while sparing of critical and nontarget tissues. The wide tangent technique required less treatment planning and delivery time. We compared the 2 techniques and their resultant DVHs and feasibility in a busy clinic.

  17. Advances in three-dimensional conformal radiation therapy physics with intensity modulation.

    Science.gov (United States)

    Webb, S

    2000-09-01

    Intensity-modulated radiation therapy, a specific form of conformal radiation therapy, is currently attracting a lot of attention, and there are high expectations for this class of treatment techniques. Several new technologies are in development, but physicists are still working to improve the physical basis of radiation therapy.

  18. Prostate and seminal vesicle volume based consideration of prostate cancer patients for treatment with 3D-conformal or intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Nandanuri M. S.; Nori, Dattatreyudu; Chang, Hyesook; Lange, Christopher S.; Ravi, Akkamma [Department of Radiation Oncology, New York Hospital Queens, Flushing, New York 11355 (United States); Department of Radiation Oncology, State University of New York Downstate Medical Center, Brooklyn, New York 11203 (United States); Department of Radiation Oncology, New York Hospital Queens, Flushing, New York 11355 (United States)

    2010-07-15

    Purpose: The purpose of this article was to determine the suitability of the prostate and seminal vesicle volumes as factors to consider patients for treatment with image-guided 3D-conformal radiation therapy (3D-CRT) or intensity-modulated radiation therapy (IMRT), using common dosimetry parameters as comparison tools. Methods: Dosimetry of 3D and IMRT plans for 48 patients was compared. Volumes of prostate, SV, rectum, and bladder, and prescriptions were the same for both plans. For both 3D and IMRT plans, expansion margins to prostate+SV (CTV) and prostate were 0.5 cm posterior and superior and 1 cm in other dimensions to create PTV and CDPTV, respectively. Six-field 3D plans were prepared retrospectively. For 3D plans, an additional 0.5 cm margin was added to PTV and CDPTV. Prescription for both 3D and IMRT plans was the same: 45 Gy to CTV followed by a 36 Gy boost to prostate. Dosimetry parameters common to 3D and IMRT plans were used for comparison: Mean doses to prostate, CDPTV, SV, rectum, bladder, and femurs; percent volume of rectum and bladder receiving 30 (V30), 50 (V50), and 70 Gy (V70), dose to 30% of rectum and bladder, minimum and maximum point dose to CDPTV, and prescription dose covering 95% of CDPTV (D95). Results: When the data for all patients were combined, mean dose to prostate and CDPTV was higher with 3D than IMRT plans (P<0.01). Mean D95 to CDPTV was the same for 3D and IMRT plans (P>0.2). On average, among all cases, the minimum point dose was less for 3D-CRT plans and the maximum point dose was greater for 3D-CRT than for IMRT (P<0.01). Mean dose to 30% rectum with 3D and IMRT plans was comparable (P>0.1). V30 was less (P<0.01), V50 was the same (P>0.2), and V70 was more (P<0.01) for rectum with 3D than IMRT plans. Mean dose to bladder was less with 3D than IMRT plans (P<0.01). V30 for bladder with 3D plans was less than that of IMRT plans (P<0.01). V50 and V70 for 3D plans were the same for 3D and IMRT plans (P>0.2). Mean dose to femurs

  19. Carcinoma of the anal canal: Intensity modulated radiation therapy (IMRT) versus three-dimensional conformal radiation therapy (3DCRT)

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    Sale, Charlotte; Moloney, Phillip; Mathlum, Maitham [Andrew Love Cancer Centre, Geelong Hospital, Geelong, Victoria (Australia)

    2013-12-15

    Patients with anal canal carcinoma treated with standard conformal radiotherapy frequently experience severe acute and late toxicity reactions to the treatment area. Roohipour et al. (Dis Colon Rectum 2008; 51: 147–53) stated a patient's tolerance of chemoradiation to be an important prediction of treatment success. A new intensity modulated radiation therapy (IMRT) technique for anal carcinoma cases has been developed at the Andrew Love Cancer Centre aimed at reducing radiation to surrounding healthy tissue. A same-subject repeated measures design was used for this study, where five anal carcinoma cases at the Andrew Love Cancer Centre were selected. Conformal and IMRT plans were generated and dosimetric evaluations were performed. Each plan was prescribed a total of 54 Gray (Gy) over a course of 30 fractions to the primary site. The IMRT plans resulted in improved dosimetry to the planning target volume (PTV) and reduction in radiation to the critical structures (bladder, external genitalia and femoral heads). Statistically there was no difference between the IMRT and conformal plans in the dose to the small and large bowel; however, the bowel IMRT dose–volume histogram (DVH) doses were consistently lower. The IMRT plans were superior to the conformal plans with improved dose conformity and reduced radiation to the surrounding healthy tissue. Anecdotally it was found that patients tolerated the IMRT treatment better than the three-dimensional (3D) conformal radiation therapy. This study describes and compares the planning techniques.

  20. A dosimetric comparison between 3D-Conformal radiation therapy and intensity modulated radiation therapy plans in the treatment of posterior fossa boost in children with high risk medulloblastom

    Institute of Scientific and Technical Information of China (English)

    Saad El Din I; Abd El AAl H; Makaar W; Mashhour K; El Beih D; Hashem W

    2013-01-01

    Objective:The work is a comparative study between two modalities of radiation therapy, the aim of which is to compare 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) in treating posterior fossa boost in children with high risk medul oblastoma;dosimetrical y evaluating and comparing both techniques as regard target coverage and doses to organs at risk (OAR). Methods:Twenty patients with high risk medul oblastoma were treated by 3D-CRT technique. A dosimetric comparison was done by performing two plans for the posterior fossa boost, 3D-CRT and IMRT plans, for the same patient using Eclipse planning system (version 8.6). Results:IMRT had a better conformity index compared to 3D-CRT plans (P value of 0.000). As for the dose homogeneity it was also better in the IMRT plans, yet it hasn’t reached the statistical significant value. Also, doses received by the cochleae, brainstem and spinal cord were significantly less in the IMRT plans than those of 3D-CRT (P value<0.05). Conclusion:IMRT technique was clearly able to improve conformity and homogeneity index, spare the cochleae, reduce dose to the brainstem and spinal cord in comparison to 3D-CRT technique.

  1. Engineering antenna radiation patterns via quasi-conformal mappings.

    Science.gov (United States)

    García-Meca, Carlos; Martínez, Alejandro; Leonhardt, Ulf

    2011-11-21

    We use a combination of conformal and quasi-conformal mappings to engineer isotropic electromagnetic devices that modify the omnidirectional radiation pattern of a point source. For TE waves, the designed devices are also non-magnetic. The flexibility offered by the proposed method is much higher than that achieved with conformal mappings. As a result, it is shown that complex radiation patterns can be achieved, which can combine high directivity in a desired number of arbitrary directions and isotropic radiation in other specified angular ranges. In addition, this technique enables us to control the power radiated in each direction to a certain extent. The obtained results are valid for any part of the spectrum. The potential of this method is illustrated with some examples. Finally, we study the frequency dependence of the considered devices and propose a practical dielectric implementation.

  2. Phantom dosimetry at 15 MV conformal radiation therapy

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    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Luxemburgo Hospital, Mario Penna Institute, Belo Horizonte, MG (Brazil)

    2015-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  3. Phantom dosimetry at 15 MV conformal radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Thompson, Larissa; Campos, Tarcisio P.R., E-mail: larissathompson@hotmail.com, E-mail: tprcampos@yahoo.com.br [Universidade Federal de Minas Gerais (UFMG), Minas Gerais, MG (Brazil). Dept. de Engenharia Nuclear; Dias, Humberto G., E-mail: fisicamedica.hl@mariopenna.org.br [Instituto Mario Penna, Minas Gerais, MG (Brazil). Hospital Luxemburgo

    2013-07-01

    The main goal of this work was to evaluate the spatial dose distribution into a tumor simulator inside a head phantom exposed to a 15MV 3D conformal radiation therapy in order to validate internal doses. A head and neck phantom developed by the Ionizing Radiation Research Group (NRI) was used on the experiments. Therapy Radiation planning (TPS) was performed based on those CT images, satisfying a 200 cGy prescribed dose split in three irradiation fields. The TPS assumed 97% of prescribed dose cover the prescribed treatment volume (PTV). Radiochromic films in a solid water phantom provided dose response as a function of optical density. Spatial dosimetric distribution was generated by radiochromic film samples inserted into tumor simulator and brain. The spatial dose profiles held 70 to 120% of the prescribed dose. In spite of the stratified profile, as opposed to the smooth dose profile from TPS, the tumor internal doses were within a 5% deviation from 214.4 cGy evaluated by TPS. 83.2% of the points with a gamma value of less than 1 (3%/3mm) for TPS and experimental values, respectively. At the tumor, a few dark spots in the film caused the appearance of outlier points in 13-15% of dose deviation percentage. As final conclusion, such dosimeter choice and the physical anthropomorphic and anthropometric phantom provided an efficient method for validating radiotherapy protocols. (author)

  4. A dosimetric evaluation of volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy for the lower extremity soft tissue sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sol Min; Song, Seong Chan; Hyun, Sung Eun; Park, Heung Deuk; Lee, Jaegi; Kim, Young Suk; Kim, Gwi Eon [Dept. of Radiation Oncology, Jeju National University Hospital, Jeju (Korea, Republic of)

    2016-06-15

    A dosimetric evaluation of volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy for the lower extremity soft tissue sarcoma For the lower extremity soft tissue sarcoma, volumetric modulated arc therapy, intensity modulated radiation therapy, and three-dimensional conformal radiation therapy were evaluated to compare these three treatment planning technique. The mean doses to the planning target volume and the femur were calculated to evaluate target coverage and the risk of bone fracture during radiation therapy. Volumetric modulated arc therapy can reduce the dose to the femur without compromising target coverage and reduce the treatment time compared with intensity modulated radiation therapy.

  5. Three dimensional conformal radiation therapy may improve the therapeutic ratio of radiation therapy after pneumonectomy for lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Trouette, R.; Causse, N.; Elkhadri, M.; Caudry, M.; Maire, J.P.; Houlard, J.P.; Racaldini, L.; Demeaux, H.

    1995-12-01

    Three dimensional conformal radiation therapy would allow to decrease the normal tissue dose while maintaining the same target dose as standard treatment. To evaluate the feasibility of normal tissue dose reduction for ten patients with pneumonectomy for lung cancer, we determined the dose distribution to the normal tissue with 3-dimensional conformal radiation therapy (3-DCRT) and conventional treatment planning (CTP). Dose-volume histograms for target and normal tissue (lung, heart) were used for comparison of the different treatment planning. The mean percentages of lung and heart volumes which received 40 Gy with 3-DCRT were respectively 63% and 37% of the mean percentage of lung and volumes which received the same dose with CTP. These preliminary results suggest that conformal therapy may improve the therapeutic ratio by reducing risk to normal tissue.

  6. Radiative breaking of conformal symmetry in the Standard Model

    Science.gov (United States)

    Arbuzov, A. B.; Nazmitdinov, R. G.; Pavlov, A. E.; Pervushin, V. N.; Zakharov, A. F.

    2016-02-01

    Radiative mechanism of conformal symmetry breaking in a comformal-invariant version of the Standard Model is considered. The Coleman-Weinberg mechanism of dimensional transmutation in this system gives rise to finite vacuum expectation values and, consequently, masses of scalar and spinor fields. A natural bootstrap between the energy scales of the top quark and Higgs boson is suggested.

  7. Integration using invariant operators Conformally flat radiation metrics

    CERN Document Server

    Edgar, S B

    1999-01-01

    A new method is presented for obtaining the general conformally flat radiation metric by using the differential operators of Machado Ramos and Vickers (a generalisation of the GHP operators) which are invariant under null rotations and spin and boosts. The solution is found by constructing involutive tables of these derivatives applied to the quantities which arise in the Karlhede classification of metrics.

  8. Conformal proton radiation therapy for pediatric low-grade astrocytomas

    Energy Technology Data Exchange (ETDEWEB)

    Hug, E.B. [Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Radiation Medicine; Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Pediatrics and Dept. of Pathology; Darthmouth-Hitchcock Medical Center, Lebanon, New Hampshire (United States). Section of Radiation Oncology; Muenter, M.W.; Archambeau, J.O.; DeVries, A.; Loredo, L.N.; Grove, R.I.; Slater, J.D. [Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Radiation Medicine; Liwnicz, B. [Loma Linda Univ. Medical Center, Loma Linda, CA (United States). Dept. of Pathology

    2002-01-01

    Background: To evaluate the safety and efficacy of proton radiation therapy (PRT) for intracranial low-grade astrocytomas, the authors analyzed the first 27 pediatric patients treated at Loma Linda University Medical Center (LLUMC). Patients and Method: Between September 1991 and August 1997, 27 patients (13 female, 14 male) underwent fractionated proton radiation therapy for progressive or recurrent low-grade astrocytoma. Age at time of treatment ranged from 2 to 18 years (mean: 8.7 years). Tumors were located centrally (diencephatic) in 15 patients, in the cerebral and cerebellar hemispheres in seven patients, and in the brainstem in five patients. 25/27 patients (92%) were treated for progressive, unresectable, or residual disease following subtotal resection. Tissue diagnosis was available in 23/27 patients (85%). Four patients with optic pathway tumors were treated without histologic confirmation. Target doses between 50.4 and 63.0 CGE (cobalt gray equivalent, mean: 55.2 CGE) were prescribed at 1.8 CGE per fraction, five treatments per week. Results: At a mean follow-up period of 3.3 years (0.6-6.8 years), 6/27 patients experienced local failure (all located within the irradiated field), and 4/27 patients had died. By anatomic site these data translated into rates of local control and survival of 87% (13/15 patients) and 93% (14/15 patients) for central tumors, 71% (5/7 patients) and 86% (6/7 patients) for hemispheric tumors, and 60% (3/5 patients) and 60% (3/5 patients) for tumors located in the brainstem. Proton radiation therapy was generally well tolerated. All children with local control maintained their performance status. One child with associated neurofibromatosis, Type 1, developed Moyamoya disease. All six patients with optic pathway tumors and useful vision maintained or improved their visual status. Conclusions: This report on pediatric low-grade astrocytomas confirms proton radiation therapy as a safe and efficacious 3-D conformal treatment

  9. Synchrotron radiation in strongly coupled conformal field theories

    CERN Document Server

    Athanasiou, Christiana; Liu, Hong; Nickel, Dominik; Rajagopal, Krishna

    2010-01-01

    Using gauge/gravity duality, we compute the energy density and angular distribution of the power radiated by a quark undergoing circular motion in strongly coupled ${\\cal N}=4$ supersymmetric Yang-Mills (SYM) theory. We compare the strong coupling results to those at weak coupling, finding them to be very similar. In both regimes, the angular distribution of the radiated power is in fact similar to that of synchrotron radiation produced by an electron in circular motion in classical electrodynamics: the quark emits radiation in a narrow beam along its velocity vector with a characteristic opening angle $\\alpha \\sim 1/\\gamma$. To an observer far away from the quark, the emitted radiation appears as a short periodic burst, just like the light from a lighthouse does to a ship at sea. Our strong coupling results are valid for any strongly coupled conformal field theory with a dual classical gravity description.

  10. Dosimetric Comparison of Volumetric Modulated Arc Therapy, Static Field Intensity Modulated Radiation Therapy, and 3D Conformal Planning for the Treatment of a Right-Sided Reconstructed Chest Wall and Regional Nodal Case

    Directory of Open Access Journals (Sweden)

    Vishruta A. Dumane

    2014-01-01

    Full Text Available We compared 3D conformal planning, static field intensity modulated radiation therapy (IMRT, and volumetric modulated arc therapy (VMAT to investigate the suitable treatment plan and delivery method for a right-sided reconstructed chest wall and nodal case. The dose prescribed for the reconstructed chest wall and regional nodes was 50.4 Gy. Plans were compared for target coverage and doses of the lungs, heart, contralateral breast, and healthy tissue. All plans achieved acceptable coverage of the target and IMNs. The best right lung sparing achieved with 3D was a V20 Gy of 31.09%. Compared to it, VMAT reduced the same by 10.85% and improved the CI and HI over 3D by 18.75% and 2%, respectively. The ipsilateral lung V5 Gy to V20 Gy decreased with VMAT over IMRT by as high as 17.1%. The contralateral lung V5 Gy was also lowered with VMAT compared to IMRT by 16.22%. The MU and treatment beams were lowered with VMAT over IMRT by 30% and 10, respectively, decreasing the treatment time by >50%. VMAT was the treatment plan and delivery method of choice for this case due to a combination of improved lung sparing and reduced treatment time without compromising target coverage.

  11. Conformation change of enzyme molecules in laser radiation field

    Science.gov (United States)

    Leshenyuk, N. S.; Prigun, M. V.; Apanasevitsh, E. E.; Kruglik, G. S.

    2007-06-01

    As a result of an analysis of macromolecules properties in the coherent optical radiation field and with allowance for the experimentally obtained unique data on the interaction of lazer radiation with biomolecules (dependence of the interaction efficiency on the coherence length, presence of the effect in the spectra region far from the absorption band), a mechanism of wave interaction is developed. Using this mathematical model, the calculations of a change in the macromolecules oscillatory energy in the coherent radiation field are performed. It is shown that the increase of macromolecules oscillatory energy depends strongly on the coherence length of radiation. On exposure to noncoherent radiation, the biomolecules oscillatory energy practically does not change, whereas on exposure to laser radiation (coherence length ~3 cm), energy of oscillations of atoms increases by an order of 2÷4, which results in a change in the conformation of biomolecules and activity of enzymes. Recently a lot of data are received concerning the change of lysosomal enzymes activity in blood plasma under action of laser radiation.

  12. Radiatively induced breaking of conformal symmetry in a superpotential

    Science.gov (United States)

    Arbuzov, A. B.; Cirilo-Lombardo, D. J.

    2016-07-01

    Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman-Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.

  13. Radiatively Induced Breaking of Conformal Symmetry in a Superpotential

    CERN Document Server

    Arbuzov, A B

    2015-01-01

    Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman-Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.

  14. Radiatively induced breaking of conformal symmetry in a superpotential

    Energy Technology Data Exchange (ETDEWEB)

    Arbuzov, A.B. [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); Department of Higher Mathematics, Dubna State University, 141982 Dubna (Russian Federation); Cirilo-Lombardo, D.J., E-mail: diego777jcl@gmail.com [Bogoliubov Laboratory of Theoretical Physics, Joint Institute for Nuclear Research, 141980 Dubna (Russian Federation); National Institute of Plasma Physics (INFIP-CONICET), Department of Physics, FCEyN, Universidad de Buenos Aires, Buenos Aires 1428 (Argentina)

    2016-07-10

    Radiatively induced symmetry breaking is considered for a toy model with one scalar and one fermion field unified in a superfield. It is shown that the classical quartic self-interaction of the superfield possesses a quantum infrared singularity. Application of the Coleman–Weinberg mechanism for effective potential leads to the appearance of condensates and masses for both scalar and fermion components. That induces a spontaneous breaking of the initial classical symmetries: the supersymmetry and the conformal one. The energy scales for the scalar and fermion condensates appear to be of the same order, while the renormalization scale is many orders of magnitude higher. A possibility to relate the considered toy model to conformal symmetry breaking in the Standard Model is discussed.

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

    Energy Technology Data Exchange (ETDEWEB)

    Vogelius, Ivan S.; Westerly, David C.; Cannon, George M.; Bentzen, Soeren M. (Dept. of Human Oncology, Univ. of Wisconsin School of Medicine and Public Health, Madison, WI (United States)), E-mail: bentzen@humonc.wisc.edu

    2010-10-15

    Purpose. 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. Material and methods. Eighteen non-small cell lung cancer patients previously treated with helical tomotherapy were selected. For each patient a 3D-conformal plan (3D-CRT) plan was produced in addition to the delivered plan. The standard fractionation schedule was set to 60 Gy in 30 fractions. Iso-efficacy comparisons with hypofractionation were performed by changing the fractionation and the physical prescription dose while keeping the equivalent tumor dose in 2 Gy fractions constant. The risk of developing RP after radiotherapy was estimated using the Mean Equivalent Lung Dose in 2-Gy fractions (MELD2) NTCP model with alpha/beta=4 Gy for the residual lung. Overall treatment time was kept constant. Results. The mean risk of clinical RP after standard fractionation was 7.6% for Tomotherapy (range: 2.8-15.9%) and 9.2% for 3D-CRT (range 3.2-20.2%). Changing to 20 fractions, the Tomotherapy plans became slightly less toxic if the tumor alpha/beta ratio, (alpha/beta)T, was 7 Gy (mean RP risk 7.5%, range 2.8-16%) while the 3D-CRT plans became marginally more toxic (mean RP risk 9.8%, range 3.2-21%). If (alpha/beta)T was 13 Gy, the mean estimated risk of RP is 7.9% for Tomotherapy (range: 2.8-17%) and 10% for 3D-CRT (range 3.2-22%). Conclusion. Modern highly conformal dose distributions are radiobiologically more forgiving with respect to hypofractionation, even for a normal tissue endpoint where alpha/beta is lower than for the tumor in question.

  16. Classically conformal radiative neutrino model with gauged B - L symmetry

    Science.gov (United States)

    Okada, Hiroshi; Orikasa, Yuta

    2016-09-01

    We propose a classically conformal model in a minimal radiative seesaw, in which we employ a gauged B - L symmetry in the standard model that is essential in order to work the Coleman-Weinberg mechanism well that induces the B - L symmetry breaking. As a result, nonzero Majorana mass term and electroweak symmetry breaking simultaneously occur. In this framework, we show a benchmark point to satisfy several theoretical and experimental constraints. Here theoretical constraints represent inert conditions and Coleman-Weinberg condition. Experimental bounds come from lepton flavor violations (especially μ → eγ), the current bound on the Z‧ mass at the CERN Large Hadron Collider, and neutrino oscillations.

  17. Radiation Therapy: Additional Treatment Options

    Science.gov (United States)

    ... Cancer Upper GI Cancers Search x FIND A RADIATION ONCOLOGIST CLOSE SNIPEND TREATMENT TYPES SNIPSTART Home / Treatment ... novel targeted therapies can act as radiosensitizers. Systemic Radiation Therapy Certain cancers may be treated with radioactive ...

  18. Lie symmetries for a conformally flat radiating star

    CERN Document Server

    Abebe, G; Maharaj, S D

    2014-01-01

    We consider a relativistic radiating spherical star in conformally flat spacetimes. In particular we study the junction condition relating the radial pressure to the heat flux at the boundary of the star which is a nonlinear partial differential equation. The Lie symmetry generators that leave the equation invariant are identified and we generate an optimal system. Each element of the optimal system is used to reduce the partial differential equation to an ordinary differential equation which is further analysed. We identify new categories of exact solutions to the boundary conditions. Two classes of solutions are of interest. The first class depends on a self similar variable. The second class is separable in the spacetime variables.

  19. Comparative skin dose measurement in the treatment of anal canal cancer: conventional versus conformal therapy.

    Science.gov (United States)

    Devic, Slobodan; Hegyi, Gyorgy; Vuong, Té; Muanza, Thierry; Podgorsak, Ervin B

    2004-06-01

    The subject of this work was to compare the effect of Conventional and Conformal techniques, used for anal canal cancer treatments, on the skin dose deposition. Skin dose was measured on a Rando phantom using XR-T GAFCHROMIC film. A skin surface dose histogram was constructed and a skin dose profile in the sagittal direction of the perineal region was measured, for both techniques. The measured skin dose in the anterior and posterior region of the skin exposed to radiation is from two to ten times higher when using a conventional technique. In the perineal region, an 85% of the prescription isodose line spreads over 25% of the perineum for conformal technique as compared to 65% with conventional techniques. In addition, conformal technique dose profiles confine better the anatomical position of the anal verge than conventional techniques. Results presented in this work confirm clinically observed improvement in the radiation-induced dermatitis when using the conformal technique.

  20. Methodologies in the modeling of combined chemo-radiation treatments

    Science.gov (United States)

    Grassberger, C.; Paganetti, H.

    2016-11-01

    The variety of treatment options for cancer patients has increased significantly in recent years. Not only do we combine radiation with surgery and chemotherapy, new therapeutic approaches such as immunotherapy and targeted therapies are starting to play a bigger role. Physics has made significant contributions to radiation therapy treatment planning and delivery. In particular, treatment plan optimization using inverse planning techniques has improved dose conformity considerably. Furthermore, medical physics is often the driving force behind tumor control and normal tissue complication modeling. While treatment optimization and outcome modeling does focus mainly on the effects of radiation, treatment modalities such as chemotherapy are treated independently or are even neglected entirely. This review summarizes the published efforts to model combined modality treatments combining radiation and chemotherapy. These models will play an increasing role in optimizing cancer therapy not only from a radiation and drug dosage standpoint, but also in terms of spatial and temporal optimization of treatment schedules.

  1. A 5-year investigation of children's adaptive functioning following conformal radiation therapy for localized ependymoma.

    Science.gov (United States)

    Netson, Kelli L; Conklin, Heather M; Wu, Shengjie; Xiong, Xiaoping; Merchant, Thomas E

    2012-09-01

    Conformal and intensity modulated radiation therapies have the potential to preserve cognitive outcomes in children with ependymoma; however, functional behavior remains uninvestigated. This longitudinal investigation prospectively examined intelligence quotient (IQ) and adaptive functioning during the first 5 years after irradiation in children diagnosed with ependymoma. The study cohort consisted of 123 children with intracranial ependymoma. Mean age at irradiation was 4.60 years (95% confidence interval [CI], 3.85-5.35). Serial neurocognitive evaluations, including an age-appropriate IQ measure and the Vineland Adaptive Behavior Scales (VABS), were completed before irradiation, 6 months after treatment, and annually for 5 years. A total of 579 neurocognitive evaluations were included in these analyses. Baseline IQ and VABS were below normative means (PVABS across the follow-up period, except for the VABS Communication Index, which declined significantly (P=.015). Annual change in IQ (-.04 points) did not correlate with annual change in VABS (-.90 to +.44 points). Clinical factors associated with poorer baseline performance (P<.05) included preirradiation chemotherapy, cerebrospinal fluid shunt placement, number and extent of surgical resections, and younger age at treatment. No clinical factors significantly affected the rate of change in scores. Conformal and intensity modulated radiation therapies provided relative sparing of functional outcomes including IQ and adaptive behaviors, even in very young children. Communication skills remained vulnerable and should be the target of preventive and rehabilitative interventions. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Volume visualization in radiation treatment planning.

    Science.gov (United States)

    Pelizzari, C A; Chen, G T

    2000-12-01

    Radiation treatment planning (RTP), historically an image-intensive discipline and one of the first areas in which 3D information from imaging was clinically applied, has become even more critically dependent on accurate 3D definition of target and non-target structures in recent years with the advent of conformal radiation therapy. In addition to the interactive display of wireframe or shaded surface models of anatomic objects, proposed radiation beams, beam modifying devices, and calculated dose distributions, recently significant use has been made of direct visualization of relevant anatomy from image data. Dedicated systems are commercially available for the purpose of geometrically optimizing beam placement, implementing in virtual reality the functionality of standard radiation therapy simulators. Such "CT simulation" systems rely heavily on 3D visualization and on reprojection of image data to produce simulated radiographs for comparison with either diagnostic-quality radiographs made on a simulator or megavoltage images made using the therapeutic beams themselves. Although calculation and analysis of dose distributions is an important component of radiation treatment design, geometric targeting with optimization based on 3D anatomic information is frequently performed as a separate step independent of dose calculations.

  3. Bolus electron conformal therapy for the treatment of recurrent inflammatory breast cancer: a case report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Michelle M., E-mail: mmkim@mdanderson.org [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Kudchadker, Rajat J.; Kanke, James E.; Zhang, Sean; Perkins, George H. [Department of Radiation Oncology, University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

    2012-07-01

    The treatment of locoregionally recurrent breast cancer in patients who have previously undergone radiation therapy is challenging. Special techniques are often required that both eradicate the disease and minimize the risks of retreatment. We report the case of a patient with an early-stage left breast cancer who developed inflammatory-type recurrence requiring re-irradiation of the chest wall using bolus electron conformal therapy with image-guided treatment delivery. The patient was a 51-year-old woman who had undergone lumpectomy, axillary lymph node dissection, and adjuvant whole-breast radiation therapy for a stage I left breast cancer in June 1998. In March 2009, she presented at our institution with biopsy-proven recurrent inflammatory carcinoma and was aggressively treated with multi-agent chemotherapy followed by mastectomy that left a positive surgical margin. Given the patient's prior irradiation and irregular chest wall anatomy, bolus electron conformal therapy was used to treat her chest wall and draining lymphatics while sparing the underlying soft tissue. The patient still had no evidence of disease 21 months after treatment. Our results indicate that bolus electron conformal therapy is an accessible, effective radiation treatment approach for recurrent breast cancer in patients with irregular chest wall anatomy as a result of surgery. This approach may complement standard techniques used to reduce locoregional recurrence in the postmastectomy setting.

  4. Quality assurance of a conformal treatment technique

    Energy Technology Data Exchange (ETDEWEB)

    Kroes, A.P.G.; Bruinvis, I.A.D.; Lanson, J.H.; Uiterwaal, G.J. [Nederlands Kanker Inst. `Antoni van Leeuwenhoekhuis`, Amsterdam (Netherlands)

    1995-12-01

    For a parotid gland irradiation technique with a pair of oblique wedged photon beams the target coverage near the surface was investigated. The planning target volume extends to 5 millimetres under the skin; a minimum target dose of 95% is required when the dose at the centre is set to 100%. The treatment technique was simulated on a water phantom with a beam of 45 degree gantry angle, 55 degree wedge, 8 x 10 cm{sup 2} field size and the isocentre at 2 cm depth. Beam energies of 4, 6 and 8 MV were used. The dose distributions were measured in two orthogonal planes through the isocentre perpendicular to the water surface with p-type silicon diodes along lines through the isocentre every 45 degrees. Dose distributions were calculated in these planes with our 3-D planning system (U-Mplan, University of Michigan planning system), with model parameters are fitted to depth dose curves and profiles of open and wedged normally incident beams. The location of the 95% isodose was determined in five points near the surface. For 4, 6 and 8 MV the depths of the 95% isodose were 6.0, 10.3 and 11.0 mm, respectively. The depths of the 95% points of single normally incident open fields were 6.0, 9.0 and 11.5 mm, respectively. The treatment planning system (TPS) calculated the 95% isodose for the parotid technique at 5.5, 7.3 and 11.5 mm depths, for 4, 6 and 8 MV, respectively. Thus for 6 MV the 95% was 3 mm deeper than calculated by the TPS; 2 mm were caused by the inaccuracy of the open field depth dose curve fit in the build-up region. The depth near the surface of the 95% isodose for this treatment technique can be estimated from single open field depth dose curves with acceptable accuracy. This result is not obvious because the effects of the wedge and oblique incidence on the dose distribution are also involved. The TPS performed well for the 4 and 8 MV beams, but for treatments with 6 MV target under dosage could have remained undetected. (Abstract Truncated)

  5. Current treatments for radiation retinopathy

    Energy Technology Data Exchange (ETDEWEB)

    Giuliari, Gian Paolo; Simpson, E. Rand (Princess Margaret Hospital, Univ. of Toronto, Dept. of Ophthalmology and Vision Sciences, Toronto (Canada)), e-mail: gpgiuliari@gmail.com; Sadaka, Ama (Schepens Eye Research Inst., Boston, MA (United States)); Hinkle, David M. (Massachusetts Eye Research and Surgery Institution, Cambridge, MA (United States))

    2011-01-15

    Background. To review the currently available therapeutic modalities for radiation retinopathy (RR), including newer investigational interventions directed towards specific aspects of the pathophysiology of this refractory complication. Methods. A review of the literature encompassing the pathogenesis of RR and the current therapeutic modalities available was performed. Results. RR is a chronic and progressive condition that results from exposure to any source of radiation. It might be secondary to radiation treatment of intraocular tumors such as choroidal melanomas, retinoblastomas, and choroidal metastasis, or from unavoidable exposure to excessive radiation from the treatment of extraocular tumors like cephalic, nasopharyngeal, orbital, and paranasal malignancies. After the results of the Collaborative Ocular Melanoma Study, most of the choroidal melanomas are being treated with plaque brachytherapy increasing by that the incidence of this radiation complication. RR has been reported to occur in as many as 60% of eyes treated with plaque radiation, with higher rates associated with larger tumors. Initially, the condition manifests as a radiation vasculopathy clinically seen as microaneurysms and telangiectasis, with posterior development of retinal hard exudates and hemorrhages, macular edema, neovascularization and tractional retinal detachment. Regrettably, the management of these eyes remains limited. Photodynamic therapy, laser photocoagulation, oral pentoxyphylline and hyperbaric oxygen have been attempted as treatment modalities with inconclusive results. Intravitreal injections of anti-vascular endothelial growth factor such as bevacizumab, ranibizumab and pegaptanib sodium have been recently used, also with variable results. Discussion. RR is a common vision threatening complication following radiation therapy. The available therapeutic options are limited and show unsatisfactory results. Further large investigative studies are required for developing

  6. Monte Carlo conformal treatment planning as an independent assessment

    Energy Technology Data Exchange (ETDEWEB)

    Rincon, M.; Leal, A.; Perucha, M.; Carrasco, E. [Sevilla Univ. (Spain). Dept. Fisiologia Medica y Biofisica; Sanchez-Doblado, F. [Sevilla Univ. (Spain). Dept. Fisiologia Medica y Biofisica]|[Hospital Univ. Virgen Macarena, Sevilla (Spain). Servicio de Oncologia Radioterapica; Arrans, R.; Sanchez-Calzado, J.A.; Errazquin, L. [Hospital Univ. Virgen Macarena, Sevilla (Spain). Servicio de Oncologia Radioterapica; Medrano, J.C. [Clinica Puerta de Hierro, Madrid (Spain). Servicio de Radiofisica

    2001-07-01

    The wide range of possibilities available in Radiotherapy with conformal fields cannot be covered experimentally. For this reason, dosimetrical and planning procedures are based on approximate algorithms or systematic measurements. Dose distribution calculations based on Monte Carlo (MC) simulations can be used to check results. In this work, two examples of conformal field treatments are shown: A prostate carcinoma and an ocular lymphoma. The dose distributions obtained with a conventional Planning System and with MC have been compared. Some significant differences have been found. (orig.)

  7. Radiation treatment of molasses

    Science.gov (United States)

    Rodríguez, A. S.; Serrano G., J.; Lara R., O.; Reyes L., J.

    Molasses are a by-product of the sugar industry. Their annual production in México in around 1 million tons and are mainly used as a complement for animal feeding and for the production of alcohols. Their value is relatively low compared with another chemicals. When molasses are irradiated with gamma radiation or accelerated electrons, in presence of nitric acid and oxygen, it is obtained oxalic acid and several polymeric compounds. In both cases, the same products are obtained, but the yield is greater with electrons. It has been studied the effect of dose and dose rate in the yields. As example, when mixtures of molasses-nitric acid, with an initial concentration of 26% of total sugar reductors, are irradiated with 1.0 MeV electrons, in a continuous flow reactor, at 0.11 {Gy}/{sec} to a total dose of 30 KGy, the oxalic acid yield is around 44% of the total chemical reductors used. The separations of the radiolytic products was made by successive decantations and concentrations, and purified by recristallizations. From the analytical information, the minimal formula were calculated for the acid product and the polymeric compounds.

  8. Regional cancer centre demonstrates voluntary conformity with the national Radiation Oncology Practice Standards

    Energy Technology Data Exchange (ETDEWEB)

    Manley, Stephen, E-mail: stephen.manley@ncahs.health.nsw.gov.au; Last, Andrew; Fu, Kenneth; Greenham, Stuart; Kovendy, Andrew; Shakespeare, Thomas P [North Coast Cancer Institute, Lismore, New South Wales (Australia)

    2015-06-15

    Radiation Oncology Practice Standards have been developed over the last 10 years and were published for use in Australia in 2011. Although the majority of the radiation oncology community supports the implementation of the standards, there has been no mechanism for uniform assessment or governance. North Coast Cancer Institute's public radiation oncology service is provided across three main service centres on the north coast of NSW. With a strong focus on quality management, we embraced the opportunity to demonstrate conformity with the Radiation Oncology Practice Standards. The Local Health District's Clinical Governance units were engaged to perform assessments of our conformity with the standards and this was signed off as complete on 16 December 2013. The process of demonstrating conformity with the Radiation Oncology Practice Standards has enhanced the culture of quality in our centres. We have demonstrated that self-assessment utilising trained auditors is a viable method for centres to demonstrate conformity. National implementation of the Radiation Oncology Practice Standards will benefit individual centres and the broader radiation oncology community to improve the service delivered to our patients.

  9. Vacuum Radiation and Symmetry Breaking in Conformally Invariant Quantum Field Theory

    CERN Document Server

    Aldaya, V; Cerveró, J M

    1999-01-01

    The underlying reasons for the difficulty of unitarily implementing the whole conformal group $SO(4,2)$ in a massless Quantum Field Theory (QFT) are investigated in this paper. Firstly, we demonstrate that the singular action of the subgroup of special conformal transformations (SCT), on the standard Minkowski space $M$, cannot be primarily associated with the vacuum radiation problems, the reason being more profound and related to the dynamical breakdown of part of the conformal symmetry (the SCT subgroup, to be more precise) when representations of null mass are selected inside the representations of the whole conformal group. Then we show how the vacuum of the massless QFT radiates under the action of SCT (usually interpreted as transitions to a uniformly accelerated frame) and we calculate exactly the spectrum of the outgoing particles, which proves to be a generalization of the Planckian one, this recovered as a given limit.

  10. Disease Control After Reduced Volume Conformal and Intensity Modulated Radiation Therapy for Childhood Craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [St Jude Children' s Research Hospital, Radiological Sciences, Memphis, Tennessee (United States); Kun, Larry E.; Hua, Chia-Ho [St Jude Children' s Research Hospital, Radiological Sciences, Memphis, Tennessee (United States); Wu, Shengjie; Xiong, Xiaoping [St Jude Children' s Research Hospital, Biostatistics, Memphis, Tennessee (United States); Sanford, Robert A.; Boop, Frederick A. [Semmes Murphey Neurologic and Spine Institute, Neurosurgery, Memphis, Tennessee (United States)

    2013-03-15

    Purpose: To estimate the rate of disease control after conformal radiation therapy using reduced clinical target volume (CTV) margins and to determine factors that predict for tumor progression. Methods and Materials: Eighty-eight children (median age, 8.5 years; range, 3.2-17.6 years) received conformal or intensity modulated radiation therapy between 1998 and 2009. The study group included those prospectively treated from 1998 to 2003, using a 10-mm CTV, defined as the margin surrounding the solid and cystic tumor targeted to receive the prescription dose of 54 Gy. The CTV margin was subsequently reduced after 2003, yielding 2 groups of patients: those treated with a CTV margin greater than 5 mm (n=26) and those treated with a CTV margin less than or equal to 5 mm (n=62). Disease progression was estimated on the basis of additional variables including sex, race, extent of resection, tumor interventions, target volume margins, and frequency of weekly surveillance magnetic resonance (MR) imaging during radiation therapy. Median follow-up was 5 years. Results: There was no difference between progression-free survival rates based on CTV margins (>5 mm vs ≤5 mm) at 5 years (88.1% ± 6.3% vs 96.2% ± 4.4% [P=.6386]). There were no differences based on planning target volume (PTV) margins (or combined CTV plus PTV margins). The PTV was systematically reduced from 5 to 3 mm during the time period of the study. Factors predictive of superior progression-free survival included Caucasian race (P=.0175), no requirement for cerebrospinal fluid shunting (P=.0066), and number of surveillance imaging studies during treatment (P=.0216). Patients whose treatment protocol included a higher number of weekly surveillance MR imaging evaluations had a lower rate of tumor progression. Conclusions: These results suggest that targeted volume reductions for radiation therapy using smaller margins are feasible and safe but require careful monitoring. We are currently investigating

  11. A conformal approach for the analysis of the non-linear stability of radiation cosmologies

    Energy Technology Data Exchange (ETDEWEB)

    Luebbe, Christian, E-mail: c.luebbe@ucl.ac.uk [Department of Mathematics, University College London, Gower Street, London, WC1E 6BT (United Kingdom); Department of Mathematics, University of Leicester, University Road, LE1 8RH (United Kingdom); Valiente Kroon, Juan Antonio, E-mail: j.a.valiente-kroon@qmul.ac.uk [School of Mathematical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS (United Kingdom)

    2013-01-15

    The conformal Einstein equations for a trace-free (radiation) perfect fluid are derived in terms of the Levi-Civita connection of a conformally rescaled metric. These equations are used to provide a non-linear stability result for de Sitter-like trace-free (radiation) perfect fluid Friedman-Lemaitre-Robertson-Walker cosmological models. The solutions thus obtained exist globally towards the future and are future geodesically complete. - Highlights: Black-Right-Pointing-Pointer We study the Einstein-Euler system in General Relativity using conformal methods. Black-Right-Pointing-Pointer We analyze the structural properties of the associated evolution equations. Black-Right-Pointing-Pointer We establish the non-linear stability of pure radiation cosmological models.

  12. Design and analysis of a conformal patch antenna for a wearable breast hyperthermia treatment system

    Science.gov (United States)

    Curto, Sergio; Ramasamy, Manoshika; Suh, Minyoung; Prakash, Punit

    2015-03-01

    To overcome the limitations of currently available clinical hyperthermia systems which are based on rigid waveguide antennas, a wearable microwave hyperthermia system is presented. A light wearable system can improve patient comfort and be located in close proximity to the breast, thereby enhancing energy deposition and reducing power requirements. The objective of this work was to design and assess the feasibility of a conformal patch antenna element of an array system to be integrated into a wearable hyperthermia bra. The feasibility of implementing antennas with silver printed ink technology on flexible substrates was evaluated. A coupled electromagnetic-bioheat transfer solver and a hemispheric heterogeneous numerical breast phantom were used to design and optimize a 915 MHz patch antenna. The optimization goals were device miniaturization, operating bandwidth, enhanced energy deposition pattern in targets, and reduced Efield back radiation. The antenna performance was evaluated for devices incorporating a hemispheric conformal groundplane and a rectangular groundplane configuration. Simulated results indicated a stable -10 dB return loss bandwidth of 88 MHz for both the conformal and rectangular groundplane configurations. Considering applied power levels restricted to 15 W, treatment volumes (T>410C) and depth from the skin surface were 11.32 cm3 and 27.94 mm, respectively, for the conformal groundplane configuration, and 2.79 cm3 and 19.72 mm, respectively, for the rectangular groundplane configuration. E-field back-radiation reduced by 85.06% for the conformal groundplane compared to the rectangular groundplane configuration. A prototype antenna with rectangular groundplane was fabricatd and experimentally evaluated. The groundplane was created by printing silver ink (Metalon JS-B25P) on polyethylene terephthalate (PET) film surface. Experiments revealed stable antenna performance for power levels up to 15.3 W. In conclusion, the proposed patch antenna with

  13. Evaluation of flexible and rigid (class solution) radiation therapy conformal prostate planning protocols.

    Science.gov (United States)

    Coburn, Natalie; Beldham-Collins, Rachael; Westling, Jelene; Trovato, Jenny; Gebski, Val

    2012-01-01

    Protocols commonly implemented in radiotherapy work areas may be classified as being either rigid (class solution) or flexible. Because formal evaluation of these protocol types has not occurred within the literature, we evaluated the efficiency of a rigid compared with flexible prostate planning protocol by assessing a series of completed 3D conformal prostate plans. Twenty prostate cancer patients with an average age of 70 years (range, 52-77) and sizes comprising 8 small, 10 medium, and 2 large were planned on the Phillips Pinnacle treatment planning system 6 times by radiation therapists with 5 years of experience using a rigid and flexible protocol. Plans were critiqued using critical organ doses, confirmation numbers, and conformity index. Plans were then classified as being acceptable or not. Plans produced with the flexible protocol were 53% less likely to require modification (OR 0.47, 95% CI: 0.26, 0.84, p = 0.01). Planners with >5 years of experience were 78% more likely to produce plans requiring modification (OR 1.78, 95% CI: 1.12, 2.83, P = 0.02). Plans according to the flexible protocol took longer (112 min) compared with the time taken using a rigid protocol (68 min) (p < 0.001). The results suggest that further studies are needed; however, we propose that all radiation therapy planners should start with the same limitations, and if an acceptable plan is not reached, then flexibility should be given to improve the plan to meet the desired results. Crown Copyright © 2012. Published by Elsevier Inc. All rights reserved.

  14. Cost-Effectiveness Analysis of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Anal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Hodges, Joseph C., E-mail: joseph.hodges@utsouthwestern.edu [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Beg, Muhammad S. [Division of Hematology and Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States); Das, Prajnan [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Meyer, Jeffrey [Department of Radiation Oncology, University of Texas Southwestern Medical Center, Dallas, Texas (United States)

    2014-07-15

    Purpose: To compare the cost-effectiveness of intensity modulated radiation therapy (IMRT) and 3-dimensional conformal radiation therapy (3D-CRT) for anal cancer and determine disease, patient, and treatment parameters that influence the result. Methods and Materials: A Markov decision model was designed with the various disease states for the base case of a 65-year-old patient with anal cancer treated with either IMRT or 3D-CRT and concurrent chemotherapy. Health states accounting for rates of local failure, colostomy failure, treatment breaks, patient prognosis, acute and late toxicities, and the utility of toxicities were informed by existing literature and analyzed with deterministic and probabilistic sensitivity analysis. Results: In the base case, mean costs and quality-adjusted life expectancy in years (QALY) for IMRT and 3D-CRT were $32,291 (4.81) and $28,444 (4.78), respectively, resulting in an incremental cost-effectiveness ratio of $128,233/QALY for IMRT compared with 3D-CRT. Probabilistic sensitivity analysis found that IMRT was cost-effective in 22%, 47%, and 65% of iterations at willingness-to-pay thresholds of $50,000, $100,000, and $150,000 per QALY, respectively. Conclusions: In our base model, IMRT was a cost-ineffective strategy despite the reduced acute treatment toxicities and their associated costs of management. The model outcome was sensitive to variations in local and colostomy failure rates, as well as patient-reported utilities relating to acute toxicities.

  15. Blackbody radiation, conformal symmetry, and the mismatch between classical mechanics and electromagnetism

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Timothy H [Department of Physics, City College of the City University of New York, New York, NY 10031 (United States)

    2005-02-25

    The blackbody radiation problem within classical physics is reviewed. It is again suggested that conformal symmetry is the crucial unrecognized aspect, and that only scattering by classical electromagnetic systems will provide equilibrium at the Planck spectrum. It is pointed out that the several calculations of radiation scattering using nonlinear mechanical systems do not preserve the Boltzmann distribution under adiabatic change of a parameter, and this fact seems at variance with our expectations in connection with derivations of Wien's displacement theorem. By contrast, the striking properties of charged particle motion in a Coulomb potential or in a uniform magnetic field suggest the possibility that these systems will fit with classical thermal radiation. It may be possible to give a full scattering calculation in the case of cyclotron motion in order to provide the needed test of the connection between conformal symmetry and classical thermal radiation.

  16. Emotional and Behavioral Functioning After Conformal Radiation Therapy for Pediatric Ependymoma

    Energy Technology Data Exchange (ETDEWEB)

    Willard, Victoria W.; Conklin, Heather M. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Boop, Frederick A. [Department of Surgery, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Department of Neurosurgery, Semmes-Murphey Neurologic and Spine Institute, Memphis, Tennessee (United States); Wu, Shengjie [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2014-03-15

    Purpose: The standard of care for pediatric patients with ependymoma involves postoperative radiation therapy. Prior research suggests that conformal radiation therapy (CRT) is associated with relative sparing of cognitive and academic functioning, but little is known about the effect of CRT on emotional and behavioral functioning. Methods and Materials: A total of 113 patients with pediatric ependymoma underwent CRT using photons as part of their enrollment on an institutional trial. Patients completed annual evaluations of neurocognitive functioning during the first 5 years after CRT. Emotional and behavioral functioning was assessed via the Child Behavior Checklist. Results: Before CRT, emotional and behavioral functioning were commensurate with those of the normative population and within normal limits. After 5 years, means remained within normal limits but were significantly below the normative mean. Linear mixed models revealed a significant increase in attention problems over time. These problems were associated with age at diagnosis/CRT, tumor location, and extent of resection. A higher-than-expected incidence of school problems was present at all assessment points after baseline. Conclusions: The use of photon CRT for ependymoma is associated with relatively stable emotional and behavioral functioning during the first 5 years after treatment. The exception is an increase in attention problems. Results suggest that intervening earlier in the survivorship period—during the first year posttreatment—may be beneficial.

  17. Assessment and Comparison of Homogeneity and Conformity Indexes in Step-and-Shoot and Compensator-Based Intensity Modulated Radiation Therapy (IMRT) and Three-Dimensional Conformal Radiation Therapy (3D CRT) in Prostate Cancer.

    Science.gov (United States)

    Salimi, Marzieh; Abi, Kaveh Shirani Tak; Nedaie, Hassan Ali; Hassani, Hossein; Gharaati, Hussain; Samei, Mahmood; Shahi, Rezgar; Zarei, Hamed

    2017-01-01

    Intensity modulated radiation therapy (IMRT) and three-dimensional conformal radiation therapy (3D CRT) are two treatment modalities in prostate cancer, which provide acceptable dose distribution in tumor region with sparing the surrounding normal tissues. IMRT is based on inverse planning optimization; in which, intensity of beams is modified by using multileaf collimators and also compensators with optimum shapes in step and shoot (SAS) and compensator-based method, respectively. In the recent study, some important parameters were compared in two IMRT and 3D CRT methods. Prescribed dose was 80 Gy for both IMRT procedures and 70 Gy for 3D CRT. Treatment plans of 15 prostate cancer candidates were compared to target the minimum dose, maximum dose, V 76 Gy (for IMRT plans) V 66.5 Gy (for 3D CRT), mean dose, conformity index (CI), and homogeneity index (HI). Dose conformity in compensators-based IMRT was better than SAS and 3D CRT. The same outcome was also achieved for homogeneity index. The target coverage was achieved 95% of prescribed dose to 95% of planning target volume (PTV) in 3D CRT and 95% of prescribed dose to 98% of PTV in IMRT methods. IMRT increases maximum dose of tumor region, improves CI and HI of target volume, and also reduces dose of organs at risks.

  18. On conformally flat and type N pure radiation metrics

    CERN Document Server

    Podolsky, Jiri

    2009-01-01

    We study pure radiation spacetimes of algebraic types O and N with a possible cosmological constant. In particular, we present explicit transformations which put these metrics, that were recently re-derived by Edgar, Vickers and Machado Ramos, into a general Ozsvath-Robinson-Rozga form. By putting all such metrics into the unified coordinate system we confirm that their derivation based on the GIF formalism is correct. We identify only few trivial differences.

  19. Performances study of UWB monopole antennas using half-elliptic radiator conformed on elliptical surface

    Science.gov (United States)

    Djidel, S.; Bouamar, M.; Khedrouche, D.

    2016-04-01

    This paper presents a performances study of UWB monopole antenna using half-elliptic radiator conformed on elliptical surface. The proposed antenna, simulated using microwave studio computer CST and High frequency simulator structure HFSS, is designed to operate in frequency interval over 3.1 to 40 GHz. Good return loss and radiation pattern characteristics are obtained in the frequency band of interest. The proposed antenna structure is suitable for ultra-wideband applications, which is, required for many wearable electronics applications.

  20. Conforming to cancer staging, prognostic indicators and national treatment guidelines.

    Science.gov (United States)

    Dykstra-Long, Gwendylen R

    2011-01-01

    Clinical cancer staging and prognostic indicators guide treatment planning, and as such the American College of Surgeons Commission on Cancer Commission on Cancer (ACoS CoC) and the American Joint Committee on Cancer (AJCC) have recognized this as quality patient care. Overton Brooks Veterans Administration (OBVAMC) developed an organizational policy and procedure, flow algorithms, treatment plan templates, and education strategies in order to conform to this quality care approach. The purpose of this article is to share this systematic approach that is able to support clinical and working cancer stage and prognostic indicators which have been recognized by national standard setting organizations as quality patient care.

  1. Integral Dose and Radiation-Induced Secondary Malignancies: Comparison between Stereotactic Body Radiation Therapy and Three-Dimensional Conformal Radiotherapy

    Science.gov (United States)

    D’Arienzo, Marco; Masciullo, Stefano G.; de Sanctis, Vitaliana; Osti, Mattia F.; Chiacchiararelli, Laura; Enrici, Riccardo M.

    2012-01-01

    The aim of the present paper is to compare the integral dose received by non-tumor tissue (NTID) in stereotactic body radiation therapy (SBRT) with modified LINAC with that received by three-dimensional conformal radiotherapy (3D-CRT), estimating possible correlations between NTID and radiation-induced secondary malignancy risk. Eight patients with intrathoracic lesions were treated with SBRT, 23 Gy × 1 fraction. All patients were then replanned for 3D-CRT, maintaining the same target coverage and applying a dose scheme of 2 Gy × 32 fractions. The dose equivalence between the different treatment modalities was achieved assuming α/β = 10Gy for tumor tissue and imposing the same biological effective dose (BED) on the target (BED = 76Gy10). Total NTIDs for both techniques was calculated considering α/β = 3Gy for healthy tissue. Excess absolute cancer risk (EAR) was calculated for various organs using a mechanistic model that includes fractionation effects. A paired two-tailed Student t-test was performed to determine statistically significant differences between the data (p ≤ 0.05). Our study indicates that despite the fact that for all patients integral dose is higher for SBRT treatments than 3D-CRT (p = 0.002), secondary cancer risk associated to SBRT patients is significantly smaller than that calculated for 3D-CRT (p = 0.001). This suggests that integral dose is not a good estimator for quantifying cancer induction. Indeed, for the model and parameters used, hypofractionated radiotherapy has the potential for secondary cancer reduction. The development of reliable secondary cancer risk models seems to be a key issue in fractionated radiotherapy. Further assessments of integral doses received with 3D-CRT and other special techniques are also strongly encouraged. PMID:23202843

  2. Optimisation of beam-orientations in conformal radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Rowbottom, C.G

    1999-07-01

    Many synergistic advances have led to the beginnings of the routine use of conformal radiotherapy. These include advances in diagnostic imaging, in 3D treatment planning, in the technology for complex treatment delivery and in computer assessment of rival treatment plans. A conformal radiotherapy treatment plan more closely conforms the high-dose volume to the target volume, reducing the dose to normal healthy tissue. Traditionally, human planners have devised the treatment parameters used in radiotherapy treatment plans via a manually iterative process. Computer 'optimisation' algorithms have been shown to improve treatment plans as they can explore much more of the search space in a relatively short time. This thesis examines beam-orientation computer 'optimisation' in radiotherapy treatment planning and several new techniques were developed. Using these techniques a comparison was performed between treatment plans with 'standard', fixed beam-orientations and treatment plans with 'optimised' beam-orientations for patients with cancer of the prostate, oesophagus and brain. Plans were compared on the basis of dose-distributions and in some cases biological models for the probability of damage to the target volume and the major organs-at-risk (OARs) in each patient group. A cohort of patients was considered in each group to avoid bias from a specific patient geometry. In the case of the patient cohort with cancer of the prostate, a coplanar beam-orientation 'optimisation' scheme led to an average increase in the TCP of (5.7{+-}1.4)% compared to the standard plans after the dose to the isocentre had been scaled to produce a rectal NTCP of 1%. For the patient cohort with cancer of the oesophagus, the beam-orientation 'optimisation' scheme reduced the average lung NTCP by (0.7{+-}0.2)% at the expense of a modest increase in the average spinal cord NTCP of (0.1{+-}0.2)%. A non-coplanar beam-orientation &apos

  3. Improved Modeling of Open Waveguide Aperture Radiators for use in Conformal Antenna Arrays

    Science.gov (United States)

    Nelson, Gregory James

    Open waveguide apertures have been used as radiating elements in conformal arrays. Individual radiating element model patterns are used in constructing overall array models. The existing models for these aperture radiating elements may not accurately predict the array pattern for TEM waves which are not on boresight for each radiating element. In particular, surrounding structures can affect the far field patterns of these apertures, which ultimately affects the overall array pattern. New models of open waveguide apertures are developed here with the goal of accounting for the surrounding structure effects on the aperture far field patterns such that the new models make accurate pattern predictions. These aperture patterns (both E plane and H plane) are measured in an anechoic chamber and the manner in which they deviate from existing model patterns are studied. Using these measurements as a basis, existing models for both E and H planes are updated with new factors and terms which allow the prediction of far field open waveguide aperture patterns with improved accuracy. These new and improved individual radiator models are then used to predict overall conformal array patterns. Arrays of open waveguide apertures are constructed and measured in a similar fashion to the individual aperture measurements. These measured array patterns are compared with the newly modeled array patterns to verify the improved accuracy of the new models as compared with the performance of existing models in making array far field pattern predictions. The array pattern lobe characteristics are then studied for predicting fully circularly conformal arrays of varying radii. The lobe metrics that are tracked are angular location and magnitude as the radii of the conformal arrays are varied. A constructed, measured array that is close to conforming to a circular surface is compared with a fully circularly conformal modeled array pattern prediction, with the predicted lobe angular locations and

  4. Conformal three dimensional radiotherapy treatment planning in Lund

    Energy Technology Data Exchange (ETDEWEB)

    Knoos, T.; Nilsson, P. [Lund Univ. (Sweden). Dept. of Radiation Physics; Anders, A. [Lund Univ. (Sweden). Dept. of Oncology

    1995-12-01

    The use of conformal therapy is based on 3-dimensional treatment planning as well as on methods and routines for 3-dimensional patient mapping, 3-dimensional virtual simulation and others. The management of patients at the Radiotherapy Department at the University Hospital in Lund (Sweden) is discussed. About 2100 new patients are annually treated with external radiotherapy using seven linear accelerators. Three of the accelerators have dual photon energies and electron treatment facilities. A multi-leaf collimator as well as an electronic portal imaging device are available on one machine. Two simulators and an in-house CT-scanner are used for treatment planning. From 1988 to 1992 Scandiplan (Umplan) was used. Since 1992, the treatment planning system is TMS (HELAX AB, Sweden), which is based on the pencil beam algorithm of Ahnesjo. The calculations use patient modulated accelerator specific energy fluence spectra which are compiled with pencil beams from Monte Carlo generated energy absorption kernels. Heterogeneity corrections are performed with results close to conventional algorithms. Irregular fields, either from standard or individual blocks and from multi-leaf collimators are handled by the treatment planning system. The field shape is determined conveniently using the beam`s eye view. The final field shape is exported electronically to either the block cutting machine or the multileaf collimator control computer. All patient fields are checked against the beam`s eye view during simulation using manual methods. Treatment verification is performed by portal films and in vivo dosimetry with silicon diodes or TL-dosimetry. Up to now, approximately 4400 patients have received a highly individualized 3-dimensional conformal treatment.

  5. Learning and Memory Following Conformal Radiation Therapy for Pediatric Craniopharyngioma and Low-Grade Glioma

    Energy Technology Data Exchange (ETDEWEB)

    Di Pinto, Marcos [Department of Pediatric Psychology, Children' s Hospital of Orange County, Orange, California (United States); Conklin, Heather M. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Li, Chenghong [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2012-11-01

    Purpose: The primary objective of this study was to examine whether children with low-grade glioma (LGG) or craniopharyngioma had impaired learning and memory after conformal radiation therapy (CRT). A secondary objective was to determine whether children who received chemotherapy before CRT, a treatment often used to delay radiation therapy in younger children with LGG, received any protective benefit with respect to learning. Methods and Materials: Learning and memory in 57 children with LGG and 44 children with craniopharyngioma were assessed with the California Verbal Learning Test-Children's Version and the Visual-Auditory Learning tests. Learning measures were administered before CRT, 6 months later, and then yearly for a total of 5 years. Results: No decline in learning scores after CRT was observed when patients were grouped by diagnosis. For children with LGG, chemotherapy before CRT did not provide a protective effect on learning. Multiple regression analyses, which accounted for age and tumor volume and location, found that children treated with chemotherapy before CRT were at greater risk of decline on learning measures than those treated with CRT alone. Variables predictive of learning and memory decline included hydrocephalus, shunt insertion, younger age at time of treatment, female gender, and pre-CRT chemotherapy. Conclusions: This study did not reveal any impairment or decline in learning after CRT in overall aggregate learning scores. However, several important variables were found to have a significant effect on neurocognitive outcome. Specifically, chemotherapy before CRT was predictive of worse outcome on verbal learning in LGG patients. In addition, hydrocephalus and shunt insertion in craniopharyngioma were found to be predictive of worse neurocognitive outcome, suggesting a more aggressive natural history for those patients.

  6. Three-dimensional Conformal Radiation Therapy Techniques for Rectal Cancer

    NARCIS (Netherlands)

    J.J.M.E. Nuyttens (Joost)

    2004-01-01

    markdownabstract__Abstract__ The third most common malignancy in the Netherlands is colorectal cancer. Rectal cancer affects every year around 2000 new patients. The highest incidence is found at an age above 70 years, and in men (sex ratio: 1.48). In Europe, the treatment of preference for locally

  7. Three-dimensional conformal intensity-modulated radiation therapy of left femur foci does not damage the sciatic nerve

    Institute of Scientific and Technical Information of China (English)

    Wanlong Xu; Xibin Zhao; Qing Wang; Jungang Sun; Jiangbo Xu; Wenzheng Zhou; Hao Wang; Shigui Yan; Hong Yuan

    2014-01-01

    During radiotherapy to kill femoral hydatid tapeworms, the sciatic nerve surrounding the focus can be easily damaged by the treatment. Thus, it is very important to evaluate the effects of ra-diotherapy on the surrounding nervous tissue. In the present study, we used three-dimensional, conformal, intensity-modulated radiation therapy to treat bilateral femoral hydatid disease in Meriones meridiani. The focus of the hydatid disease on the left femur was subjected to radio-therapy (40 Gy) for 14 days, and the right femur received sham irradiation. Hematoxylin-eosin staining, electron microscopy, and terminal deoxynucleotidyl transferase-dUTP nick end labeling assays on the left femurs showed that the left sciatic nerve cell structure was normal, with no ob-vious apoptosis after radiation. Trypan blue staining demonstrated that the overall protoscolex structure in bone parasitized withEchinococcus granulosus disappeared in the left femur of the animals after treatment. The mortality of the protoscolex was higher in the left side than in the right side. The succinate dehydrogenase activity in the protoscolex in bone parasitized withEchi-nococcus granulosus was lower in the left femur than in the right femur. These results suggest that three-dimensional conformal intensity-modulated radiation therapy achieves good therapeutic effects on the secondary bone in hydatid disease inMeriones meridiani without damaging the morphology or function of the sciatic nerve.

  8. 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....

  9. Preliminary analysis of a clinical trial for threedimensional conformal radiation therapy after conservative surgery

    Institute of Scientific and Technical Information of China (English)

    Hui Yao; Jinlan Gong; Li Li; Yun Wang; Xiaofeng Wu; Kezhu Hou

    2012-01-01

    Objective: The aim of this study was to evaluate the efficacy, complications and cosmetic results of three-dimensional conformal radiation therapy for early breast cancer after conservative surgery. Methods: Among 80 patients, 44 were treated by modified radical mastectomy followed by adjuvant radiotherapy (modified radical mastectomy, MMT), 36 were treated with breast conservative surgery with adjuvant irradiation [breast-conservation therapy (BCT)]. Tangential fields were used to deliver 6 MV X-ray beams to a total dose of 50 Gy. Another 16 Gy was added to the tumor bed with 6-9 MeV electron beams for BCT. Results: In MMT group, the local control, metastasis-free and death were 41, 41 and 1 respectively; in BCT group, the local control, metastasis-free and death were 35, 35 and 0. The difference of the above two indicators between the two groups showeed no statistical insignificance (P > 0. 05). In MMT group, 32 patients suffer radiation dermatitis above 2-level, 12 patients suffer radiation pneumonia, and 10 patients suffer edema of illness-side upper extremity; in BCT group, the above indicators were only 6, 2 and 1 respectively. Three months, six months and one year after radiation therapy, 90%, 92% and 95% patients were assessed as excellence in fine cosmetic state in BCT group. Conclusion: The effects of threedimensional conformal radiation therapy after conservative surgery are the same as that of modified radical mastectomy, while the former has better cosmetic results and lower radiation therapy induced complications.

  10. CONSERVATIVE TREATMENT IN LOCALLY AND LOCALLY-ADVANCED PROSTATE CANCER USING CONFORMAL RADIOTHERAPY

    Directory of Open Access Journals (Sweden)

    Tkachev Sergey Ivanovich

    2013-01-01

    Full Text Available The combination of androgen deprivation and radiotherapy increase the probability of diseases full regresses and survival rate. Modern technical and technological opportunities of 3D CRT allow to increase total dose to prostate up to 72-76Gy vs. radiotherapy of 66-70Gy. In this study we compare the rates of post radiation toxicity and the efficiency of treatment for the patients receiving conventional radiotherapy and 3D CRT. The use of 3D CRT has not only result to increase of 10-years recurrence free survival rate from 74% (I grope to 86,5% (II grope, р=0,01, but also to increase of 10-years overall survival, 70% versus 78,4% (р=0,04. The proposed version of conformal 3D CRT radiation therapy made ​​it possible compared to conventional 2D RT radiation therapy by increasing SOD radiation to the tumor, accuracy and compliance with the quality assurance of radiation therapy significantly reduce rates of recurrence and significantly increase the performance of 10-year overall and disease-free survival.

  11. Potential for Improved Intelligence Quotient Using Volumetric Modulated Arc Therapy Compared With Conventional 3-Dimensional Conformal Radiation for Whole-Ventricular Radiation in Children

    Energy Technology Data Exchange (ETDEWEB)

    Qi, X. Sharon, E-mail: xqi@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine at UCLA, Los Angeles, California (United States); Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Stinauer, Michelle; Rogers, Brion [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Madden, Jennifer R. [Department of Neuro-Oncology, The Children' s Hospital, Aurora, Colorado (United States); Wilkening, Greta N. [Department of Pediatrics, The Children' s Hospital, Aurora, Colorado (United States); Liu, Arthur K. [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States)

    2012-12-01

    Purpose: To compare volumetric modulated arc therapy (VMAT) with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of localized intracranial germinoma. We modeled the effect of the dosimetric differences on intelligence quotient (IQ). Method and Materials: Ten children with intracranial germinomas were used for planning. The prescription doses were 23.4 Gy to the ventricles followed by 21.6 Gy to the tumor located in the pineal region. For each child, a 3D-CRT and full arc VMAT was generated. Coverage of the target was assessed by computing a conformity index and heterogeneity index. We also generated VMAT plans with explicit temporal lobe sparing and with smaller ventricular margin expansions. Mean dose to the temporal lobe was used to estimate IQ 5 years after completion of radiation, using a patient age of 10 years. Results: Compared with the 3D-CRT plan, VMAT improved conformality (conformity index 1.10 vs 1.85), with slightly higher heterogeneity (heterogeneity index 1.09 vs 1.06). The averaged mean doses for left and right temporal lobes were 31.3 and 31.7 Gy, respectively, for VMAT plans and 37.7 and 37.6 Gy for 3D-CRT plans. This difference in mean temporal lobe dose resulted in an estimated IQ difference of 3.1 points at 5 years after radiation therapy. When the temporal lobes were explicitly included in the VMAT optimization, the mean temporal lobe dose was reduced 5.6-5.7 Gy, resulting in an estimated IQ difference of an additional 3 points. Reducing the ventricular margin from 1.5 cm to 0.5 cm decreased mean temporal lobe dose 11.4-13.1 Gy, corresponding to an estimated increase in IQ of 7 points. Conclusion: For treatment of children with intracranial pure germinomas, VMAT compared with 3D-CRT provides increased conformality and reduces doses to normal tissue. This may result in improvements in IQ in these children.

  12. Potential for improved intelligence quotient using volumetric modulated arc therapy compared with conventional 3-dimensional conformal radiation for whole-ventricular radiation in children.

    Science.gov (United States)

    Qi, X Sharon; Stinauer, Michelle; Rogers, Brion; Madden, Jennifer R; Wilkening, Greta N; Liu, Arthur K

    2012-12-01

    To compare volumetric modulated arc therapy (VMAT) with 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of localized intracranial germinoma. We modeled the effect of the dosimetric differences on intelligence quotient (IQ). Ten children with intracranial germinomas were used for planning. The prescription doses were 23.4 Gy to the ventricles followed by 21.6 Gy to the tumor located in the pineal region. For each child, a 3D-CRT and full arc VMAT was generated. Coverage of the target was assessed by computing a conformity index and heterogeneity index. We also generated VMAT plans with explicit temporal lobe sparing and with smaller ventricular margin expansions. Mean dose to the temporal lobe was used to estimate IQ 5 years after completion of radiation, using a patient age of 10 years. Compared with the 3D-CRT plan, VMAT improved conformality (conformity index 1.10 vs 1.85), with slightly higher heterogeneity (heterogeneity index 1.09 vs 1.06). The averaged mean doses for left and right temporal lobes were 31.3 and 31.7 Gy, respectively, for VMAT plans and 37.7 and 37.6 Gy for 3D-CRT plans. This difference in mean temporal lobe dose resulted in an estimated IQ difference of 3.1 points at 5 years after radiation therapy. When the temporal lobes were explicitly included in the VMAT optimization, the mean temporal lobe dose was reduced 5.6-5.7 Gy, resulting in an estimated IQ difference of an additional 3 points. Reducing the ventricular margin from 1.5 cm to 0.5 cm decreased mean temporal lobe dose 11.4-13.1 Gy, corresponding to an estimated increase in IQ of 7 points. For treatment of children with intracranial pure germinomas, VMAT compared with 3D-CRT provides increased conformality and reduces doses to normal tissue. This may result in improvements in IQ in these children. Copyright © 2012 Elsevier Inc. All rights reserved.

  13. Selection of candidate wells and optimization of conformance treatment design in the Barrancas Field using a 3D conformance simulator

    Energy Technology Data Exchange (ETDEWEB)

    Crosta, Dante; Elitseche, Luis [Repsol YPF (Argentina); Gutierrez, Mauricio; Ansah, Joe; Everett, Don [Halliburton Argentina S.A., Buenos Aires (Argentina)

    2004-07-01

    Minimizing the amount of unwanted water production is an important goal at the Barrancas field. This paper describes a selection process for candidate injection wells that is part of a pilot conformance project aimed at improving vertical injection profiles, reducing water cut in producing wells, and improving ultimate oil recovery from this field. The well selection process is based on a review of limited reservoir information available for this field to determine inter-well communications. The methodology focuses on the best use of available information, such as production and injection history, well intervention files, open hole logs and injectivity surveys. After the candidate wells were selected and potential water injection channels were identified, conformance treatment design and future performance of wells in the selected pilot area were evaluated using a new 3 -D conformance simulator, developed specifically for optimization of the design and placement of unwanted fluid shut-off treatments. Thus, when acceptable history match ing of the pilot area production was obtained, the 3 -D simulator was used to: evaluate the required volume of selected conformance treatment fluid; review expected pressures and rates during placement;. model temperature behavior; evaluate placement techniques, and forecast water cut reduction and incremental oil recovery from the producers in this simulated section of the pilot area. This paper outlines a methodology for selecting candidate wells for conformance treatments. The method involves application of several engineering tools, an integral component of which is a user-friendly conformance simulator. The use of the simulator has minimized data preparation time and allows the running of sensitivity cases quickly to explore different possible scenarios that best represent the reservoir. The proposed methodology provides an efficient means of identifying conformance problems and designing optimized solutions for these individual

  14. A 5-Year Investigation of Children's Adaptive Functioning Following Conformal Radiation Therapy for Localized Ependymoma

    Energy Technology Data Exchange (ETDEWEB)

    Netson, Kelli L.; Conklin, Heather M. [Department of Psychology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Wu Shengjie; Xiong Xiaoping [Department of Biostatistics, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States); Merchant, Thomas E., E-mail: thomas.merchant@stjude.org [Division of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, Tennessee (United States)

    2012-09-01

    Purpose: Conformal and intensity modulated radiation therapies have the potential to preserve cognitive outcomes in children with ependymoma; however, functional behavior remains uninvestigated. This longitudinal investigation prospectively examined intelligence quotient (IQ) and adaptive functioning during the first 5 years after irradiation in children diagnosed with ependymoma. Methods and Materials: The study cohort consisted of 123 children with intracranial ependymoma. Mean age at irradiation was 4.60 years (95% confidence interval [CI], 3.85-5.35). Serial neurocognitive evaluations, including an age-appropriate IQ measure and the Vineland Adaptive Behavior Scales (VABS), were completed before irradiation, 6 months after treatment, and annually for 5 years. A total of 579 neurocognitive evaluations were included in these analyses. Results: Baseline IQ and VABS were below normative means (P<.05), although within the average range. Linear mixed models revealed stable IQ and VABS across the follow-up period, except for the VABS Communication Index, which declined significantly (P=.015). Annual change in IQ (-.04 points) did not correlate with annual change in VABS (-.90 to +.44 points). Clinical factors associated with poorer baseline performance (P<.05) included preirradiation chemotherapy, cerebrospinal fluid shunt placement, number and extent of surgical resections, and younger age at treatment. No clinical factors significantly affected the rate of change in scores. Conclusions: Conformal and intensity modulated radiation therapies provided relative sparing of functional outcomes including IQ and adaptive behaviors, even in very young children. Communication skills remained vulnerable and should be the target of preventive and rehabilitative interventions.

  15. A 5-Year Investigation of Children’s Adaptive Functioning Following Conformal Radiation Therapy for Localized Ependymoma

    Science.gov (United States)

    Netson, Kelli L.; Conklin, Heather M.; Wu, Shengjie; Xiong, Xiaoping; Merchant, Thomas E.

    2012-01-01

    Purpose Conformal and intensity modulated radiation therapies have the potential to preserve cognitive outcomes in children with ependymoma; however, functional behavior remains uninvestigated. This longitudinal investigation prospectively examined intelligence quotient (IQ) and adaptive functioning during the first 5 years after irradiation in children diagnosed with ependymoma. Methods and Materials The study cohort consisted of 123 children with intracranial ependymoma. Mean age at irradiation was 4.60 years (95% confidence interval [CI], 3.85–5.35). Serial neurocognitive evaluations, including an age-appropriate IQ measure and the Vineland Adaptive Behavior Scales (VABS), were completed before irradiation, 6 months after treatment, and annually for 5 years. A total of 579 neurocognitive evaluations were included in these analyses. Results Baseline IQ and VABS were below normative means (PVABS across the follow-up period, except for the VABS Communication Index, which declined significantly (P=.015). Annual change in IQ (−.04 points) did not correlate with annual change in VABS (−.90 to +.44 points). Clinical factors associated with poorer baseline performance (P<.05) included preirradiation chemotherapy, cerebrospinal fluid shunt placement, number and extent of surgical resections, and younger age at treatment. No clinical factors significantly affected the rate of change in scores. Conclusions Conformal and intensity modulated radiation therapies provided relative sparing of functional outcomes including IQ and adaptive behaviors, even in very young children. Communication skills remained vulnerable and should be the target of preventive and rehabilitative interventions. PMID:22541967

  16. A simple scoring ratio to index the conformity of radiosurgical treatment plans. Technical note.

    Science.gov (United States)

    Paddick, I

    2000-12-01

    A conformity index is a measure of how well the volume of a radiosurgical dose distribution conforms to the size and shape of a target volume. Because the success of radiosurgery is related to the extremely conformal irradiation of the target, an accurate method for describing this parameter is important. Existing conformity ratios and indices used in radiosurgery are reviewed and criticized. It will be demonstrated that previously proposed measurements of conformity can, under certain conditions, give false perfect scores. A new conformity index is derived that gives an objective score of conformity for a treatment plan and gives no false scores. An analysis of five different treatment plans is made using both the existing scoring methods and the new conformity index.

  17. THREE-DIMENSIONAL CONFORMAL RADIATION THERAPY FOR LOCALLY RECURRENT NASOPHARYNGEAL CARCINOMA

    Institute of Scientific and Technical Information of China (English)

    ZHENG; Xiao-kang

    2001-01-01

    [1]Carlos AP, Luther WB. Carcinoma of the nasopharynx. In: Principles and Practice of Radiation Oncology [M]. 3th ed. Philadelphial: JB Lippincott, 1997; 930.[2]Yang TS, Ng KT, Wang HM, et al. Prognostic factors of locoregionally recurrent nasopharyngeal carcinoma ? a retrospective review of 182 cases [J]. Am J Clin Oncol 1996; 19:337.[3]Lee AW, Law SC, Foo W, et al. Retrospective analysis of patients with nasopharyngeal carcinoma treated during 1976-1985: survival after local recurrence [J]. Int J Radiat Oncol Biol Phys 1993; 26:773.[4]Lee AW, Poon YF, Foo W, et al. Retrospective analysis of 5037 patients with nasopharyngeal carcinoma treated during 1976-1985: overall survival and patterns of failure [J]. Int J Radiat Oncol Biol Phys 1992; 23:261.[5]Sanguineti G, Geara FB, Garden AS. Carcinoma of nasopharynx treated by radiotherapy alone: determinants of local and regional control [J]. Int J Radiat Oncol Biol Phys 1997; 37:973.[6]Lee AW, Foo W, Law SC, et al. Reirradiation for recurrent nasopharyngeal carcinoma: factors affecting the therapeutic ratio and ways for improvement [J]. Int J Radioat Oncol Biol Phys 1997; 38:43.[7]Chua DT, Sham JS, Kwong DL, et al. Locally recurrent nasopharyngeal carcinoma: treatment result for patients with computed tomography assessment [J]. Int J Radioat Oncol Biol Phys 1998; 41:379.[8]Teo PM, Kwan WH, Chan AT, et al. How successful is high-dose (>or = 60 Gy) reirradiation using mainly external beams in salvaging local failures of nasopharyngeal carcinoma [J]? Int J Radioat Oncol Biol Phys 1998; 40:897.[9]Pryzant RM, Wendt CD, Delclos L, et al. Retreatment of nasopharyngeal carcinoma in 53 patients [J]. Int J Radiat Oncol Biol Phys 1992; 22:94l.[10]Bajada C, Selch M, De SA, et al. Application of stereotactic radiosurgery to the head and neck region [J]. Acta Neurochir Suppl Wien 1994; 62:114.[11]Mitsuhashi N, Sakurai H, Katano S, et al. Stereotactic radiotherapy for locally recurrent

  18. Three-Dimensional Dose Optimization for Noncoplanar Treatment Planning with Conformal Fields.

    Science.gov (United States)

    Ma, Ying-Chang L.

    1990-01-01

    Recent advances in imaging techniques, especially three dimensional reconstruction of CT images, have made precision tumor localization feasible. These imaging techniques along with developments in computer controlled radiation treatment machines have provided an important thrust in developing better techniques for cancer treatment. This often requires a complex noncoplanar beam arrangements and elaborate treatment planning, which, unfortunately, are time consuming, costly and dependent on operator expertise and experience. A reliable operator-independent dose optimization tool is therefore desirable, especially for 3D treatment planning. In this dissertation, several approaches (linear programming, quadratic programming, and direct search methods) of computer optimization using various criteria including least sire fitting on the 90% isodose to target periphery, dose uniformity, and integral dose are presented. All of these methods are subject to restrictions on the upper limit of the dose to critical organs. In the quadratic programming approach, Kuhn-Tucker theory was employed to convert the quadratic problem into one which permits application of the very powerful, revised simplex method. Several examples are used to analyze the effectiveness of these dose optimization approaches. The studies show that the quadratic programming approach with the criteria of least square fitting and critical organ constraints is superior in efficiency for dose optimization in 3D treatment planning, particularly for cases with a large number of beams. Use of least square fitting allows one to deduce optimized plans for irregularly shaped targets by employing a multi-isocentric technique. Our studies also illustrate the advantages of using irregular conformal fields, optimized beam energy, and noncoplanar beam arrangements in contrast to the conventional treatment which uses a symmetrical rectangular collimator, fixed beam energy, and coplanar beam arrangements. Optimized plans can

  19. Preliminary study of the 270 Bloom Fricke xylenol gel phantom performance for 3D conformal radiotherapy using multiple radiation fields

    Energy Technology Data Exchange (ETDEWEB)

    Cavinato, Christianne C.; Campos, Leticia L., E-mail: ccavinato@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (DIRF/IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes; Souza, Benedito H.; Carrete Junior, Henrique; Daros, Kellen A.C.; Medeiros, Regina B. [Universidade Federal de Sao Paulo (UNIFESP), SP (Brazil). Dept. de Diagnostico por Imagens; Giordani, Adelmo J. [Universidade Federal de Sao Paulo (UNIFESP), Sao Paulo, SP (Brazil). Servico de Radioterapia

    2011-07-01

    The complex cancer treatment techniques require rigorous quality control (QC). The Fricke xylenol gel (FXG) dosimeter has been studied to be applied as a three-dimensional (3D) dosimeter since it is possible to produce 3D FXG phantoms of various shapes and sizes. In this preliminary study, the performance of the FXG spherical phantom developed at IPEN, prepared using 270 Bloom gelatin from porcine skin made in Brazil, was evaluated using magnetic resonance imaging technique, aiming to use this phantom to 3D conformal radiotherapy (3DCRT) with multiple radiation fields and clinical photon beams. The obtained results indicate that for all magnetic resonance images of the FXG phantom irradiated with 6 MV clinical photon beam can be observed clearly the target volume and, in the case of coronal image, can also be observed the radiation beam projection and the overlap of different radiation fields used. The Fricke xylenol gel phantom presented satisfactory results for 3DCRT and clinical photon beams in this preliminary study. These results encourage the additional tests using complex treatment techniques and indicate the viability of applying the phantom studied to routine quality control measurements and in 3DCRT and intensity modulated radiotherapy treatment planning. (author)

  20. Radiatively induced symmetry breaking and the conformally coupled magnetic monopole in AdS space

    CERN Document Server

    Edery, Ariel

    2013-01-01

    We implement quantum corrections for a magnetic monopole in a classically conformally invariant theory containing gravity. This yields the trace (conformal) anomaly and introduces a length scale in a natural fashion via the process of renormalization. We evaluate the one-loop effective potential and extract the vacuum expectation value (VEV) from it; spontaneous symmetry breaking is radiatively induced. The VEV is set at the renormalization scale $M$ and we exchange the dimensionless scalar coupling constant for the dimensionful VEV via dimensional transmutation. The asymptotic (background) spacetime is anti-de Sitter (AdS) and its Ricci scalar is determined entirely by the VEV. We obtain analytical asymptotic solutions to the coupled set of equations governing gravitational, gauge and scalar fields that yield the magnetic monopole in an AdS spacetime.

  1. Early radiative properties of the developments of time-symmetric conformally flat initial data

    Energy Technology Data Exchange (ETDEWEB)

    Kroon, Juan Antonio Valiente [Max Planck Institut fuer Gravitationsphysik, Albert Einstein Institut, Am Muehlenberg 1, 14476 Golm (Germany)

    2003-03-07

    Using a representation of spatial infinity based on the properties of conformal geodesics, the first terms of an expansion for the Bondi mass for the development of time-symmetric, conformally flat initial data are calculated. As is to be expected, the Bondi mass agrees with the ADM at the sets where null infinity 'touches' spatial infinity. The second term in the expansion is proportional to the sum of the squared norms of the Newman-Penrose constants of the spacetime. On the basis of this result it is argued that these constants may provide a measure of the incoming radiation contained in the spacetime. This is illustrated by means of the Misner and Brill-Lindquist datasets. (letter to the editor)

  2. Dose conformation to the spine during palliative treatments using dynamic wedges

    Energy Technology Data Exchange (ETDEWEB)

    Ormsby, Matthew A., E-mail: Matthew.Ormsby@usoncology.com [West Texas Cancer Center at Medical Center Hospital, Odessa, TX (United States); Herndon, R. Craig; Kaczor, Joseph G. [West Texas Cancer Center at Medical Center Hospital, Odessa, TX (United States)

    2013-07-01

    Radiation therapy is commonly used to alleviate pain associated with metastatic disease of the spine. Often, isodose lines are manipulated using dynamic or physical wedges to encompass the section of spine needing treatment while minimizing dose to normal tissue. We will compare 2 methods used to treat the entire thoracic spine. The first method treats the thoracic spine with a single, nonwedged posterior-anterior (PA) field. Dose is prescribed to include the entire spine. Isodose lines tightly conform to the top and bottom vertebrae, but vertebrae between these 2 received more than enough coverage. The second method uses a combination of wedges to create an isodose line that mimics the curvature of the thoracic spine. This “C”-shaped curvature is created by overlapping 2 fields with opposing dynamic wedges. Machine constraints limit the treatment length and therefore 2 isocenters are used. Each of the 2 PA fields contributes a portion of the total daily dose. This technique creates a “C”-shaped isodose line that tightly conforms to the thoracic spine, minimizing normal tissue dose. Spinal cord maximum dose is reduced, as well as mean dose to the liver, esophagus, and heart.

  3. Repulsive gravity induced by a conformally coupled scalar field implies a bouncing radiation-dominated universe

    Science.gov (United States)

    Antunes, V.; Novello, M.

    2017-04-01

    In the present work we revisit a model consisting of a scalar field with a quartic self-interaction potential non-minimally (conformally) coupled to gravity (Novello in Phys Lett 90A:347 1980). When the scalar field vacuum is in a broken symmetry state, an effective gravitational constant emerges which, in certain regimes, can lead to gravitational repulsive effects when only ordinary radiation is coupled to gravity. In this case, a bouncing universe is shown to be the only cosmological solution admissible by the field equations when the scalar field is in such broken symmetry state.

  4. Evaluation of biochemical response on early prostate cancer: comparison between treatment with external beam radiation alone and in combination with high-dose rate conformal brachytherapy boost; Avaliacao da resposta bioquimica no cancer inicial de prostata: experiencia uninstitucional comparando teleterapia exclusiva ou associada a braquiterapia de alta taxa de dose

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Douglas Guedes de; Chen, Michael Jenwei; Pellizzon, Antonio Cassio Assis; Maia, Maria Aparecida Conte; Novaes, Paulo Eduardo Ribeiro dos Santos; Fogaroli, Ricardo Cesar; Ferrigno, Robson; Salvajoli, Joao Victor [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Dept. de Radioterapia]. E-mail: dougepm@uol.com.br; Nishimoto, Ines Nobuko [Hospital do Cancer A.C. Camargo, Sao Paulo, SP (Brazil). Centro de Estudos

    2004-08-01

    Objective: To compare the biochemical response in patients with locally advanced prostate cancer treated with external beam radiation therapy alone or in combination with conformal brachytherapy boost. Materials and methods: From November 1997 to January 2000, 74 patients received 45 Gy of pelvic external irradiation and four were treated with high dose rate iridium-192 conformal boost implants of 4 Gy each (BT). These were compared with 29 other patients treated with 45 Gy of pelvic external irradiation followed by a 24 Gy of bilateral ARC boost (RT) from October 1996 to February 2000. Some patients received neoadjuvant androgen deprivation therapy. Three-year actuarial biochemical control rates (BC3) and pretreatment biochemical response predictors such as prostate-specific antigen pretreatment (PSAi), Gleason score (GS) and clinical stage (CS), were evaluated. Results: Median follow-up was of 25 months for the RT group and 37 months for the BT group. BC3 was 51% versus 73% (p = 0.032) for RT and BT, respectively. Comparisons of biochemical control by treatment group stratified by PSAi showed that BC3 for RT versus BT was 85.7% versus 79.1% (p = 0.76) for PSAi {<=}10 ng/mL and 38% versus 68% (p = 0.023) for PSAi > 10 ng/mL, respectively. For patients with GS {<=} 6, BC3 was 37% versus 80% (p = 0.001) for RT versus BT and, for patients with GS > 6, BC3 was 78% versus 55% (p = 0.58) for RT versus BT, respectively. For patients with CS {<=} T2a, BC3 was 36% versus 74% (p 0.018) for RT versus BT and, for patients with CS > T2a, BC3 was 73% versus 69% (p 0.692) for RT versus BT, respectively. The relative risk of biochemical relapse was 2.3 (95% IC: 1.0-5.1) for patients in RT group compared to the BT group. When adjusted for PSAi and GS, the relative risk of biochemical relapse was 2.4 (95% IC: 1.0-5.7). Conclusion: The treatment modality was an independent prognostic factor for biochemical relapse, with a significant improvement in the biochemical control with BT

  5. Radiation treatment and radiation reactions in dermatology. 2. ed.

    Energy Technology Data Exchange (ETDEWEB)

    Panizzon, Renato G. [Univ. Hospital CHUV, Lausanne (Switzerland). Dept. of Dermatology; Seegenschmiedt, M. Heinrich (ed.) [Strahlenzentrum Hamburg (Germany)

    2015-03-01

    Explains the use of radiation treatment in the full range of skin cancers and precancerous lesions. Covers physical and radiobiological principles, dose definitions, radiation reactions, and risk assessments. Revised and updated edition that includes new chapters and numerous additional figures. In this book, leading experts in the dermatological and oncological field describe the use of radiation therapy for the treatment of the full range of dermatological malignancies - including basal cell carcinoma, squamous cell carcinoma, cutaneous lymphomas, Kaposi's sarcoma, melanoma, and Merkel cell tumor - as well as those precancerous lesions and non-malignant dermatological disorders which are amenable to radiation therapy. In each case the specific indications for the use of radiotherapy and its application are clearly explained with the aid of numerous high-quality illustrations. In addition, the book provides a concise introduction to physical and radiobiological principles, selection of radiation factors, dose definitions, radiation reactions, and risk assessments. The new edition has been thoroughly revised and updated to reflect advances in practical knowledge and clinical practice. It will be an invaluable source of information on the management of skin tumors and related non-malignant disorders for both dermatologists, oncologists and radiation oncologists.

  6. A dose homogeneity and conformity evaluation between ViewRay and pinnacle-based linear accelerator IMRT treatment plans.

    Science.gov (United States)

    Saenz, Daniel L; Paliwal, Bhudatt R; Bayouth, John E

    2014-04-01

    ViewRay, a novel technology providing soft-tissue imaging during radiotherapy is investigated for treatment planning capabilities assessing treatment plan dose homogeneity and conformity compared with linear accelerator plans. ViewRay offers both adaptive radiotherapy and image guidance. The combination of cobalt-60 (Co-60) with 0.35 Tesla magnetic resonance imaging (MRI) allows for magnetic resonance (MR)-guided intensity-modulated radiation therapy (IMRT) delivery with multiple beams. This study investigated head and neck, lung, and prostate treatment plans to understand what is possible on ViewRay to narrow focus toward sites with optimal dosimetry. The goal is not to provide a rigorous assessment of planning capabilities, but rather a first order demonstration of ViewRay planning abilities. Images, structure sets, points, and dose from treatment plans created in Pinnacle for patients in our clinic were imported into ViewRay. The same objectives were used to assess plan quality and all critical structures were treated as similarly as possible. Homogeneity index (HI), conformity index (CI), and volume receiving conformity increase for lung. The volume receiving 20% of the prescription dose increased 2-8% for head and neck and up to 4% for lung and prostate. Overall, for head and neck Co-60 ViewRay treatments planned with its Monte Carlo treatment planning software were comparable with 6 MV plans computed with convolution superposition algorithm on Pinnacle treatment planning system.

  7. Effect of ionizing radiation on the human brain: white matter and gray matter T1 in pediatric brain tumor patients treated with conformal radiation therapy.

    Science.gov (United States)

    Steen, R G; Koury B S, M; Granja, C I; Xiong, X; Wu, S; Glass, J O; Mulhern, R K; Kun, L E; Merchant, T E

    2001-01-01

    To test a hypothesis that fractionated radiation therapy (RT) to less than 60 Gy is associated with a dose-related change in the spin-lattice relaxation time (T1) of normal brain tissue, and that such changes are detectable by quantitative MRI (qMRI). Each of 21 patients received a qMRI examination before treatment, and at several time points during and after RT. A map of brain T1 was calculated and segmented into white matter and gray matter at each time point. The RT isodose contours were then superimposed upon the T1 map, and changes in brain tissue T1 were analyzed as a function of radiation dose and time following treatment. We used a mixed-model analysis to analyze the longitudinal trend in brain T1 from the start of RT to 1 year later. Predictive factors evaluated included patient age and clinical variables, such as RT dose, time since treatment, and the use of an imaging contrast agent. In white matter (WM), a dose level of greater than 20 Gy was associated with a dose-dependent decrease in T1 over time, which became significant about 3 months following treatment. In gray matter (GM), there was no significant change in T1 over time, as a function of RT doses effect on brain T1. Results suggest that T1 mapping may be sensitive to radiation-related changes in human brain tissue T1. WM T1 appears to be unaffected by RT at doses less than approximately 20 Gy; GM T1 does not change at doses less than 60 Gy. However, tumor appears to have an effect upon adjacent GM, even before treatment. Conformal RT may offer a substantial benefit to the patient, by minimizing the volume of normal brain exposed to greater than 20 Gy.

  8. Radiation and scattering from cylindrically conformal printed antennas. Ph.D. Thesis Final Report

    Science.gov (United States)

    Kempel, Leo C.; Volakis, John L.

    1994-01-01

    Microstrip patch antennas offer considerable advantages in terms of weight, aerodynamic drag, cost, flexibility, and observables over more conventional protruding antennas. These flat patch antennas were first proposed over thirty years ago by Deschamps in the United States and Gutton and Baisinot in France. Such antennas have been analyzed and developed for planar as well as curved platforms. However, the methods used in these designs employ gross approximations, suffer from extreme computational burden, or require expensive physical experiments. The goal of this thesis is to develop accurate and efficient numerical modeling techniques which represent actual antenna structures mounted on curved surfaces with a high degree of fidelity. In this thesis, the finite element method is extended to cavity-backed conformal antenna arrays embedded in a circular, metallic, infinite cylinder. Both the boundary integral and absorbing boundary mesh closure conditions will be used for terminating the mesh. These two approaches will be contrasted and used to study the scattering and radiation behavior of several useful antenna configurations. An important feature of this study will be to examine the effect of curvature and cavity size on the scattering and radiation properties of wraparound conformal antenna arrays.

  9. Revised standards for protection against radiation; minor amendments--NRC. Final rule: minor corrective and conforming amendments.

    Science.gov (United States)

    1992-12-01

    This final rule makes a number of minor corrective and conforming amendments to the NRC's revised standards for protection against radiation. The final rule is necessary to correct recently discovered errors in the text of the revised standards, to conform portions of regulatory text to the Commission's decision to defer mandatory implementation of the revised standards until 1994, and to reflect the recent OMB approval of the use of NRC Forms 4 and 5.

  10. Cellulose destruction under successive thermal and radiation treatment. [Gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Ershov, B.G.; Komarov, V.B.

    1985-02-01

    The influence of successive thermal and radiation effect on cellulose is investigated. The samples were ..gamma.. irradiated (/sup 60/Co) with a dose rate of 20 kGy/h (the absorbed doses ranged from 0 to 80 kGy) and heated up to 190 deg C. It is shown that the attainment of the same destruction depth for the heated-up cellulose occurs at noticeably lower absorbed doses than for the cellulose which has not been subjected to thermal treatment. For successive thermal and radiation treatment of cellulose the ratio S=S therm.+Ssub(rad) where S is a number of broken bonds in a macromolecule is correct. The radiation-chemical yield of cellulose destruction is determined to be: G=7.3 +- 0.1 mol/100 eV.

  11. Erectile dysfunction after prostate three-dimensional conformal radiation therapy. Correlation with the dose to the penile bulb

    Energy Technology Data Exchange (ETDEWEB)

    Magli, A.; Ceschia, T.; Titone, F.; Parisi, G.; Fongione, S. [University Hospital Udine (Italy). Dept. of Radiation Oncology; Giangreco, M. [Udine Univ. (Italy). Hygiene and Epidemiology Inst.; Crespi, M.; Negri, A. [University Hospital Udine (Italy). Dept. of Medical Physics; De Giorgi, G. [University Hospital Udine (Italy). Dept. of Urology

    2012-11-15

    Purpose: Erectile dysfunction is associated with all the common treatment options for prostate cancer. The aim of this research was to evaluate the relationship between erectile function and radiation dose to the penile bulb (PB) and other proximal penile structures in men receiving conformal radiotherapy (CRT) without hormonal therapy (HT) for prostate cancer, whose sexual function was known before treatment. Patients and methods: The study included 19 patients treated with 3D-CRT for localized prostate cancer at our department, who were self-reported to be potent before treatment, had not received HT, and had complete follow-up data available. Our evaluation was based on the International Index of Erectile Function (IIEF-5). Dose-volume histograms (DVHs) were used to evaluate the dose to the PB. Statistical analysis was performed with an unconditional logistic regression model. Results: All patients reported change in potency after radiation. Eight patients (42%) remained potent but showed a decrease of 1 or 2 levels of potency, as defined by the IIEF-5 questionnaire (reduced potency group), while 11 patients (58%) reported a change of higher levels and revealed a severe erectile dysfunction after 2 years (impotence group). Multivariate analysis of morphological and dosimetric variables yielded significance for the mean dose (p = 0.05 with an odds ratio of 1.14 and 95% CI 1-1.30). Patients receiving a mean dose of less than 50 Gy to the PB appear to have a much greater likelihood of maintaining potency. Conclusion: Our data suggest a possible existence of a dose-volume correlation between the dose applied to the PB and radiation-induced impotence. (orig.)

  12. Comparative outcomes for three-dimensional conformal versus intensity-modulated radiation therapy for esophageal cancer.

    Science.gov (United States)

    Freilich, J; Hoffe, S E; Almhanna, K; Dinwoodie, W; Yue, B; Fulp, W; Meredith, K L; Shridhar, R

    2015-01-01

    Emerging data suggests a benefit for using intensity modulated radiation therapy (IMRT) for the management of esophageal cancer. We retrospectively reviewed patients treated at our institution who received definitive or preoperative chemoradiation with either IMRT or 3D conformal radiation therapy (3DCRT) between October 2000 and January 2012. Kaplan Meier analysis and the Cox proportional hazard model were used to evaluate survival outcomes. We evaluated a total of 232 patients (138 IMRT, 94 3DCRT) who received a median dose of 50.4 Gy (range, 44-64.8) to gross disease. Median follow up for all patients, IMRT patients alone, and 3DCRT patients alone was 18.5 (range, 2.5-124.2), 16.5 (range, 3-59), and 25.9 months (range, 2.5-124.2), respectively. We observed no significant difference based on radiation technique (3DCRT vs. IMRT) with respect to median overall survival (OS) (median 29 vs. 32 months; P = 0.74) or median relapse free survival (median 20 vs. 25 months; P = 0.66). On multivariable analysis (MVA), surgical resection resulted in improved OS (HR 0.444; P 20% weight loss (OR 0.51; P = 0.050). Our data suggest that while IMRT-based chemoradiation for esophageal cancer does not impact survival there was significantly less toxicity. In the IMRT group there was significant decrease in weight loss and grade ≥3 toxicity compared to 3DCRT.

  13. Pelvic radiation disease: Updates on treatment options

    Science.gov (United States)

    Frazzoni, Leonardo; La Marca, Marina; Guido, Alessandra; Morganti, Alessio Giuseppe; Bazzoli, Franco; Fuccio, Lorenzo

    2015-01-01

    Pelvic cancers are among the most frequently diagnosed neoplasms and radiotherapy represents one of the main treatment options. The irradiation field usually encompasses healthy intestinal tissue, especially of distal large bowel, thus inducing gastrointestinal (GI) radiation-induced toxicity. Indeed, up to half of radiation-treated patients say that their quality of life is affected by GI symptoms (e.g., rectal bleeding, diarrhoea). The constellation of GI symptoms - from transient to long-term, from mild to very severe - experienced by patients who underwent radiation treatment for a pelvic tumor have been comprised in the definition of pelvic radiation disease (PRD). A correct and evidence-based therapeutic approach of patients experiencing GI radiation-induced toxicity is mandatory. Therapeutic non-surgical strategies for PRD can be summarized in two broad categories, i.e., medical and endoscopic. Of note, most of the studies have investigated the management of radiation-induced rectal bleeding. Patients with clinically significant bleeding (i.e., causing chronic anemia) should firstly be considered for medical management (i.e., sucralfate enemas, metronidazole and hyperbaric oxygen); in case of failure, endoscopic treatment should be implemented. This latter should be considered the first choice in case of acute, transfusion requiring, bleeding. More well-performed, high quality studies should be performed, especially the role of medical treatments should be better investigated as well as the comparative studies between endoscopic and hyperbaric oxygen treatments. PMID:26677440

  14. Two-Year and Lifetime Cost-Effectiveness of Intensity Modulated Radiation Therapy Versus 3-Dimensional Conformal Radiation Therapy for Head-and-Neck Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Kohler, Racquel E. [Department of Health Policy and Management, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (United States); Sheets, Nathan C. [Department of Radiation Oncology, University of North Carolina Hospitals, Chapel Hill, North Carolina (United States); Wheeler, Stephanie B. [Department of Health Policy and Management, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina (United States); Nutting, Chris [Royal Marsden Hospital, London, United Kindom (United Kingdom); Hall, Emma [Clinical Trials and Statistics Unit, Division of Clinical Studies, Institute of Cancer Research, London (United Kingdom); Chera, Bhishamjit S., E-mail: bchera@med.unc.edu [Department of Radiation Oncology, University of North Carolina Hospitals, Chapel Hill, North Carolina (United States)

    2013-11-15

    Purpose: To assess the cost-effectiveness of intensity modulated radiation therapy (IMRT) versus 3-dimensional conformal radiation therapy (3D-CRT) in the treatment of head-and neck-cancer (HNC). Methods and Materials: We used a Markov model to simulate radiation therapy-induced xerostomia and dysphagia in a hypothetical cohort of 65-year-old HNC patients. Model input parameters were derived from PARSPORT (CRUK/03/005) patient-level trial data and quality-of-life and Medicare cost data from published literature. We calculated average incremental cost-effectiveness ratios (ICERs) from the US health care perspective as cost per quality-adjusted life-year (QALY) gained and compared our ICERs with current cost-effectiveness standards whereby treatment comparators less than $50,000 per QALY gained are considered cost-effective. Results: In the first 2 years after initial treatment, IMRT is not cost-effective compared with 3D-CRT, given an average ICER of $101,100 per QALY gained. However, over 15 years (remaining lifetime on the basis of average life expectancy of a 65-year-old), IMRT is more cost-effective at $34,523 per QALY gained. Conclusion: Although HNC patients receiving IMRT will likely experience reduced xerostomia and dysphagia symptoms, the small quality-of-life benefit associated with IMRT is not cost-effective in the short term but may be cost-effective over a patient's lifetime, assuming benefits persist over time and patients are healthy and likely to live for a sustained period. Additional data quantifying the long-term benefits of IMRT, however, are needed.

  15. Clinical observation of low-dose domestic type for S-1 capsules combined with three dimentional conformal radiation in the treatment of aged patients with cardiac cancer%低剂量国产替吉奥胶囊联合三维适型放疗治疗老年贲门癌

    Institute of Scientific and Technical Information of China (English)

    王刚; 陈公安; 刘旭; 苗旺; 朱眉

    2015-01-01

    Objective To observe the curative effect and safety of the domestic type for S-1 capsule combined the three-dimensional conformal radiotherapy (3-DCT) in the treatment of aged patients with cardiac cancer.Methods Forty-six elderly patients with cardia cancer were studied from January 2009 to September 2011.After ruling out the contraindications of chemotherapy and radiotherapy,the patients were given oral chemotherapy with the domestic S-1 capsules (Weikangda),40 mg,2 times/day,d1-14,21 days for one circle,combined with synchronous three dimentional conformal radiation on local primay lessions and metastatic nudes.It' s dose was 1.8 Gy/time,five times a week,DT 39.6-54 Gy.It took 4-5.5 weeks to complete the radiation,following with a total 3-6 cycles of chemotherapy.The gastrointestinal side effects and bone marrow suppression were observed,and the treatment tolerance were researched during the treatment.The recent curative effect and follow-up of 1,2 year survival rate were studied.Results The patients' digestive tract symptoms were improved after radiation over 2 months and 4 months.The objective response rate (CR + PR) was 82.6%,1 year survival rate was 84.7% and 2 year survival rate was 65.2%.Conclusions The domestic type for S-1 capsule combined the three-dimensional conformal radiotherapy (3-DCT) in the treatment of aged patients with cardiac cancer is practicable and safe,the clinical currative effect is better and the further clinical research is recommend.%目的 观察国产替吉奥胶囊联合三维适型放疗治疗老年责门癌的疗效及安全性.方法 2009年1月至2011年9月收治46例老年贲门癌患者,排除放化疗禁忌证后,第1周期化疗开始口服国产替吉奥胶囊(维康达)40 mg,2次/d,第1~14天,21 d为1个周期,同步贲门原发病灶及周围淋巴结行三维适型放疗,1.8 Gy/次,每周5次,DT39.6 ~ 54.0 Gy,4~5.5周完成放疗,继续完成共3~6个周期的化疗.治疗过程中观察患者的消化

  16. A dosimetric comparative study between conformal and intensity modulated radiation therapy in the treatment of primary nasopharyngeal carcinomas: the Egyptian experience%三维适形放疗和调强放疗治疗原发性鼻咽癌的剂量学对比研究:来自埃及的经验报道

    Institute of Scientific and Technical Information of China (English)

    Ehsan G. El-Ghoneimy; Mohamed A. Hassan; Mahmoud F. El-Bestar; Omar M. Othman; Karim N. Mashhour

    2012-01-01

    Objective: The study is a comparative study, the aim of which is to compare 3D conformal radiation therapy (3D-CRT) and intensity modulated radiation therapy (IMRT) in treating nasopharyngeal carcinomas; dosimetrically evaluating and comparing both techniques as regard target coverage and doses to organs at risk (OAR). Methods: Twenty patients with nasopharyngeal carcinoma were treated by 3D-CRT technique and another 20 patients were treated by IMRT. A dosimetric comparison was done by performing two plans for the same patient using Eclipse planning system (version 8.6). Results: IMRT had a better tumor coverage and conformity index compared to 3D-CRT plans (P value of 0.001 and 0.004), respectively. As for the dose homogeneity it was also better in the IMRT plans and the reason for this was attributed to the dose inhomogeneity at the photon/electron junction in the 3D-CRT plans (P value 0.032). Also, doses received by the risk structures, particularly parotids, was significantly less in the IMRT plans than those of 3D-CRT (P value 0.001). Conclusion: IMRT technique was clearly able to increase the dose delivery to the target volume, improve conformity and homogeneity index and spare the parotid glands in comparison to 3D-CRT technique.

  17. Radiation treatment of ovarian cancer

    Energy Technology Data Exchange (ETDEWEB)

    Morita, S.; Arai, T.; Kurisu, A. (National Inst. of Radiological Sciences, Chiba (Japan))

    1982-03-01

    We evaluated the clinical results obtained in 129 primary malignant ovarian cancer patients who had been treated by 4 modes of postoperative irradiation between 1961 and 1980 at NIRS. The 3- and 5-year survival rates were 52% (45/86) and 43% (32/75) in total and 71% (20/28) and 59% (10/17) in whole abdominal irradiation cases, respectively. Leucopenia (>2,000) occurred in 48%, ileus in 5.2% of the latter cases. The necessity of combining radiation therapy with surgery and chemotherapy was emphasized.

  18. Classically conformal radiative neutrino model with gauged B−L symmetry

    Directory of Open Access Journals (Sweden)

    Hiroshi Okada

    2016-09-01

    Full Text Available We propose a classically conformal model in a minimal radiative seesaw, in which we employ a gauged B−L symmetry in the standard model that is essential in order to work the Coleman–Weinberg mechanism well that induces the B−L symmetry breaking. As a result, nonzero Majorana mass term and electroweak symmetry breaking simultaneously occur. In this framework, we show a benchmark point to satisfy several theoretical and experimental constraints. Here theoretical constraints represent inert conditions and Coleman–Weinberg condition. Experimental bounds come from lepton flavor violations (especially μ→eγ, the current bound on the Z′ mass at the CERN Large Hadron Collider, and neutrino oscillations.

  19. Invariant classification and the generalised invariant formalism: conformally flat pure radiation metrics, with zero cosmological constant

    CERN Document Server

    Bradley, Michael; Ramos, M P Machado

    2008-01-01

    Metrics obtained by integrating within the generalised invariant formalism are structured around their intrinsic coordinates, and this considerably simplifies their invariant classification and symmetry analysis. We illustrate this by presenting a simple and transparent complete invariant classification of the conformally flat pure radiation metrics (except plane waves) in such intrinsic coordinates; in particular we confirm that the three apparently non-redundant functions of one variable are genuinely non-redundant, and easily identify the subclasses which admit a Killing and/or a homothetic Killing vector. Most of our results agree with the earlier classification carried out by Skea in the different Koutras-McIntosh coordinates, which required much more involved calculations; but there are some subtle differences. Therefore, we also rework the classification in the Koutras-McIntosh coordinates, and by paying attention to some of the subtleties involving arbitrary functions, we are able to obtain complete a...

  20. Hyperbaric oxygen treatment for haemorrhagic radiation cystitis

    Energy Technology Data Exchange (ETDEWEB)

    Bevers, R.F.M.; Kurth, K.H. [Amsterdam Univ. (Netherlands). Academic Medical Center; Bakker, D.J. [Amsterdam Univ. (Netherlands). Depts. of Urology and Surgery

    1995-09-23

    Radiation-induced severe haemorrhagic cystitis is difficult to treat. Conventional treatments may decrease haematuria but do not affect the radiocystitis itself. Hyperbaric oxygen treatment has been reported to do both. We report the results of a prospective study of hyperbaric oxygen (20 sessions of 100% oxygen inhalation at 3 bar for 90 min in a multiplace hyperbaric chamber) to 40 patients with biopsy-proven radiation cystitis and severe haematuria. Haematuria disappeared completely or improved in 37 patients after treatment. Mean follow-up was 23.1 months (range 1-74); and the recurrence rate was 0.12/year. There were no adverse effects. Hyperbaric oxygen treatment should be considered for patients with severe radiation-induced haematuria. (author).

  1. Involved-Site Image-Guided Intensity Modulated Versus 3D Conformal Radiation Therapy in Early Stage Supradiaphragmatic Hodgkin Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Filippi, Andrea Riccardo, E-mail: andreariccardo.filippi@unito.it [Department of Oncology, University of Torino, Torino (Italy); Ciammella, Patrizia [Radiation Therapy Unit, Department of Oncology and Advanced Technology, ASMN Hospital IRCCS, Reggio Emilia (Italy); Piva, Cristina; Ragona, Riccardo [Department of Oncology, University of Torino, Torino (Italy); Botto, Barbara [Hematology, Città della Salute e della Scienza, Torino (Italy); Gavarotti, Paolo [Hematology, University of Torino and Città della Salute e della Scienza, Torino (Italy); Merli, Francesco [Hematology Unit, ASMN Hospital IRCCS, Reggio Emilia (Italy); Vitolo, Umberto [Hematology, Città della Salute e della Scienza, Torino (Italy); Iotti, Cinzia [Radiation Therapy Unit, Department of Oncology and Advanced Technology, ASMN Hospital IRCCS, Reggio Emilia (Italy); Ricardi, Umberto [Department of Oncology, University of Torino, Torino (Italy)

    2014-06-01

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows for margin reduction and highly conformal dose distribution, with consistent advantages in sparing of normal tissues. The purpose of this retrospective study was to compare involved-site IG-IMRT with involved-site 3D conformal RT (3D-CRT) in the treatment of early stage Hodgkin lymphoma (HL) involving the mediastinum, with efficacy and toxicity as primary clinical endpoints. Methods and Materials: We analyzed 90 stage IIA HL patients treated with either involved-site 3D-CRT or IG-IMRT between 2005 and 2012 in 2 different institutions. Inclusion criteria were favorable or unfavorable disease (according to European Organization for Research and Treatment of Cancer criteria), complete response after 3 to 4 cycles of an adriamycin- bleomycin-vinblastine-dacarbazine (ABVD) regimen plus 30 Gy as total radiation dose. Exclusion criteria were chemotherapy other than ABVD, partial response after ABVD, total radiation dose other than 30 Gy. Clinical endpoints were relapse-free survival (RFS) and acute toxicity. Results: Forty-nine patients were treated with 3D-CRT (54.4%) and 41 with IG-IMRT (45.6%). Median follow-up time was 54.2 months for 3D-CRT and 24.1 months for IG-IMRT. No differences in RFS were observed between the 2 groups, with 1 relapse each. Three-year RFS was 98.7% for 3D-CRT and 100% for IG-IMRT. Grade 2 toxicity events, mainly mucositis, were recorded in 32.7% of 3D-CRT patients (16 of 49) and in 9.8% of IG-IMRT patients (4 of 41). IG-IMRT was significantly associated with a lower incidence of grade 2 acute toxicity (P=.043). Conclusions: RFS rates at 3 years were extremely high in both groups, albeit the median follow-up time is different. Acute tolerance profiles were better for IG-IMRT than for 3D-CRT. Our preliminary results support the clinical safety and efficacy of advanced RT planning and delivery techniques in patients affected with early stage HL, achieving complete

  2. Investigation of conformal and intensity-modulated radiation therapy techniques to determine the absorbed fetal dose in pregnant patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Öğretici, Akın, E-mail: akinogretici@gmail.com; Akbaş, Uğur; Köksal, Canan; Bilge, Hatice

    2016-07-01

    The aim of this research was to investigate the fetal doses of pregnant patients undergoing conformal radiotherapy or intensity-modulated radiation therapy (IMRT) for breast cancers. An Alderson Rando phantom was chosen to simulate a pregnant patient with breast cancer who is receiving radiation therapy. This phantom was irradiated using the Varian Clinac DBX 600 system (Varian Medical System, Palo Alto, CA) linear accelerator, according to the standard treatment plans of both three-dimensional conformal radiation therapy (3-D CRT) and IMRT techniques. Thermoluminescent dosimeters were used to measure the irradiated phantom's virtually designated uterus area. Thermoluminescent dosimeter measurements (in the phantom) revealed that the mean cumulative fetal dose for 3-D CRT is 1.39 cGy and for IMRT it is 8.48 cGy, for a pregnant breast cancer woman who received radiation treatment of 50 Gy. The fetal dose was confirmed to increase by 70% for 3-D CRT and 40% for IMRT, if it is closer to the irradiated field by 5 cm. The mean fetal dose from 3-D CRT is 1.39 cGy and IMRT is 8.48 cGy, consistent with theoretic calculations. The IMRT technique causes the fetal dose to be 5 times more than that of 3-D CRT. Theoretic knowledge concerning the increase in the peripheral doses as the measurements approached the beam was also practically proven.

  3. Spine stereotactic body radiation therapy plans: Achieving dose coverage, conformity, and dose falloff

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Linda X., E-mail: lhong0812@gmail.com [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Shankar, Viswanathan [Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY (United States); Shen, Jin [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Kuo, Hsiang-Chi [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Mynampati, Dinesh [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Yaparpalvi, Ravindra [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States); Goddard, Lee [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Basavatia, Amar; Fox, Jana; Garg, Madhur; Kalnicki, Shalom; Tomé, Wolfgang A. [Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY (United States); Department of Radiation Oncology, Albert Einstein College of Medicine, Bronx, NY (United States)

    2015-10-01

    We report our experience of establishing planning objectives to achieve dose coverage, conformity, and dose falloff for spine stereotactic body radiation therapy (SBRT) plans. Patients with spine lesions were treated using SBRT in our institution since September 2009. Since September 2011, we established the following planning objectives for our SBRT spine plans in addition to the cord dose constraints: (1) dose coverage—prescription dose (PD) to cover at least 95% planning target volume (PTV) and 90% PD to cover at least 99% PTV; (2) conformity index (CI)—ratio of prescription isodose volume (PIV) to the PTV < 1.2; (3) dose falloff—ratio of 50% PIV to the PTV (R{sub 50%}); (4) and maximum dose in percentage of PD at 2 cm from PTV in any direction (D{sub 2cm}) to follow Radiation Therapy Oncology Group (RTOG) 0915. We have retrospectively reviewed 66 separate spine lesions treated between September 2009 and December 2012 (31 treated before September 2011 [group 1] and 35 treated after [group 2]). The χ{sup 2} test was used to examine the difference in parameters between groups. The PTV V{sub 100%} {sub PD} ≥ 95% objective was met in 29.0% of group 1 vs 91.4% of group 2 (p < 0.01) plans. The PTV V{sub 90%} {sub PD} ≥ 99% objective was met in 38.7% of group 1 vs 88.6% of group 2 (p < 0.01) plans. Overall, 4 plans in group 1 had CI > 1.2 vs none in group 2 (p = 0.04). For D{sub 2cm}, 48.3% plans yielded a minor violation of the objectives and 16.1% a major violation for group 1, whereas 17.1% exhibited a minor violation and 2.9% a major violation for group 2 (p < 0.01). Spine SBRT plans can be improved on dose coverage, conformity, and dose falloff employing a combination of RTOG spine and lung SBRT protocol planning objectives.

  4. Observation of the effect of three-dimensional conformal radiation dose fractionation treatment of advanced non-small cell lung cancer%三维适形放疗不同剂量分割治疗晚期非小细胞肺癌疗效观察

    Institute of Scientific and Technical Information of China (English)

    高宗毅; 贾立娟; 刘永利; 刘江涛; 贾彦丽

    2012-01-01

    目的 探讨三维适形放射不同剂量分割治疗晚期非小细胞肺癌( NSCLC)的近期疗效.方法 148例NSCLC随机采用三维适形放疗(3DCRT)(观察组,75例)和常规分割照射治疗(对照组,73例),观察近期疗效和不良反应,随访患者治疗后1、2、3年生存情况.结果 对照组总有效47例(64.4%),观察组总有效60例(80.0%),两组差异有统计学意义(x2=4.50,P<0.05).对照组1、2、3年生存率为50.7%、24.7%、8.2%,中位生存期为13个月;观察组分别为73.3%、45.3%、20.0%,中位生存期为19个月.两组生存率差异有统计学意义(x2=8.07、6,94、4.22,均P<0.05).观察组血液系统副反应发生率明显低于对照组(x2=4.73,P<0.05),两组急性放射性肺炎、放射性食管炎发生率差异无统计学意义(P>0.05).结论 3 DC RT对晚期NSCLC近期疗效好,且治疗不良反应低,值得在临床上推广应用.%Objective To explore the effect of three-dimensional conformal radiation dose fractionation treatment of advanced non-small cell lung cancer(NSCLC).Methods 75 NSCLC patients were treated with hypofractionated 3DCRT( observation group),while 73 cases were treated with conventional fractionated radiotherapy (control group).The efficacy and adverse reactions were observed;Survival after treatment were followed up in 1,2,3 years.Lung function was detected before and after radiotherapy treatment,including FVC,FEV1 and CLCO.Results The total effective cases of control group were 47 cases patients ( 64.4% ),observation group's was 60 cases ( 80.0% ),total effective rate had statistically significant difference ( x2 =4.50,P < 0.05 ).Survival of control group after treatment in 1,2,3year were 50.7%,24.7%,8.2%,the median survival was 13 months,observation group's were 73.3%,45.3%,20.0%,and 19 months.The survival of these two groups was statistically different (x2 =8.07,6,94,4.22,all P < 0.05 ).The patients blood system side effects of

  5. Radiation treatment of superior sulcus lung carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Millar, J.; Ball, D.; Worotniuk, V.; Smith, J.; Crennan, E.; Bishop, M. [Peter MacCallum Cancer Inst., East Melbourne, VIC (Australia)

    1996-02-01

    The survival of patients with superior sulcus lung carcinoma and the effects of treatment were reviewed. From a prospective database of 4123 consecutive new patients with lung carcinoma, 131 (3.2%) cases of superior sulcus lung carcinoma were identified. Seventy-four patients were planned to receive radiation with palliative intent, 53 radical radiotherapy and one was observed only. The remaining three patients, with small-cell carcinoma, were treated with chemotherapy with or without radiotherapy. Of the 53 radically treated patients, nine were treated with pre-operative radiation prior to intended radical resection. Analysis was carried out on the effect on survival of performance status, nodal involvement, weight loss, vertebral body or rib involvement, treatment intent and radical combined modality treatment compared with radical radiation alone. The estimated median survival for the whole group was 7.6 months; for those treated radically it was 18.3 months, while for the palliatively treated patients it was 3.7 months. Radically treated patients with no initial nodal involvement had an estimated median survival of 22 months, while radically treated patients with nodal involvement had an estimated median survival of 8.4 months (P = 0.003). There were no statistically significant differences in survival between radically treated patients grouped according to initial weight loss, performance status, or vertebral body and rib involvement. Patients treated with pre-operative radiation did not survive significantly longer than patients treated with radiation alone, although the numbers are small. 33 refs., 2 tabs., 4 figs.

  6. Characterisation of Conformational and Ligand Binding Properties of Membrane Proteins Using Synchrotron Radiation Circular Dichroism (SRCD).

    Science.gov (United States)

    Hussain, Rohanah; Siligardi, Giuliano

    Membrane proteins are notoriously difficult to crystallise for use in X-ray crystallographic structural determination, or too complex for NMR structural studies. Circular dichroism (CD) is a fast and relatively easy spectroscopic technique to study protein conformational behaviour in solution. The advantage of synchrotron radiation circular dichroism (SRCD) measured with synchrotron beamlines compared to the CD from benchtop instruments is the extended spectral far-UV region that increases the accuracy of secondary structure estimations, in particular under high ionic strength conditions. Membrane proteins are often available in small quantities, and for this SRCD measured at the Diamond B23 beamline has successfully facilitated molecular recognition studies. This was done by probing the local tertiary structure of aromatic amino acid residues upon addition of chiral or non-chiral ligands using long pathlength cells (1-5 cm) of small volume capacity (70 μl-350 μl). In this chapter we describe the use of SRCD to qualitatively and quantitatively screen ligand binding interactions (exemplified by Sbma, Ace1 and FsrC proteins); to distinguish between functionally similar drugs that exhibit different mechanisms of action towards membrane proteins (exemplified by FsrC); and to identify suitable detergent conditions to observe membrane protein-ligand interactions using stabilised proteins (exemplified by inositol transporters) as well as the stability of membrane proteins (exemplified by GalP, Ace1). The importance of the in solution characterisation of the conformational behaviour and ligand binding properties of proteins in both far- andnear-UV regions and the use of high-throughput CD (HT-CD) using 96- and 384-well multiplates to study the folding effects in various protein crystallisation buffers are also discussed.

  7. Target volume delineation and field setup. A practical guide for conformal and intensity-modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Nancy Y. [Memorial Sloan-Kettering Cancer Center, New York, NY (United States). Radiation Oncology; Lu, Jiade J. (eds.) [National Univ. Health System, Singapore (Singapore). Dept. of Radiation Oncology; National Univ. of Singapore (Singapore). Dept. of Medicine

    2013-03-01

    Practical handbook on selection and delineation of tumor volumes and fields for conformal radiation therapy, including IMRT. Helpful format facilitating use on a step-by-step basis in daily practice. Designed to ensure accurate coverage of commonly encountered tumors along their routes of spread. This handbook is designed to enable radiation oncologists to appropriately and confidently delineate tumor volumes/fields for conformal radiation therapy, including intensity-modulated radiation therapy (IMRT), in patients with commonly encountered cancers. The orientation of this handbook is entirely practical, in that the focus is on the illustration of clinical target volume (CTV) delineation for each major malignancy. Each chapter provides guidelines and concise knowledge on CTV selection for a particular disease, explains how the anatomy of lymphatic drainage shapes the selection of the target volume, and presents detailed illustrations of volumes, slice by slice, on planning CT images. While the emphasis is on target volume delineation for three-dimensional conformal therapy and IMRT, information is also provided on conventional radiation therapy field setup and planning for certain malignancies for which IMRT is not currently suitable.

  8. Development of Radiation Technique for Environmental Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myun Joo; Kuk, Il Hiun; Jin, Joon Ha (and others)

    2007-02-15

    The purpose of this research is to development of technologies for 1) the removal of toxic organic chemicals in sewage sludges and the volume reduction of the sewage sludge 2) the recycling/reuse of sewage sludge 3) the reconvey of resource from fishery waste by using radiation technologies. This research project focused on the study of treatment, disposal, and recycling/reuse of sewage sludge by radiation technology, and recovery of highly value-added resources from the wastes. As basic studies with a radiation technology, an enhancement of dewaterbilities of sewage sludge, development of dewatering conditioner, reduction of trace toxic organic chemicals, and the toxicities of the byproducts were studied. Based on the basic experimental results, we developed the pilot-scale system with the continuous e-beam and dewatering unit and the advanced treatment system with the use of carbon source recovered from sewage sludge.

  9. Classification and treatment of radiation maculopathy.

    LENUS (Irish Health Repository)

    Horgan, Noel

    2012-02-01

    PURPOSE OF REVIEW: Radiation maculopathy is a sight-limiting consequence of radiotherapy in the management of uveal melanoma and other intraocular tumors. In this review, we consider clinical, fluorescein angiographic and optical coherence tomographic findings, propose a classification for radiation maculopathy and discuss the management of this condition. RECENT FINDINGS: Radiation macular edema (RME) can be classified by optical coherence tomography into noncystoid or cystoid edema, with foveolar or extrafoveolar involvement. Optical coherence tomographic grading of RME has been found to correlate with visual acuity. Focal argon laser might have some limited benefit in the treatment of RME. Intravitreal triamcinolone and intravitreal antivascular endothelial growth factor agents can be of short-term benefit in the treatment of RME. In a randomized controlled trial, periocular triamcinolone significantly reduced rates of RME and vision loss up to 18 months following plaque radiotherapy for uveal melanoma. SUMMARY: Currently, there is no proven treatment for established RME, though periocular triamcinolone has been shown to have a preventive benefit. An accepted classification system for radiation maculopathy would be of benefit in planning and comparing future treatment trials.

  10. Comparison of acute and subacute genitourinary and gastrointestinal adverse events of radiotherapy for prostate cancer using intensity-modulated radiation therapy, three-dimensional conformal radiation therapy, permanent implant brachytherapy and high-dose-rate brachytherapy

    NARCIS (Netherlands)

    Morimoto, Masahiro; Yoshioka, Yasuo; Konishi, Koji; Isohashi, Fumiaki; Takahashi, Yutaka; Ogata, Toshiyuki; Koizumi, Masahiko; Teshima, Teruki; Bijl, Henk P; van der Schaaf, Arjen; Langendijk, Johannes A; Ogawa, Kazuhiko

    2014-01-01

    AIMS AND BACKGROUND: To examine acute and subacute urinary and rectal toxicity in patients with localized prostate cancer monotherapeutically treated with the following four radiotherapeutic techniques: intensity-modulated radiation therapy, three-dimensional conformal radiation therapy,

  11. Radiation therapy for localized prostate cancer. For high-dose rate conformal brachytherapy

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Keigo; Jo, Yoshimasa; Morioka, Masaaki; Tanaka, Hiroyoshi; Hiratsuka, Junichi; Imajo, Yoshinari [Kawasaki Medical School, Kurashiki, Okayama (Japan)

    1999-05-01

    Sixteen patients with localized prostate cancer were referred to our clinic for radiation therapy in combination with HDR brachytherapy using Ir-192 pellets between October 1997 and August 1998. The patients were given external beam radiation of 45 Gy to the whole pelvis in combination with an interstitial HDR brachytherapy implant of 3 fractions each delivering 5.5 Gy during two days. Using an implanting device especially designed for HDR, 10-18 applicator needles (17 gauge) were implanted into the prostate using transrectal ultrasound (TRUS) with perineal template guidance under spinal anesthesia. Pathological evaluation was performed at 6 months after treatment. This technique of external beam radiation combined with HDR brachytherapy was well tolerated. Serum prostatic antigen (PSA) levels became normalized in 87.5% of the patients (14 out of 16) within 1-14 months (median 2 months) after the irradiation. No significant intraoperative or perioperative complications occurred, however one patient (6.25%) experienced Grade 3 hematuria. Most of the early complications were otherwise Grade 1 or 2. From prospectively planned prostatic rebiopsies performed at 6 months, we can observe the radiation effects in the pathological findings such as fibrosis, basal cell hyperplasia, bizarre cells and intraductal calcifications. (K.H.)

  12. Dosimetric effect on pediatric conformal treatment plans using dynamic jaw with Tomotherapy HDA

    Energy Technology Data Exchange (ETDEWEB)

    Han, Eun Young, E-mail: eyhan@uams.edu [Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR (United States); Kim, Dong-Wook [Department of Radiation Oncology, Kyung Hee University Hospital, Seoul (Korea, Republic of); Zhang, Xin; Penagaricano, Jose; Liang, Xiaoying; Hardee, Matthew; Morrill, Steve; Ratanatharathorn, Vaneerat [Department of Radiation Oncology, University of Arkansas Medical Sciences, Little Rock, AR (United States)

    2015-10-01

    It is important to minimize the radiation dose delivered to healthy tissues in pediatric cancer treatment because of the risk of secondary malignancies. Tomotherapy HDA provides a dynamic jaw (DJ) delivery mode that creates a sharper penumbra at the craniocaudal ends of a target in addition to a fixed jaw (FJ) delivery mode. The purpose of this study was to evaluate its dosimetric effect on the pediatric cancer cases. We included 6 pediatric cases in this study. The dose profiles and plan statistics—target dose conformity, uniformity, organ-at-risk (OAR) mean dose, beam-on time, and integral dose—were compared for each case. Consequently, the target dose coverage and uniformity were similar for different jaw settings. The OAR dose sparing depended on its relative location to the target and disease sites. For example, in the head and neck cancer cases, the brain stem dose using DJ 2.5 was reduced by more than two-fold (2.4 Gy vs. 6.3 Gy) than that obtained with FJ 2.5. The integral dose with DJ 2.5 decreased by more than 9% compared with that with FJ 2.5. Thus, using dynamic jaw in pediatric cases could be critical to reduce a probability of a secondary malignancy.

  13. Treatment of radiation enteritis: a comparison study

    Energy Technology Data Exchange (ETDEWEB)

    Loiudice, T.A.; Lang, J.A.

    1983-08-01

    Twenty-four patients with severe radiation injury to the small bowel seen over a 4-year period were randomized to four treatment groups: 1) methylprednisolone 80 mg intravenously plus Vivonex-HN, 2 L/day po, 2) methylprednisolone 80 mg intravenously plus total parenteral nutrition, 2.5 L/day, 3) total parenteral nutrition, 2.5 L/day, and 4) Vivonex-HN, 2 L/day po. Patients received nothing by mouth except water in groups II and III, and only Vivonex-HN in groups I and IV. Patients were treated for 8-wk periods. Improvement was gauged by overall nutritional assessment measurements, nitrogen balance data and by radiological and clinical parameters. No significant difference between groups I, II, III, and IV could be found for age, sex, mean radiation dosage, time of onset after radiation therapy, or initial nutritional assessment data. Differences statistically could be found between groups II and III and I and IV regarding nutritional assessment data, nitrogen balance, radiographic and clinical parameters after therapy, with marked improvement noted in groups II and III. We conclude that a treatment regimen consisting of total parenteral nutrition and bowel rest is beneficial in the treatment of radiation enteritis. Methylprednisolone appears to enhance this effect and indeed, may be responsible for a longer lasting response.

  14. Re-irradiation using 3-dimensional conformal radiation therapy for definitive treatment of 140 cases of locally recurrent nasopharyngeal carcinoma%140例局部复发鼻咽癌患者三维适形放疗的疗效分析

    Institute of Scientific and Technical Information of China (English)

    邱素芳; 林少俊; 陆军; 周衍; 潘建基

    2011-01-01

    Background and purpose: Local recurrences of nasopharyngeal carcinoma (NPC) may be salvaged by re-irradiation using conventional techniques, but with significant morbidity. Three-dimensional conformal radiation therapy (3D-CRT) may improve the therapeutic ratio by reducing doses to normal tissue. The aim of this study was to address the efficacy and toxicity profile of 3D-CRT for 140 patients with locally recurrent NPC. Methods: From May 1997 to Jun. 2009,140 patients diagnosed with locally recurrent NPC by biopsy and/or CT/MRI evidence of progressive skull base erosion and clinical symptoms were treated with 3D-CRT. Median time to recurrence was 27.5 months (ranged from 1 to 156 months) after the completion of conventional radiation to definitive dose. 50.7% of the cases had rTM classification. Minimum planned doses of 3D-CRT treatment were 59.4-60 Gy in 1.8-2 Gy per daily fraction to the gross disease with margins, with or without chemotherapy. Results: The median dose to the recurrent tumor of reirradiation was 62 Gy (ranged from 50 to 77.4 Gy). With a median follow-up of 25.5 months (ranged from 3 to 135 months), the overall survival (OS), disease-free survival (DFS), locoregional recurrence-free survival (LRRFS) rates at 3- and 5-year were 44.53% vs 31%, 42.82 vs 29.13%, 44.19% vs 30.76%, respectively. Moderate to severe late toxicities were noted in 48 patients (34.3%). Thirteen patients (9.29%) had posterior nasal space ulceration, 21 (15%) developed to cranial nerve palsies, 20 (14.3%) had trismus, and 16(11.4%) suffered deafness. Older age was an adverse prognostic factor. Conclusion: Re-irradiation with 3D-CRT provides reasonable long-term control in patients with locally recurrent NPC with acceptable profile of adverse-effects. The overall survival at 3- and 5-year were 44.53% vs 31%.%背景与目的:局部复发鼻咽癌再次放疗的方式很多,但常规放疗后良反应大,目前关于三维适形放疗(three dimensional conformal radiation therapy

  15. Surgical treatment of intestinal radiation injury

    Energy Technology Data Exchange (ETDEWEB)

    Maekelae, J.Ne.; Nevasaari, K.; Kairaluoma, M.I.

    1987-10-01

    A review of 43 consecutive patients requiring operation for serious intestinal radiation injury was undertaken to elucidate the efficacy of surgical treatment. The most common site of radiation injury was the rectum (19 cases), followed by the small bowel (13 cases), the colon (7 cases), and the combination of these (4 cases). The overall operative mortality was 14%; morbidity, 47%; and the postoperative symptom-free period, 18 +/- 30 months. Colostomy (N = 20) carried the lowest risk of mortality, 0%, as compared with resection (N = 17) and bypass procedure (N = 6), which were accompanied by the mortalities of 24% and 33%, respectively. During the follow-up (3-13 years) 12 patients (28%) died of recurrent cancer and 9 patients (21%) of persistent radiation injury, which yielded an overall mortality of 65% after resection and 50% and 65% after bypass and colostomy procedures, respectively. Continuing radiation damage led to 15 late reoperations. Ten of these were performed after colostomy, four after resection, and one after bypass. We conclude that colostomy cannot be regarded as a preferred operative method, because it does not prevent the progression of radiation injury and because it is, for this reason, associated with a higher late-complication rate. A more radical surgery is recommended but with the limitation that the operative method must be adapted to the operative finding.

  16. Dose computation in conformal radiation therapy including geometric uncertainties: Methods and clinical implications

    Science.gov (United States)

    Rosu, Mihaela

    The aim of any radiotherapy is to tailor the tumoricidal radiation dose to the target volume and to deliver as little radiation dose as possible to all other normal tissues. However, the motion and deformation induced in human tissue by ventilatory motion is a major issue, as standard practice usually uses only one computed tomography (CT) scan (and hence one instance of the patient's anatomy) for treatment planning. The interfraction movement that occurs due to physiological processes over time scales shorter than the delivery of one treatment fraction leads to differences between the planned and delivered dose distributions. Due to the influence of these differences on tumors and normal tissues, the tumor control probabilities and normal tissue complication probabilities are likely to be impacted upon in the face of organ motion. In this thesis we apply several methods to compute dose distributions that include the effects of the treatment geometric uncertainties by using the time-varying anatomical information as an alternative to the conventional Planning Target Volume (PTV) approach. The proposed methods depend on the model used to describe the patient's anatomy. The dose and fluence convolution approaches for rigid organ motion are discussed first, with application to liver tumors and the rigid component of the lung tumor movements. For non-rigid behavior a dose reconstruction method that allows the accumulation of the dose to the deforming anatomy is introduced, and applied for lung tumor treatments. Furthermore, we apply the cumulative dose approach to investigate how much information regarding the deforming patient anatomy is needed at the time of treatment planning for tumors located in thorax. The results are evaluated from a clinical perspective. All dose calculations are performed using a Monte Carlo based algorithm to ensure more realistic and more accurate handling of tissue heterogeneities---of particular importance in lung cancer treatment planning.

  17. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a (60)Co Magnetic Resonance Image Guidance Radiation Therapy System

    DEFF Research Database (Denmark)

    Wooten, H Omar; Green, Olga; Yang, Min

    2015-01-01

    % prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range doses >20 Gy. The mean doses for all (60)Co plan OARs were within......PURPOSE: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating (60)Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. METHODS AND MATERIALS...... plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The (60)Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses...

  18. Adaptive functioning of childhood brain tumor survivors following conformal radiation therapy.

    Science.gov (United States)

    Ashford, Jason M; Netson, Kelli L; Clark, Kellie N; Merchant, Thomas E; Santana, Victor M; Wu, Shengjie; Conklin, Heather M

    2014-05-01

    Adaptive functioning is not often examined in childhood brain tumor (BT) survivors, with the few existing investigations relying on examiner interviews. Parent questionnaires may provide similar information with decreased burden. The purpose of this study was: (1) to examine adaptive behaviors in BT survivors relative to healthy peer and cancer survivor groups, and (2) to explore the validity of a parent questionnaire in relation to an examiner administered interview. Participants (age 13.11 ± 2.98 years) were BT survivors treated with conformal radiation therapy (n = 50), healthy siblings of BT survivors (n = 39) and solid tumor (ST) survivors who did not receive CNS-directed therapy (n = 40). Parents completed the Adaptive Behavior Assessment System–2nd Edition (ABAS-II). For a subset of the BT cohort (n = 32), examiners interviewed the parents using the Vineland Adaptive Behavior Scales (VABS) within 12 months. Groups differed significantly on each of the ABAS-II indices and the general adaptive composite, with the BT group scoring lower than the sibling and ST groups across indices. Executive functioning, but not IQ, was associated with adaptive skills; no clear pattern of clinical and demographic predictors was established. VABS scores were correlated with ABAS-II scores on nearly all indices. BT survivors showed significantly lower adaptive functioning when compared to healthy and cancer controls. The ABAS-II proved sensitive to these behavioral limitations and was consistent with scores on the VABS. The use of a parent questionnaire to assess adaptive functioning enhances survivorship investigations by increasing flexibility of assessment and decreasing examiner burden.

  19. The clinical potential of high energy, intensity and energy modulated electron beams optimized by simulated annealing for conformal radiation therapy

    Science.gov (United States)

    Salter, Bill Jean, Jr.

    Purpose. The advent of new, so called IVth Generation, external beam radiation therapy treatment machines (e.g. Scanditronix' MM50 Racetrack Microtron) has raised the question of how the capabilities of these new machines might be exploited to produce extremely conformal dose distributions. Such machines possess the ability to produce electron energies as high as 50 MeV and, due to their scanned beam delivery of electron treatments, to modulate intensity and even energy, within a broad field. Materials and methods. Two patients with 'challenging' tumor geometries were selected from the patient archives of the Cancer Therapy and Research Center (CTRC), in San Antonio Texas. The treatment scheme that was tested allowed for twelve, energy and intensity modulated beams, equi-spaced about the patient-only intensity was modulated for the photon treatment. The elementary beams, incident from any of the twelve allowed directions, were assumed parallel, and the elementary electron beams were modeled by elementary beam data. The optimal arrangement of elementary beam energies and/or intensities was optimized by Szu-Hartley Fast Simulated Annealing Optimization. Optimized treatment plans were determined for each patient using both the high energy, intensity and energy modulated electron (HIEME) modality, and the 6 MV photon modality. The 'quality' of rival plans were scored using three different, popular objective functions which included Root Mean Square (RMS), Maximize Dose Subject to Dose and Volume Limitations (MDVL - Morrill et. al.), and Probability of Uncomplicated Tumor Control (PUTC) methods. The scores of the two optimized treatments (i.e. HIEME and intensity modulated photons) were compared to the score of the conventional plan with which the patient was actually treated. Results. The first patient evaluated presented a deeply located target volume, partially surrounding the spinal cord. A healthy right kidney was immediately adjacent to the tumor volume, separated

  20. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a {sup 60}Co Magnetic Resonance Image Guidance Radiation Therapy System

    Energy Technology Data Exchange (ETDEWEB)

    Wooten, H. Omar, E-mail: hwooten@radonc.wustl.edu; Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H. Harold; Mutic, Sasa

    2015-07-15

    Purpose: This work describes a commercial treatment planning system, its technical features, and its capabilities for creating {sup 60}Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. Methods and Materials: The ViewRay treatment planning system (Oakwood Village, OH) was used to create {sup 60}Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The {sup 60}Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. Results: All {sup 60}Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for {sup 60}Co was within <1% and 3% of linac plans for 100% and 95% prescription reference isodoses, respectively, and heterogeneity was on average 4% greater. Comparisons of OAR mean dose showed generally better sparing with linac plans in the low-dose range <20 Gy, but comparable sparing for organs with mean doses >20 Gy. The mean doses for all {sup 60}Co plan OARs were within clinical tolerances. Conclusions: A commercial {sup 60}Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system.

  1. 三维适形放疗计划系统中照射射束自动建模方法的研究和实现%Research and application of beam auto-modeling method for three-dimensional conformal radiation therapy treatment planning system

    Institute of Scientific and Technical Information of China (English)

    李佳; 祝庆军; 刘松林; 陈志

    2015-01-01

    三维适形放疗计划系统需要根据射束的不同类型和方向,在照射位置和区域上覆盖目标(肿瘤)区域的同时避免周围正常组织的过量照射,确保照射精度。发展了一种射束建模方法:①通过推导坐标系转换矩阵,将病人影像坐标系统下的三维病人模型转换到射束坐标系下;②计算照射目标中心点坐标并以此确定照射距离和射束源位置;③根据照射目标在等中心平面上的投影确定照射区域大小。应用该方法,实现了具有三维可视效果和友好交互性的射束模块。采用美国医学物理协会55号报告(AAPM 55)中基准测例和临床病人影像数据,与某商业适形放疗计划系统的射束模块进行测试比较,验证了本方法的有效性和正确性。%To insure the accuracy of irradiation ,the three‐dimensional conformal radiation therapy (3DCRT ) treatment planning system (T PS ) should ,based on the types and orientations of the beam ,automatically calculate the source position and the field size of the irradiation beam to cover the target (tumor) volume w hile avoiding excessive irradiation of the surrounding tissues . A beam modeling method was developed :first ,based on the derived matrix of coordinate system transformation ,the 3D patient model is tranfered from the patient coordinate system to the beam coordinate system ;then , the iso‐center coordinate of the target is caculated , from w hich the coordinate of the beam source is derived ;finally , the target volume is projected onto the iso‐center plane to identify the field size of the irradiation beam .By implementing of this method ,the beam modeling module was developed with features of 3D visualization and a friendly user interface .The accuracy and efficiency of this module was verified based on the benchmark cases of the AAPM report 55 and the clinical patient image data by testing and comparing it with the beam modeling module of

  2. Rectal planning risk volume correlation with acute and late toxicity in 3-dimensional conformal radiation therapy for prostate cancer.

    Science.gov (United States)

    Dias, R S; Giordani, A J; Souhami, L; Segreto, R A; Segreto, H R C

    2011-12-01

    The purpose of this study was to evaluate rectum motion during 3-Dimensional conformal radiation therapy (3D-CRT) in prostate cancer patients, to derive a planning volume at risk (PRV) and to correlate the PRV dose-volume histograms (DVH) with treatment complications.This study was conducted in two phases. Initially, the PRV was defined prospectively in 50 consecutive prostate cancer patients (Group 1) who received a radical course of 3-D CRT. Then, the obtained PRV was used in the radiotherapy planning of these same 50 patients plus another 59 prostate cancer patients (Group 2) previously treated between 2004 and 2008. All these patients' data, including the rectum and PRV DVHs, were correlated to acute and late complications, according to the Common Toxicity Criteria (CTC) v4.0.The largest displacement occurred in the anterior axis. Long-term gastrointestinal (GI) complications grade ≥ 2 were seen in 9.2% of the cases. Factors that influenced acute GI reactions were: doses at 25% (p 5 0.011) and 40% (p 5 0.005) of the rectum volume and at 40% of the PRV (p 5 0.012). The dose at 25% of the rectum volume (p 5 0.033) and acute complications ≥ grade 2 (p 5 0.018) were prognostic factors for long-term complications. The PRV DVH did not correlate with late toxicity. The rectum showed a significant inter-fraction motion during 3D-CRT for prostate cancer. PRV dose correlated with acute gastrointestinal complications and may be a useful tool to predict and reduce their occurrence.

  3. Radiobiological evaluation of prostate cancer IMRT and conformal-RT plans using different treatment protocols.

    Science.gov (United States)

    Mavroidis, Panayiotis; Komisopoulos, Georgios; Buckey, Courtney; Mavroeidi, Margarita; Swanson, Gregory P; Baltas, Dimos; Papanikolaou, Nikos; Stathakis, Sotirios

    2017-08-01

    The purpose of this study is to evaluate the clinical efficacy of both step-and-shoot IMRT and 3D-Conformal Radiation Therapy modalities (CRT) in treating prostate cancer using radiobiological measures. Another aim was to estimate the risks for developing secondary malignancies in bladder and rectum due to radiotherapy from the corresponding modalities. The treatment plans of ten prostate cancer patients were developed using IMRT and CRT. For the IMRT plans, two beam energies and two treatment protocols were used (the RTOG 0415 and a most restrictive one proposed by Fox Chase Cancer Center (FCCC)). For the evaluation of these plans, the complication-free tumor control probability, the total probability of injury, the total probability of control/benefit, and the biologically effective uniform dose were employed. Furthermore, based on the dosimetric data of IMRT and CRT, the risk for secondary malignancies was calculated for bladder and rectum. The average risk for secondary malignancy was lower for the bladder (0.37%) compared to the rectum (0.81%) based on all the treatment plans of the ten prostate cancer patients. The highest average risk for secondary malignancy for bladder and rectum was for the CRT-6X modality (0.46% and 1.12%, respectively) and the lowest was for the IMRT RTOG-18X modality (0.33% and 0.56%, respectively). The ≥ Grade 2 LENT/SOMA response probability was lower for the bladder than for the rectum in all the plans. For the bladder the highest average value was for the IMRT RTOG-18X (0.9%) and the lowest was for the CRT-18X modality (0.1%). For the rectum, the highest average value was for the IMRT RTOG-6X (11.9%) and the lowest was for the IMRT FCCC-18X modality (2.2%). By using radiobiological measures it is shown that the IMRT FCCC plans had the lowest risks for normal tissue complications, whereas the IMRT RTOG had the highest. Regarding the risk for secondary malignancies, the CRT plans showed the highest values for both bladder and

  4. Operative treatment of radiation-induced fistulae

    Energy Technology Data Exchange (ETDEWEB)

    Balslev, I.; Harling, H.

    1987-01-01

    Out of 136 patients with radiation-induced intestinal complications, 45 had fistulae. Twenty-eight patients had rectovaginal fistulae while the remainder had a total of 13 different types of fistulae. Thirty-seven patients were treated operatively and eight were treated conservatively. Thirty-three patients were submitted to operation for rectal fistulae. Of these, 28 were treated by defunctioning colostomy, three were treated by Hartmann's method and resection and primary anastomosis was carried out in two patients. In the course of the period of observation, 35% of the patients developed new radiation damage. The frequency in the basic material without fistulae was 21% (0.05treatment of rectal fistula is a reasonable form of treatment in elderly patients and in case of recurrence. Younger patients should be assessed in a special department in view of the possibility of a sphincter-preserving procedure following resection of the rectum and restorative anastomosis. 11 refs.

  5. Optimizing Collimator Margins for Isotoxically Dose-Escalated Conformal Radiation Therapy of Non-Small Cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Warren, Samantha, E-mail: Samantha.warren@oncology.ox.ac.uk [Department of Oncology, Gray Institute of Radiation Oncology and Biology, University of Oxford, Oxford (United Kingdom); Oxford Cancer Centre, Oxford University Hospitals, Oxford (United Kingdom); Panettieri, Vanessa [William Buckland Radiotherapy Centre, Alfred Hospital, Commercial Road, Melbourne (Australia); Panakis, Niki; Bates, Nicholas [Oxford Cancer Centre, Oxford University Hospitals, Oxford (United Kingdom); Lester, Jason F. [Velindre Cancer Centre, Velindre Road, Whitchurch, Cardiff (United Kingdom); Jain, Pooja [Clatterbridge Cancer Centre, Clatterbridge Road, Wirral (United Kingdom); Landau, David B. [Department of Radiotherapy, Guy' s and St. Thomas' NHS Foundation Trust, London (United Kingdom); Nahum, Alan E.; Mayles, W. Philip M. [Clatterbridge Cancer Centre, Clatterbridge Road, Wirral (United Kingdom); Fenwick, John D. [Department of Oncology, Gray Institute of Radiation Oncology and Biology, University of Oxford, Oxford (United Kingdom); Oxford Cancer Centre, Oxford University Hospitals, Oxford (United Kingdom)

    2014-04-01

    Purpose: Isotoxic dose escalation schedules such as IDEAL-CRT [isotoxic dose escalation and acceleration in lung cancer chemoradiation therapy] (ISRCTN12155469) individualize doses prescribed to lung tumors, generating a fixed modeled risk of radiation pneumonitis. Because the beam penumbra is broadened in lung, the choice of collimator margin is an important element of the optimization of isotoxic conformal radiation therapy for lung cancer. Methods and Materials: Twelve patients with stage I-III non-small cell lung cancer (NSCLC) were replanned retrospectively using a range of collimator margins. For each plan, the prescribed dose was calculated according to the IDEAL-CRT isotoxic prescription method, and the absolute dose (D{sub 99}) delivered to 99% of the planning target volume (PTV) was determined. Results: Reducing the multileaf collimator margin from the widely used 7 mm to a value of 2 mm produced gains of 2.1 to 15.6 Gy in absolute PTV D{sub 99}, with a mean gain ± 1 standard error of the mean of 6.2 ± 1.1 Gy (2-sided P<.001). Conclusions: For NSCLC patients treated with conformal radiation therapy and an isotoxic dose prescription, absolute doses in the PTV may be increased by using smaller collimator margins, reductions in relative coverage being offset by increases in prescribed dose.

  6. A precision 3D conformal treatment technique in rats: application to whole brain radiotherapy with hippocampal avoidance.

    Science.gov (United States)

    Yoon, Suk W; Cramer, Christina K; Miles, Devin A; Reinsvold, Michael H; Joo, Kyeung M; Kirsch, David G; Oldham, Mark

    2017-08-24

    To develop and validate 3D conformal hippocampal sparing whole-brain radiation therapy (HA-WBRT) for Wistar rats utilizing precision 3D printed immobilization and micro-blocks. This technique paves the way for future pre-clinical studies investigating brain treatments that reduce neurotoxicity. A novel pre-clinical treatment planning and delivery process was developed to enable precision 3D conformal treatment and hippocampal avoidance capability for the Xrad 225cx small animal irradiator. A range of conformal avoidance plans were evaluated consisting of equi-angularly spaced co-planar axial beams, with plans containing 2, 4, 7, and 8 fields. The hippocampal sparing and coverage of these plans were investigated through Monte Carlo dose calculation (SmART-Plan Xrad 225cx planning system). Treatment delivery was implemented through a novel process where hippocampal block shapes were computer-generated from an MRI rat atlas which was registered to on-board cone-beam-CT of the rat in treatment position. The blocks were 3D-printed with a tungsten-doped filament at lateral resolution of 80μm. Precision immobilization was achieved utilizing a 3D-printed support system which enabled angled positioning of the rat head in supine position and bite-block to improve coverage of the central diencephalon. Treatment delivery was verified on rodent-morphic Presage(®) 3D dosimeters optically scanned at 0.2mm isotropic resolution. Biological verification of hippocampal avoidance was performed with immunohistologic staining. All simulated plans spared the hippocampus while delivering high dose to the brain (22.5-26.2Gy mean dose to brain at mean hippocampal dose of 7Gy). No significant improvement in hippocampal sparing was observed by adding beams beyond 4 fields. Dosimetric sparing of hippocampal region of the 4-field plan was verified with the Presage(®) dosimeter (mean dose = 9.6Gy, D100% = 7.1Gy). Simulation and dosimeter match at distance-to-agreement of 2mm and dose

  7. Motion-Compensated Estimation of Delivered Dose during External BeamRadiation Therapy: Implementation in Philips’ Pinnacle3 Treatment Planning System

    NARCIS (Netherlands)

    Bharat, S.; Parikh, P.; Noel, C.; Meltsner, M.; Bzdusek, K.; Kaus, M.

    2012-01-01

    Purpose: Recent research efforts investigating dose escalation techniques for three-dimensional conformal radiation therapy (3D CRT) andintensity modulated radiation therapy (IMRT) have demonstrated great benefit when high-dose hypofractionated treatment schemes are implemented16,21. The use of the

  8. Conformal Infinity

    Directory of Open Access Journals (Sweden)

    Frauendiener Jörg

    2000-08-01

    Full Text Available The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, ``conformal infinity'' is related with almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved out of physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation and how it lends itself very naturally to solve radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  9. Conformal Infinity

    Science.gov (United States)

    Frauendiener, Jörg

    2004-12-01

    The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, "conformal infinity" is related to almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved from physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation, and how it lends itself very naturally to the solution of radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  10. Conformal Infinity

    Directory of Open Access Journals (Sweden)

    Frauendiener Jörg

    2004-01-01

    Full Text Available The notion of conformal infinity has a long history within the research in Einstein's theory of gravity. Today, 'conformal infinity' is related to almost all other branches of research in general relativity, from quantisation procedures to abstract mathematical issues to numerical applications. This review article attempts to show how this concept gradually and inevitably evolved from physical issues, namely the need to understand gravitational radiation and isolated systems within the theory of gravitation, and how it lends itself very naturally to the solution of radiation problems in numerical relativity. The fundamental concept of null-infinity is introduced. Friedrich's regular conformal field equations are presented and various initial value problems for them are discussed. Finally, it is shown that the conformal field equations provide a very powerful method within numerical relativity to study global problems such as gravitational wave propagation and detection.

  11. Aggregation and conformational change of mushroom (Agaricus bisporus) polyphenoloxidase subjected to thermal treatment.

    Science.gov (United States)

    Zhou, Lei; Liu, Wei; Zou, Liqiang; Xiong, Zhiqiang; Hu, Xiuting; Chen, Jun

    2017-01-01

    This study investigated changes in the activity, conformation and microstructure of mushroom polyphenoloxidase (PPO) subjected to thermal treatment. The inactivation of PPO can be achieved by high temperature-short time or mild temperature-long time treatment. Circular dichroism and fluorescence spectra suggested that heating process induced the rearrangement of secondary structure and the disruption of tertiary structure. Red shifts of fluorescence spectra showed positive correlations with the inactivation rate of PPO. There were significant differences in the conformation and molecular microstructure among PPO samples with the same relative activity, which were obtained by treating PPO at 45, 55 and 65°C for different times. In summary, PPO molecules were deformed at mild temperature, while higher temperature induced the formation of large aggregates. PPO with the same relative activity might exist in different forms.

  12. Single-arm phase II study of conformal radiation therapy and temozolomide plus fractionated stereotactic conformal boost in high-grade gliomas. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Balducci, Mario; Manfrida, Stefania; Mangiola, Annunziato; Fiorentino, Alba; D' Agostino, Giuseppe Roberto; Frascino, Vincenzo; Dinapoli, Nicola; Mantini, Giovanna; Albanese, Alessio; De Bonis, Pasquale; Chiesa, Silvia; Valentini, Vincenzo; Anile, Carmelo; Cellini, Numa [Dept. of Radiotherapy, Catholic Univ. of the Sacred Heart, Rome (Italy); Apicella, Giuseppina [Dept. of Radiotherapy, Catholic Univ. of the Sacred Heart, Rome (Italy); Dept. of Radiotherapy, Univ. Hospital Maggiore della Carita, Novara (Italy); Azario, Luigi [Dept. of Physics, Catholic Univ. of the Sacred Heart, Rome (Italy)

    2010-10-15

    Purpose: To assess survival, local control and toxicity using fractionated stereotactic conformal radiotherapy (FSCRT) boost and temozolomide in high-grade gliomas (HGGs). Patients and Methods: Patients affected by HGG, with a CTV{sub 1} (clinical target volume, representing tumor bed {+-} residual tumor + a margin of 5 mm) {<=} 8 cm were enrolled into this phase II study. Radiotherapy (RT, total dose 6,940 cGy) was administered using a combination of two different techniques: three-dimensional conformal radiotherapy (3D-CRT, to achieve a dose of 5,040 or 5,940 cGy) and FSCRT boost (19 or 10 Gy) tailored by CTV{sub 1} diameter ({<=} 6 cm and > 6 cm, respectively). Temozolomide (75 mg/m{sup 2}) was administered during the first 2 or 4 weeks of RT, After the end of RT, temozolomide (150-200 mg/m{sup 2}) was administered for at least six cycles. The sample size of 41 patients was assessed by the single proportion-powered analysis. Results: 41 patients (36 with glioblastoma multiforme [GBM] and five with anaplastic astrocytoma [AA]) were enrolled; RTOG neurological toxicities G1-2 and G3 were 12% and 3%, respectively. Two cases of radionecrosis were observed. At a median follow-up of 44 months (range 6-56 months), global and GBM median overall survival (05) were 30 and 28 months. The 2-year survival rate was significantly better compared to the standard treatment (63% vs. 26.5%; p < 0.00001). Median progression-free survival (PFS) was 11 months, in GBM patients 10 months. Conclusion: FSCRT boost plus temozolomide is well tolerated and seems to increase survival compared to the standard treatment in patients with HGG. (orig.)

  13. Quality of Intensity Modulated Radiation Therapy Treatment Plans Using a ⁶⁰Co Magnetic Resonance Image Guidance Radiation Therapy System.

    Science.gov (United States)

    Wooten, H Omar; Green, Olga; Yang, Min; DeWees, Todd; Kashani, Rojano; Olsen, Jeff; Michalski, Jeff; Yang, Deshan; Tanderup, Kari; Hu, Yanle; Li, H Harold; Mutic, Sasa

    2015-07-15

    This work describes a commercial treatment planning system, its technical features, and its capabilities for creating (60)Co intensity modulated radiation therapy (IMRT) treatment plans for a magnetic resonance image guidance radiation therapy (MR-IGRT) system. The ViewRay treatment planning system (Oakwood Village, OH) was used to create (60)Co IMRT treatment plans for 33 cancer patients with disease in the abdominal, pelvic, thorax, and head and neck regions using physician-specified patient-specific target coverage and organ at risk (OAR) objectives. Backup plans using a third-party linear accelerator (linac)-based planning system were also created. Plans were evaluated by attending physicians and approved for treatment. The (60)Co and linac plans were compared by evaluating conformity numbers (CN) with 100% and 95% of prescription reference doses and heterogeneity indices (HI) for planning target volumes (PTVs) and maximum, mean, and dose-volume histogram (DVH) values for OARs. All (60)Co IMRT plans achieved PTV coverage and OAR sparing that were similar to linac plans. PTV conformity for (60)Co was within 20 Gy. The mean doses for all (60)Co plan OARs were within clinical tolerances. A commercial (60)Co MR-IGRT device can produce highly conformal IMRT treatment plans similar in quality to linac IMRT for a variety of disease sites. Additional work is in progress to evaluate the clinical benefit of other novel features of this MR-IGRT system. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Radiation treatment for newly diagnosed esophageal cancer with prior radiation to the thoracic cavity

    Energy Technology Data Exchange (ETDEWEB)

    Sponseller, Patricia, E-mail: sponselp@uw.edu [University of Wisconsin at La Crosse, La Crosse, WI (United States); Lenards, Nishele [Department of Radiation Oncology, University of Washington, Seattle, WA (United States); Kusano, Aaron; Patel, Shilpen [University of Wisconsin at La Crosse, La Crosse, WI (United States)

    2014-10-01

    The purpose of this report is to communicate the use of single-positron emission computed tomography scan in planning radiation treatments for patients with a history of radiation to the thoracic cavity. A patient presented with obstructive esophageal cancer, having previously received chemotherapy and radiation therapy to the mediastinum for non-Hodgkin lymphoma 11 years earlier. Owing to a number of comorbidities, the patient was not a surgical candidate and was referred to the University of Washington Medical Center for radiation therapy. Prior dose to the spinal cord and lung were taken into account before designing the radiation treatment plan.

  15. The treatment planning of segmental, conformal stereotactic radiosurgery utilizing a standard multileaf collimator.

    Science.gov (United States)

    Archer, P G; Balter, J M; Ross, D A; Hayman, J A; Sandler, H M

    1999-01-01

    Over a period of approximately 3 years, our institution has implemented and refined a system of Stereotactic Radiosurgery (SRS) which utilizes the standard multi leaf collimator (MLC) of the Scanditronix MM50 Racetrack Microtron and treats in an arrangement of segmental "pseudo-arcs." This system employs a commercial BRW based stereotactic frame which is mounted to the treatment table. With the exception of the table-mounted frame hardware there have been no modifications to the treatment machine to accommodate these treatments. By use of standard evaluation parameters (e.g., treatment time, planning time, dose conformance and dose heterogeneity ratios) this system compares quite favorably with reported data from institutions treating SRS with either a GammaKnife or a standard linear accelerator with tertiary collimators.

  16. NIR Laser Radiation Induced Conformational Changes and Tunneling Lifetimes of High-Energy Conformers of Amino Acids in Low-Temperature Matrices

    Science.gov (United States)

    Bazso, Gabor; Najbauer, Eszter E.; Magyarfalvi, Gabor; Tarczay, Gyorgy

    2013-06-01

    We review our recent results on combined matrix isolation FT-IR and NIR laser irradiation studies on glycine alanine, and cysteine. The OH and the NH stretching overtones of the low-energy conformers of these amino acids deposited in Ar, Kr, Xe, and N_{2} matrices were irradiated. At the expense of the irradiated conformer, other conformers were enriched and new, high-energy, formerly unobserved conformers were formed in the matrices. This enabled the separation and unambiguous assignment of the vibrational transitions of the different conformers. The main conversion paths and their efficiencies are described qualitatively showing that there are significant differences in different matrices. It was shown that the high-energy conformer decays in the matrix by H-atom tunneling. The lifetimes of the high-energy conformers in different matrices were measured. Based on our results we conclude that some theoretically predicted low-energy conformers of amino acids are likely even absent in low-energy matrices due to fast H-atom tunneling. G. Bazso, G. Magyarfalvi, G. Tarczay J. Mol. Struct. 1025 (Light-Induced Processes in Cryogenic Matrices Special Issue) 33-42 (2012). G. Bazso, G. Magyarfalvi, G. Tarczay J. Phys. Chem. A 116 (43) 10539-10547 (2012). G. Bazso, E. E. Najbauer, G. Magyarfalvi, G. Tarczay J. Phys. Chem. A in press, DOI: 10.1021/jp400196b. E. E. Najbauer, G. Bazso, G. Magyarfalvi, G. Tarczay in preparation.

  17. The Rapid Response Radiation Survey (R3S) Mission Using the HISat Conformal Satellite Architecture

    Science.gov (United States)

    Miller, Nathanael

    2015-01-01

    The Rapid Response Radiation Survey (R3S) experiment, designed as a quick turnaround mission to make radiation measurements in LEO, will fly as a hosted payload in partnership with NovaWurks using their Hyper-integrated Satlet (HiSat) architecture. The need for the mission arises as the Nowcast of Atmospheric Ionization Radiation for Aviation Safety (NAIRAS) model moves from a research effort into an operational radiation assessment tool. The data collected by R3S, in addition to the complementary data from a NASA Langley Research Center (LaRC) atmospheric balloon mission entitled Radiation Dosimetry Experiment (RaDX), will validate exposure prediction capabilities of NAIRAS. This paper discusses the development of the R3S experiment as made possible by use of the HiSat architecture. The system design and operational modes of the experiment are described, as well as the experiment interfaces to the HiSat satellite via the user defined adapter (UDA) provided by NovaWurks. This paper outlines the steps taken by the project to execute the R3S mission in the 4 months of design, build, and test. Finally, description of the engineering process is provided, including the use of facilitated rapid/concurrent engineering sessions, the associated documentation, and the review process employed.

  18. Preliminary Toxicity Analysis of 3-Dimensional Conformal Radiation Therapy Versus Intensity Modulated Radiation Therapy on the High-Dose Arm of the Radiation Therapy Oncology Group 0126 Prostate Cancer Trial

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, Jeff M., E-mail: jmichalski@radonc.wustl.edu [Department of Radiation Oncology Washington University Medical Center, St. Louis, Missouri (United States); Yan, Yan [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Watkins-Bruner, Deborah [Emory University School of Nursing, Atlanta, Georgia (United States); Bosch, Walter R. [Department of Radiation Oncology Washington University Medical Center, St. Louis, Missouri (United States); Winter, Kathryn [Radiation Therapy Oncology Group Statistical Center, Philadelphia, Pennsylvania (United States); Galvin, James M. [Department of Radiation Oncology Thomas Jefferson University Hospital, Philadelphia, Pennsylvania (United States); Bahary, Jean-Paul [Department of Radiation Oncology Centre Hospitalier de l' Université de Montréal-Notre Dame, Montreal, QC (Canada); Morton, Gerard C. [Department of Radiation Oncology Toronto-Sunnybrook Regional Cancer Centre, Toronto, ON (Canada); Parliament, Matthew B. [Department of Oncology Cross Cancer Institute, Edmonton, AB (Canada); Sandler, Howard M. [Department of Radiation Oncology Samuel Oschin Comprehensive Cancer Institute, Cedars-Sinai Medical Center, Los Angeles, California (United States)

    2013-12-01

    Purpose: To give a preliminary report of clinical and treatment factors associated with toxicity in men receiving high-dose radiation therapy (RT) on a phase 3 dose-escalation trial. Methods and Materials: The trial was initiated with 3-dimensional conformal RT (3D-CRT) and amended after 1 year to allow intensity modulated RT (IMRT). Patients treated with 3D-CRT received 55.8 Gy to a planning target volume that included the prostate and seminal vesicles, then 23.4 Gy to prostate only. The IMRT patients were treated to the prostate and proximal seminal vesicles to 79.2 Gy. Common Toxicity Criteria, version 2.0, and Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer late morbidity scores were used for acute and late effects. Results: Of 763 patients randomized to the 79.2-Gy arm of Radiation Therapy Oncology Group 0126 protocol, 748 were eligible and evaluable: 491 and 257 were treated with 3D-CRT and IMRT, respectively. For both bladder and rectum, the volumes receiving 65, 70, and 75 Gy were significantly lower with IMRT (all P<.0001). For grade (G) 2+ acute gastrointestinal/genitourinary (GI/GU) toxicity, both univariate and multivariate analyses showed a statistically significant decrease in G2+ acute collective GI/GU toxicity for IMRT. There were no significant differences with 3D-CRT or IMRT for acute or late G2+ or 3+ GU toxicities. Univariate analysis showed a statistically significant decrease in late G2+ GI toxicity for IMRT (P=.039). On multivariate analysis, IMRT showed a 26% reduction in G2+ late GI toxicity (P=.099). Acute G2+ toxicity was associated with late G3+ toxicity (P=.005). With dose–volume histogram data in the multivariate analysis, RT modality was not significant, whereas white race (P=.001) and rectal V70 ≥15% were associated with G2+ rectal toxicity (P=.034). Conclusions: Intensity modulated RT is associated with a significant reduction in acute G2+ GI/GU toxicity. There is a trend for a

  19. The Rapid Response Radiation Survey (R3S) Mission Using the HiSat Conformal Satellite Architecture

    Science.gov (United States)

    Miller, Nathanael A.; Norman, Ryan B.; Soto, Hector L.; Stewart, Victor A.; Jones, Mark L.; Kowalski, Matthew C.; Ben Shabat, Adam; Gough, Kerry M.; Stavely, Rebecca L.; Shim, Alex C.; hide

    2015-01-01

    The Rapid Response Radiation Survey (R3S) experiment, designed as a quick turnaround mission to make radiation measurements in Low Earth Orbit (LEO), will fly as a hosted payload in partnership with NovaWurks using their Hyper-integrated Satlet (HISat) architecture. The need for the mission arises as the Nowcast of Atmospheric Ionization Radiation for Aviation Safety (NAIRAS) model moves from a research effort into an operational radiation assessment tool. Currently, airline professionals are the second largest demographic of radiation workers and to date their radiation exposure is undocumented in the USA. The NAIRAS model seeks to fill this information gap. The data collected by R3S, in addition to the complementary data from a NASA Langley Research Center (LaRC) atmospheric balloon mission entitled Radiation Dosimetry Experiment (RaD-X), will validate exposure prediction capabilities of NAIRAS. The R3S mission collects total dose and radiation spectrum measurements using a Teledyne µDosimeter and a Liulin-6SA2 LED spectrometer. These two radiation sensors provide a cross correlated radiometric measurement in combination with the Honeywell HMR2300 Smart Digital Magnetometer. The magnetometer assesses the Earth's magnetic field in the LEO environment and allows radiation dose to be mapped as a function of the Earth's magnetic shielding. R3S is also unique in that the radiation sensors will be exposed on the outer surface of the spacecraft, possibly making this the first measurements of the LEO radiation environment with bare sensors. Viability of R3S as an extremely fast turnaround mission is due, in part, to the nature of the robust, well-defined interfaces of the conformal satellite HiSat Architecture. The HiSat architecture, which was developed with the support of the Defense Advanced Research Projects Agency's (DARPA's) Phoenix Program, enabled the R3S system to advance from the first concept to delivery of preliminary design review (PDR) level documents in

  20. Feasibility of using the micro CT imaging system as the conformal radiation therapy facility for small animals

    Science.gov (United States)

    Tu, Shu-Ju; Hsieh, Hui-Ling; Chao, Tsi-Chian; Lee, Chung-Chi

    2009-02-01

    In recent years, there has been an increasing number of integration for using the micro CT scanners, either home-built bench-top or commercially made, as the small animal radiation therapy irradiator in several research groups. In this paper, we study the x-ray beam physics such as the percentage depth dose distribution and their dose conformity characteristics using Monte Carlo simulation method for a series of photon energy levels often found in the current commercial micro CT imaging systems. Micro CT scanners have been one of the key imaging modalities in the current state-of-the-art molecular imaging techniques and their applications in various biomedical research areas have been increasing tremendously in recent years due to the ultra-high image quality. Tumor growth development and the corresponding therapeutic response in the small animal model study can be evaluated by a micro CT imaging system. In the most current advanced commercially available micro CT units, the nominal spatial resolution is typically at the scale of 10.0 μm or less. In current research trend, there have been an increasing number of investigations for the applications of x-ray units to organ-specific and whole-body radiation in dedicated small animal model study. In particular, scientists have identified that the integrated micro CT imagers can be commissioned as the dual-purpose unit for the high spatial resolution image acquisition and radiation delivery. As we all realized that small animal models are important and critical in several studies of experimental (or pre-clinical) radiation therapy research. In this paper, a Monte Carlo code (Penelope) was used to calculate the percentage depth dose distributions at different photon energy levels. Also the corresponding iso-dose contour curves were computed and plotted from the circular CT scanning geometry to study the desired dose conformity property. We note that the selected photon energy range that is included in this work is often

  1. Effect of Gamma Radiation on Sodium Channels in Different Conformations in Neuroblastoma Cells

    Science.gov (United States)

    1986-01-01

    rads). selectively sulphonic acid : Tris. 2-amino-2-hydroxymethylprepane-l.3- reduce sodium currents in isolated frog sciatic dial. nerves under...similar ful in demonstrating structural and functional spectrum of radiosensitivity. A large body of bio- properties of biological membrane macromole...channel function 12-41. One might expect that quences than does disruption of nucleic acids , ionizing radiation, comprising a higher energy spectrum than

  2. Radiation oncology--linking technology and biology in the treatment of cancer.

    Science.gov (United States)

    Coleman, C Norman

    2002-01-01

    Technical advances in radiation oncology including CT-simulation, 3D- conformal and intensity-modulated radiation therapy (IMRT) delivery techniques, and brachytherapy have allowed greater treatment precision and dose escalation. The ability to intensify treatment requires the identification of the critical targets within the treatment field, recognizing the unique biology of tumor, stroma and normal tissue. Precision is technology based while accuracy is biologically based. Therefore, the intensity of IMRT will undoubtedly mean an increase in both irradiation dose and the use of biological agents, the latter considered in the broadest sense. Radiation oncology has the potential and the opportunity to provide major contributions to the linkage between molecular and functional imaging, molecular profiling and novel therapeutics for the emerging molecular targets for cancer treatment. This process of 'credentialing' of molecular targets will require multi disciplinary imaging teams, clinicians and basic scientists. Future advances will depend on the appropriate integration of biology into the training of residents, continuing post graduate education, participation in innovative clinical research and commitment to the support of basic research as an essential component of the practice of radiation oncology.

  3. Treatment of cloud radiative effects in general circulation models

    Energy Technology Data Exchange (ETDEWEB)

    Wang, W.C.; Dudek, M.P.; Liang, X.Z.; Ding, M. [State Univ. of New York, Albany, NY (United States)] [and others

    1996-04-01

    We participate in the Atmospheric Radiation Measurement (ARM) program with two objectives: (1) to improve the general circulation model (GCM) cloud/radiation treatment with a focus on cloud verticle overlapping and layer cloud optical properties, and (2) to study the effects of cloud/radiation-climate interaction on GCM climate simulations. This report summarizes the project progress since the Fourth ARM Science Team meeting February 28-March 4, 1994, in Charleston, South Carolina.

  4. Radiation induced chromatin conformation changes analysed by fluorescent localization microscopy, statistical physics, and graph theory.

    Science.gov (United States)

    Zhang, Yang; Máté, Gabriell; Müller, Patrick; Hillebrandt, Sabina; Krufczik, Matthias; Bach, Margund; Kaufmann, Rainer; Hausmann, Michael; Heermann, Dieter W

    2015-01-01

    It has been well established that the architecture of chromatin in cell nuclei is not random but functionally correlated. Chromatin damage caused by ionizing radiation raises complex repair machineries. This is accompanied by local chromatin rearrangements and structural changes which may for instance improve the accessibility of damaged sites for repair protein complexes. Using stably transfected HeLa cells expressing either green fluorescent protein (GFP) labelled histone H2B or yellow fluorescent protein (YFP) labelled histone H2A, we investigated the positioning of individual histone proteins in cell nuclei by means of high resolution localization microscopy (Spectral Position Determination Microscopy = SPDM). The cells were exposed to ionizing radiation of different doses and aliquots were fixed after different repair times for SPDM imaging. In addition to the repair dependent histone protein pattern, the positioning of antibodies specific for heterochromatin and euchromatin was separately recorded by SPDM. The present paper aims to provide a quantitative description of structural changes of chromatin after irradiation and during repair. It introduces a novel approach to analyse SPDM images by means of statistical physics and graph theory. The method is based on the calculation of the radial distribution functions as well as edge length distributions for graphs defined by a triangulation of the marker positions. The obtained results show that through the cell nucleus the different chromatin re-arrangements as detected by the fluorescent nucleosomal pattern average themselves. In contrast heterochromatic regions alone indicate a relaxation after radiation exposure and re-condensation during repair whereas euchromatin seemed to be unaffected or behave contrarily. SPDM in combination with the analysis techniques applied allows the systematic elucidation of chromatin re-arrangements after irradiation and during repair, if selected sub-regions of nuclei are

  5. An improved treatment of radiation energy flow in the radiation-hydrodynamics code CHARTD

    Energy Technology Data Exchange (ETDEWEB)

    Rottler, J.S.

    1987-05-01

    An improved treatment of radiation transport has been added to the energy flow model in CHARTD. The new energy flow model was derived based on the assumption that the directional dependence of the radiation energy density can be represented by the first two terms of a spherical harmonic expansion, and that the photon energy spectrum can be partitioned into energy groups. This treatment of radiation transport is called the multigroup P-1 approximation, and is an effective description of radiation transport for a broad class of radiation-hydrodynamics problems. A synthetic acceleration scheme is used to solve the differenced multigroup P-1 equations. The coupling between the material field and the radiation field is fully explicit. This report describes the new energy flow model and the acceleration scheme used to solve the difference equations. 15 refs.

  6. Medical treatment of radiation injuries-Current US status

    Energy Technology Data Exchange (ETDEWEB)

    Jarrett, D.G. [OSA - CBD and CDP, 3050 Defense Pentagon, Room 3C257, Washington, DC 20301-3050 (United States)], E-mail: david.jarrett@us.army.mil; Sedlak, R.G.; Dickerson, W.E. [Uniformed Services University, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Avenue, Bethesda, MD 20889-5603 (United States); Reeves, G.I. [Northrop Grumman IT, 8211 Terminal Road, Lorton, VA 22079-1421 (United States)

    2007-07-15

    A nuclear incident or major release of radioactive materials likely would result in vast numbers of patients, many of whom would require novel therapy. Fortunately, the numbers of radiation victims in the United States (USA) have been limited to date. If a mass-casualty situation occurs, there will be a need to perform rapid, accurate dose estimates and to provide appropriate medications and other treatment to ameliorate radiation injury. The medical management of radiation injury is complex. Radiation injury may include acute radiation sickness (ARS) from external and/or internal radiation exposure, internal organ damage from incorporated radioactive isotopes, and cutaneous injury. Human and animal data have shown that optimal medical care may nearly double the survivable dose of ionizing radiation. Current treatment strategies for radiation injuries are discussed with concentration on the medical management of the hematopoietic syndrome. In addition, priority areas for continuing and future research into both acute deterministic injuries and also long-term stochastic sequelae of radiation exposure have been identified. There are several near-term novel therapies that appear to offer excellent prognosis for radiation casualties, and these are also described.

  7. Improved treatment of radiation effects on the skin

    Energy Technology Data Exchange (ETDEWEB)

    Wandl, E.O.; Kaercher, K.H.; Wandl-Hainberger, I.

    1985-04-29

    The treatment concept developed by K.H. Kaercher was extended by a therapy using Elasten S cream. In the course of a highvoltage therapy using fast electrons or cobalt-60, interesting aspects in the treatment and progression of the radiation reactions of the skin were established. The dermato-therapeutic principles layed down by K.H. Kaercher with the treatment palette used hitherto, have without doubt invariably proven their value. The exclusive powder treatment, however, may be made more practical by application of the new treatment cream in accordance with the intervals in radiation treatment or as a basic treatment towards the end of therapy. Furthermore it is ideally suited for the care and after-treatment of skin, strained by radiation. It reduces considerably the remaining visible radiation reactions. The treatment with powder and emulsion has for more than 10 years proven effective. After the excellent results of the new cream during radiation treatment, additional positive effects are expected in a long-term trial which will be reported on separately.

  8. Production of silver nanoparticles in water solution by radiation treatment

    Science.gov (United States)

    Mikhailenko, M. A.; Korobeinikov, M. V.; Bryazgin, A. A.; Tolochko, B. P.

    2017-01-01

    Radiation-chemical synthesis of silver nanoparticles was studied. The silver nanoparticles in arabinogalactan (AG) water solution are stabilized in conglomerates, it is fixed by rise of additional bands in the optical absorption spectra. Pre-radiation treatment of AG causes crosslinking and oxidation. Pretreated AG solution increases the stability of conglomerates containing silver nanoparticles in case of dilution.

  9. Kinetic treatment of radiation reaction effects

    Science.gov (United States)

    Noble, Adam; Gratus, Jonathan; Burton, David; Ersfeld, Bernhard; Islam, M. Ranaul; Kravets, Yevgen; Raj, Gaurav; Jaroszynski, Dino

    2011-05-01

    Modern accelerators and light sources subject bunches of charged particles to quasiperiodic motion in extremely high electric fields, under which they may emit a substantial fraction of their energy. To properly describe the motion of these particle bunches, we require a kinetic theory of radiation reaction. We develop such a theory based on the notorious Lorentz-Dirac equation, and explore how it reduces to the usual Vlasov theory in the appropriate limit. As a simple illustration of the theory, we explore the radiative damping of Langmuir waves.

  10. Analysis of Intensity-Modulated Radiation Therapy (IMRT), Proton and 3D Conformal Radiotherapy (3D-CRT) for Reducing Perioperative Cardiopulmonary Complications in Esophageal Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Ling, Ted C.; Slater, Jerry M.; Nookala, Prashanth; Mifflin, Rachel; Grove, Roger; Ly, Anh M.; Patyal, Baldev; Slater, Jerry D.; Yang, Gary Y., E-mail: gyang@llu.edu [Department of Radiation Medicine, Loma Linda University Medical Center, 11234 Anderson Street, A875, Loma Linda, CA 92354 (United States)

    2014-12-05

    Background. While neoadjuvant concurrent chemoradiotherapy has improved outcomes for esophageal cancer patients, surgical complication rates remain high. The most frequent perioperative complications after trimodality therapy were cardiopulmonary in nature. The radiation modality utilized can be a strong mitigating factor of perioperative complications given the location of the esophagus and its proximity to the heart and lungs. The purpose of this study is to make a dosimetric comparison of Intensity-Modulated Radiation Therapy (IMRT), proton and 3D conformal radiotherapy (3D-CRT) with regard to reducing perioperative cardiopulmonary complications in esophageal cancer patients. Materials. Ten patients with esophageal cancer treated between 2010 and 2013 were evaluated in this study. All patients were simulated with contrast-enhanced CT imaging. Separate treatment plans using proton radiotherapy, IMRT, and 3D-CRT modalities were created for each patient. Dose-volume histograms were calculated and analyzed to compare plans between the three modalities. The organs at risk (OAR) being evaluated in this study are the heart, lungs, and spinal cord. To determine statistical significance, ANOVA and two-tailed paired t-tests were performed for all data parameters. Results. The proton plans showed decreased dose to various volumes of the heart and lungs in comparison to both the IMRT and 3D-CRT plans. There was no difference between the IMRT and 3D-CRT plans in dose delivered to the lung or heart. This finding was seen consistently across the parameters analyzed in this study. Conclusions. In patients receiving radiation therapy for esophageal cancer, proton plans are technically feasible while achieving adequate coverage with lower doses delivered to the lungs and cardiac structures. This may result in decreased cardiopulmonary toxicity and less morbidity to esophageal cancer patients.

  11. Advances in 4D radiation therapy for managing respiration: part II - 4D treatment planning.

    Science.gov (United States)

    Rosu, Mihaela; Hugo, Geoffrey D

    2012-12-01

    The development of 4D CT imaging technology made possible the creation of patient models that are reflective of respiration-induced anatomical changes by adding a temporal dimension to the conventional 3D, spatial-only, patient description. This had opened a new venue for treatment planning and radiation delivery, aimed at creating a comprehensive 4D radiation therapy process for moving targets. Unlike other breathing motion compensation strategies (e.g. breath-hold and gating techniques), 4D radiotherapy assumes treatment delivery over the entire respiratory cycle - an added bonus for both patient comfort and treatment time efficiency. The time-dependent positional and volumetric information holds the promise for optimal, highly conformal, radiotherapy for targets experiencing movements caused by respiration, with potentially elevated dose prescriptions and therefore higher cure rates, while avoiding the uninvolved nearby structures. In this paper, the current state of the 4D treatment planning is reviewed, from theory to the established practical routine. While the fundamental principles of 4D radiotherapy are well defined, the development of a complete, robust and clinically feasible process still remains a challenge, imposed by limitations in the available treatment planning and radiation delivery systems. Copyright © 2012. Published by Elsevier GmbH.

  12. Advances in 4D Radiation Therapy for Managing Respiration: Part II – 4D Treatment Planning

    Science.gov (United States)

    Rosu, Mihaela; Hugo, Geoffrey D.

    2014-01-01

    The development of 4D CT imaging technology made possible the creation of patient models that are reflective of respiration-induced anatomical changes by adding a temporal dimension to the conventional 3D, spatial-only, patient description. This had opened a new venue for treatment planning and radiation delivery, aimed at creating a comprehensive 4D radiation therapy process for moving targets. Unlike other breathing motion compensation strategies (e.g. breath-hold and gating techniques), 4D radiotherapy assumes treatment delivery over the entire respiratory cycle – an added bonus for both patient comfort and treatment time efficiency. The time-dependent positional and volumetric information holds the promise for optimal, highly conformal, radiotherapy for targets experiencing movements caused by respiration, with potentially elevated dose prescriptions and therefore higher cure rates, while avoiding the uninvolved nearby structures. In this paper, the current state of the 4D treatment planning is reviewed, from theory to the established practical routine. While the fundamental principles of 4D radiotherapy are well defined, the development of a complete, robust and clinically feasible process still remains a challenge, imposed by limitations in the available treatment planning and radiation delivery systems. PMID:22796324

  13. Pelvic nodal dose escalation with prostate hypofractionation using conformal avoidance defined (H-CAD) intensity modulated radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Theodore S.; Tome, Wolfgang A.; Jaradat, Hazim; Raisbeck, Bridget M.; Ritter, Mark A. [Univ. of Wisconsin Medical School, Madison, WI (United States). Dept. of Human Oncology

    2006-09-15

    % of both the PTV 70 (prostate) and PTV 56 (nodes). The EUDs for PTV 70 and PTV 56 were greater than prescription dose for all eight plans. Analysis of bio-effective DVHs demonstrated similar amounts of small bowel receiving >45 Gy for H-CAD and sequential plans, in spite of the significantly higher dose to which H-CAD treated the pelvic nodes. The treatment was well tolerated in the eight treated patients in that no grade 2 or higher acute gastrointestinal toxicities were seen. Prostate hypofractionation with concurrent conformal avoidance-based pelvic IMRT for high risk prostate cancer represents an efficient and promising method for achieving dose escalation both of pelvic lymph nodes and the prostate with modest acute toxicity. Unlike a vascular-guided targeting approach, conformal avoidance has the potential advantage of also encompassing at-risk nodes that are not contained within major nodal chains. A phase II trial to more thoroughly examine this treatment approach is currently underway.

  14. A dosimetric comparison of 3D conformal vs intensity modulated vs volumetric arc radiation therapy for muscle invasive bladder cancer

    Directory of Open Access Journals (Sweden)

    Foroudi Farshad

    2012-07-01

    Full Text Available Abstract Background To compare 3 Dimensional Conformal radiotherapy (3D-CRT with Intensity Modulated Radiotherapy (IMRT with Volumetric-Modulated Arc Therapy (VMAT for bladder cancer. Methods Radiotherapy plans for 15 patients with T2-T4N0M0 bladder cancer were prospectively developed for 3-DCRT, IMRT and VMAT using Varian Eclipse planning system. The same radiation therapist carried out all planning and the same clinical dosimetric constraints were used. 10 of the patients with well localised tumours had a simultaneous infield boost (SIB of the primary tumour planned for both IMRT and VMAT. Tumour control probabilities and normal tissue complication probabilities were calculated. Results Mean planning time for 3D-CRT, IMRT and VMAT was 30.0, 49.3, and 141.0 minutes respectively. The mean PTV conformity (CI index for 3D-CRT was 1.32, for IMRT 1.05, and for VMAT 1.05. The PTV Homogeneity (HI index was 0.080 for 3D-CRT, 0.073 for IMRT and 0.086 for VMAT. Tumour control and normal tissue complication probabilities were similar for 3D-CRT, IMRT and VMAT. The mean monitor units were 267 (range 250–293 for 3D-CRT; 824 (range 641–1083 for IMRT; and 403 (range 333–489 for VMAT (P  Conclusions VMAT is associated with similar dosimetric advantages as IMRT over 3D-CRT for muscle invasive bladder cancer. VMAT is associated with faster delivery times and less number of mean monitor units than IMRT. SIB is feasible in selected patients with localized tumours.

  15. An investigation on the radiation sensitivity of DNA conformations to {sup 60}Co gamma rays by using Geant4 toolkit

    Energy Technology Data Exchange (ETDEWEB)

    Semsarha, F. [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Goliaei, B., E-mail: goliaei@ibb.ut.ac.ir [Institute of Biochemistry and Biophysics (IBB), University of Tehran, P.O. Box 13145-1384, Tehran (Iran, Islamic Republic of); Raisali, G.; Khalafi, H. [Radiation Applications Research School, Nuclear Science and Technology Research Institute, P.O. Box 11365-3486, Tehran (Iran, Islamic Republic of); Mirzakhanian, L. [Medical Physics Unit, McGill University, 1650 Cedar Avenue, Montreal, Quebec (Canada)

    2014-03-15

    To investigate the impact of conformational properties of genetic material of living cells on radiation-induced DNA damage, single strand breaks (SSB), double strand breaks (DSB) and some microdosimetric quantities of A, B and Z-DNA conformations caused by {sup 60}Co gamma rays, have been calculated. Based on a previous B-DNA geometrical model, models of A and Z forms have been developed. Simple 34 base pairs segments of each model repeated in high number and secondary electron spectrum of {sup 60}Co gamma rays have been simulated in a volume of a typical animal cell nucleus. All simulations in this study have been performed by using the Geant4 (GEometry ANd Tracking 4)-DNA extension of the Geant4 toolkit. The results showed that, B-DNA has the lowest yield of simple strand breaks with 2.23 × 10{sup −10} Gy{sup −1} Da{sup −1} and 1.0 × 10{sup −11} Gy{sup −1} Da{sup −1} for the SSB and DSB damage yield, respectively. The A-DNA has the highest SSB yield with 3.59 × 10{sup −10} Gy{sup −1} Da{sup −1} and the Z-DNA has the highest DSB yields with 1.8 × 10{sup −11} Gy{sup −1} Da{sup −1}. It has been concluded that there is a direct correlation between the hit probability, mean specific imparted energy and SSB yield in each model of DNA. Moreover, there is a direct correlation between the DSB yield and both the mean lineal energy and topological characteristics of each model.

  16. Statistical Decision Theory Applied to Radiation Therapy Treatment Decisions

    OpenAIRE

    Schultheiss, T. E.; El-Mahdi, Anas M.

    1982-01-01

    Statistical decision theory has been applied to the treatment planning decision of radiation therapy. The decision involves the choice of parameters which determine the radiation dose distribution. To choose among dose distributions requires a decision rule which reflects the uncertainty of possible outcomes for any specific dose distribution and the various risks associated with each outcome. A relative gravity or morbidity is assigned to each possible complication of treatment. In this stud...

  17. MINERVA - A Multi-Modal Radiation Treatment Planning System

    Energy Technology Data Exchange (ETDEWEB)

    D. E. Wessol; C. A. Wemple; D. W. Nigg; J. J. Cogliati; M. L. Milvich; C. Frederickson; M. Perkins; G. A. Harkin

    2004-10-01

    Recently, research efforts have begun to examine the combination of BNCT with external beam photon radiotherapy (Barth et al. 2004). In order to properly prepare treatment plans for patients being treated with combinations of radiation modalities, appropriate planning tools must be available. To facilitiate this, researchers at the Idaho National Engineering and Environmental Laboratory (INEEL)and Montana State University (MSU) have undertaken development of a fully multi-modal radiation treatment planning system.

  18. Interobserver comparison of CT and MRI-based prostate apex definition. Clinical relevance for conformal radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Wachter, S.; Wachter-Gerstner, N.; Goldner, G.; Poetter, R. [University Hospital Vienna (Austria). Dept. of Radiotherapy and Radiobiology; Bock, T. [University Hospital Vienna (Austria). Dept. of Radiotherapy and Radiobiology; University Hospital Kiel (Germany). Interdisziplinary Center of Brachytherapy; Kovacs, G. [University Hospital Kiel (Germany). Interdisziplinary Center of Brachytherapy; Fransson, A. [University Hospital Vienna (Austria). Dept. of Radiotherapy and Radiobiology; Karolinska Hospital, Stockholm (Sweden). Dept. of Hospital

    2002-05-01

    Background: CT is widely used for conformal radiotherapy treatment planning of prostate carcinoma. Its limitations are especially at the prostatic apex which cannot be separated from the urogenital diaphragm. The aim of this study was to compare the localization of the prostatic apex in CT and axial MRI to the sagittal MRI in an interobserver analysis. Patients and Methods: 22 patients with pathologically proven prostatic carcinoma were included in the analysis. In all patients sagittal and axial T2-weighted MRI and conventional CT were performed. The position of the MRI and CT apices were localized independently by three observers in relation to the intertrochanteric line. Additional subjective judgement of the ability to define the apical border of the prostatic gland was performed by a five-scaled score. Results: The apex of the prostate could be discriminated statistically significant (p<0.001) better in the MRI as compared to CT with best judgement for the sagittal MRI. The interobserver variation for the definition of the prostatic apex was statistically significant (p=0.009) smaller for the sagittal MRI compared to axial MRI and CT. On the average the apex as determined by sagittal MRI, axial MRI and CT was located 29 mm, 27 mm and 24 mm above the intertrochanteric line. The apex defined by CT would have led to an additional treatment of 6-13 mm in 10/22 patients compared to the sagittal MRI, defined by axial MRI only in five patients. Conclusion: Additional MRI provides a superior anatomic information especially in the apical portion of the prostate. It should be recommended for every single patient in the treatment planning process. It helps to avoid an unnecessary irradiation of healthy tissue and could lead to a decrease of anal side effects and radiation-induced impotency due to a reduction of the extent of irradiated penile structures. (orig.)

  19. Conformal radiation therapy with hadron beams and the programs of the TERA Foundation.

    Science.gov (United States)

    Amaldi, U

    1998-01-01

    Proposed fifty years ago, tumor therapy with charged hadron beams has been under rapid development since 1993-94. Indeed hadrontherapy was born in 1938, when neutron beams have been used in cancer therapy, but it has become an accepted therapeutical modality only in the last five years. Fast neutrons are still in use, even if their limitations are now apparent. Charged hadron beams are more favorable, since the largest specific energy deposition occurs at the end of their range in matter. The most used hadrons are at present protons and carbon ions. Both allow a dose deposition which conforms to the tumor target. Radiobiology experiments and the results of the first clinical trials indicate that carbon ions have, on top of this macroscopic property, a different way of interacting with cells at the microscopic level. There are thus solid hopes to use carbon beams of about 4500 MeV to control tumors which are radioresistant both to X-rays and protons. After discussing these macroscopic and microscopic properties of hadrontherapy, the twelve dedicated hadrontherapy centres, which will be treating patients from 2001-2002, are shortly described. Five of them are in the USA and seven in Japan, while no hospital based centre for deep protontherapy is fully financed in Europe. The second part of this review is devoted to the Italian hadrontherapy programme, based on the development of the network RITA, the construction in Rome by the "Istituto Superiore di Sanità" of a novel proton accelerator based on a 3 GHz linac, the design of a linac to boost the energy of protons extracted from a 50-70 MeV cyclotron and the construction in Mirasole, near Milano, of a center for protons and ions known as "CNAO". This center will have a synchrotron, which is under design at CERN in the framework of a collaboration of TERA with AUSTRON and GSI which is called PIMMS (Proton Ion Medical Machine Study) and is headed by Dr. Phyl Bryant.

  20. Radiotherapy of intensity modulated VS conformational in the treatment of carcinoma of the prostate. A dosimetric comparison; Radioterapia de intensidad modulada VS conformacional en el tratamiento de carcinoma de prostata. Una camparacion dosimetrica

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Martin, G.; Garcia Vicente, F.; Zapatero Laborda, A.; Bermudez Luna, R.; Roch Gonzalez, M.; Perez Gonzalez, L.; Torres Escobar, J. J.

    2013-07-01

    The intensity modulated (IMRT) radiation therapy is a technique of high conformation which, by its nature, has as one of its main directions prostate cancer radiotherapy treatment. The purpose of this work is presents results of the dosimetric indicators collected in our hospital a number of patients of carcinoma of the prostate with standard three-dimensional Conformal technique (3D-CRT) and IMRT. Aims to demonstrate and quantify with a statistical methodology that, establishing an adequate Protocol of IMRT, significant reductions in risk organ doses can be obtained by keeping the same prescription to the white volume. (Author)

  1. Challenges With the Diagnosis and Treatment of Cerebral Radiation Necrosis

    Energy Technology Data Exchange (ETDEWEB)

    Chao, Samuel T., E-mail: chaos@ccf.org [Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-oncology Center, Cleveland Clinic, Cleveland, Ohio (United States); Ahluwalia, Manmeet S. [Department of Medical Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-oncology Center, Cleveland Clinic, Cleveland, Ohio (United States); Barnett, Gene H. [Department of Neurosurgery, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-oncology Center, Cleveland Clinic, Cleveland, Ohio (United States); Stevens, Glen H.J. [Department of Neurology, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-oncology Center, Cleveland Clinic, Cleveland, Ohio (United States); Murphy, Erin S. [Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-oncology Center, Cleveland Clinic, Cleveland, Ohio (United States); Stockham, Abigail L. [Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Shiue, Kevin [Case Western Reserve University School of Medicine, Cleveland, Ohio (United States); Suh, John H. [Department of Radiation Oncology, Cleveland Clinic, Cleveland, Ohio (United States); Rose Ella Burkhardt Brain Tumor and Neuro-oncology Center, Cleveland Clinic, Cleveland, Ohio (United States)

    2013-11-01

    The incidence of radiation necrosis has increased secondary to greater use of combined modality therapy for brain tumors and stereotactic radiosurgery. Given that its characteristics on standard imaging are no different that tumor recurrence, it is difficult to diagnose without use of more sophisticated imaging and nuclear medicine scans, although the accuracy of such scans is controversial. Historically, treatment had been limited to steroids, hyperbaric oxygen, anticoagulants, and surgical resection. A recent prospective randomized study has confirmed the efficacy of bevacizumab in treating radiation necrosis. Novel therapies include using focused interstitial laser thermal therapy. This article will review the diagnosis and treatment of radiation necrosis.

  2. Effects of Pulsed Electric Field (PEF) Treatment on Enhancing Activity and Conformation of α-Amylase.

    Science.gov (United States)

    Tian, Mei-ling; Fang, Ting; Du, Mu-ying; Zhang, Fu-sheng

    2016-04-01

    To explore an efficient, safe, and speedy application of pulsed electric field (PEF) technology for enzymatic modification, effects of PEF treatment on the enzymatic activity, property and kinetic parameters of α-amylase were investigated. Conformational transitions were also studied with the aid of circular dichroism (CD) and fluorescence spectra. The maximum enzymatic activity of α-amylase was obtained under 15 kV/cm electric field intensity and 100 mL/min flow velocity PEF treatment, in which the enzymatic activity increased by 22.13 ± 1.14% compared with control. The activation effect could last for 18 h at 4 °C. PEF treatment could widen the range of optimum temperature for α-amylase, however, it barely exerted any effect on the optimum pH. On the other hand, α-amylase treated by PEF showed an increase of Vmax, t1/2 and ΔG, whereas a decrease of Km and k were observed. Furthermore, it can be observed from fluorescence and CD spectra that PEF treatment had increased the number of amino acid residues, especially that of tryptophan, on α-amylase surface with enhanced α-helices by 34.76% and decreased random coil by 12.04% on α-amylase when compared with that of untreated. These changes in structure had positive effect on enhancing α-amylase activity and property.

  3. Hypo-Fractionated Conformal Radiation Therapy to the Tumor Bed after Segmental Mastectomy

    Science.gov (United States)

    2007-07-01

    at least 50 patients are available for carnation after 24 months from treatment (based on our original design, with a planned accrual )f 99...target volume (PTV) demonstrated; tumor bed in red vasn. PTV in blue, heart in pink , and lung in light green. PTV represents a 1.5-cm margin on tumor

  4. Insights from radiation treatment for benign disease

    Energy Technology Data Exchange (ETDEWEB)

    Bleehen, N.M.

    1987-08-29

    This note compares mortality figures for patients treated with low dose ionizing radiation for benign conditions between the 1920's and 1950's with figures available from the Japanese A-bomb survivors. X radiation for ringworm, ankylosing spondylitis and post-partum mastitis are considered. Figures for leukemia are roughly comparable between radiotherapy groups and A-bomb survivors. Figures for the increased relative risk of breast cancer in spondylitis patients were in marked contrast to bomb survivors who received comparable doses, but compatible with the increase among women given x-rays for acute post-partum mastitis in the 1940's and 1950's. This study also suggests the possibility of different time patterns of risk between different cancers. (U.K.).

  5. Assessing the quality of conformal treatment planning: a new tool for quantitative comparison

    Energy Technology Data Exchange (ETDEWEB)

    Menhel, J; Levin, D; Alezra, D; Symon, Z; Pfeffer, R [Oncology Institute, Sheba Medical Center, Tel-Hashomer, 52621 (Israel)

    2006-10-21

    We develop a novel radiotherapy plan comparison index, critical organ scoring index (COSI), which is a measure of both target coverage and critical organ overdose. COSI is defined as COSI = 1 - (V(OAR){sub >tol}/TC), where V(OAR){sub >tol} is the fraction of volume of organ at risk receiving more than tolerance dose, and TC is the target coverage, V{sub T,PI}/V{sub T}, where V{sub T,PI} is the target volume receiving at a least prescription dose and V{sub T} is the total target volume. COSI approaches unity when the critical structure is completely spared and the target coverage is unity. We propose a two-dimensional, graphical representation of COSI versus conformity index (CI), where CI is a measure of a normal tissue overdose. We show that this 2D representation is a reliable, visual quantitative tool for evaluating competing plans. We generate COSI-CI plots for three sites: head and neck, cavernous sinus, and pancreas, and evaluate competing non-coplanar 3D and IMRT treatment plans. For all three sites this novel 2D representation assisted the physician in choosing the optimal plan, both in terms of target coverage and in terms of critical organ sparing. We verified each choice by analysing individual DVHs and isodose lines. Comparing our results to the widely used conformation number, we found that in all cases where there were discrepancies in the choice of the best treatment plan, the COSI-CI choice was considered the correct one, in several cases indicating that a non-coplanar 3D plan was superior to the IMRT plans. The choice of plan was quick, simple and accurate using the new graphical representation.

  6. Assessing the quality of conformal treatment planning: a new tool for quantitative comparison.

    Science.gov (United States)

    Menhel, J; Levin, D; Alezra, D; Symon, Z; Pfeffer, R

    2006-10-21

    We develop a novel radiotherapy plan comparison index, critical organ scoring index (COSI), which is a measure of both target coverage and critical organ overdose. COSI is defined as COSI=1-(V(OAR)>tol/TC), where V(OAR)>tol is the fraction of volume of organ at risk receiving more than tolerance dose, and TC is the target coverage, VT,PI/VT, where VT,PI is the target volume receiving at a least prescription dose and VT is the total target volume. COSI approaches unity when the critical structure is completely spared and the target coverage is unity. We propose a two-dimensional, graphical representation of COSI versus conformity index (CI), where CI is a measure of a normal tissue overdose. We show that this 2D representation is a reliable, visual quantitative tool for evaluating competing plans. We generate COSI-CI plots for three sites: head and neck, cavernous sinus, and pancreas, and evaluate competing non-coplanar 3D and IMRT treatment plans. For all three sites this novel 2D representation assisted the physician in choosing the optimal plan, both in terms of target coverage and in terms of critical organ sparing. We verified each choice by analysing individual DVHs and isodose lines. Comparing our results to the widely used conformation number, we found that in all cases where there were discrepancies in the choice of the best treatment plan, the COSI-CI choice was considered the correct one, in several cases indicating that a non-coplanar 3D plan was superior to the IMRT plans. The choice of plan was quick, simple and accurate using the new graphical representation.

  7. Large area radiation source for water and wastewater treatment

    Science.gov (United States)

    Mueller, Michael T.; Lee, Seungwoo; Kloba, Anthony; Hellmer, Ronald; Kumar, Nalin; Eaton, Mark; Rambo, Charlotte; Pillai, Suresh

    2011-06-01

    There is a strong desire for processes that improve the safety of water supplies and that minimize disinfection byproducts. Stellarray is developing mercury-free next-generation x-ray and UV-C radiation sources in flat-panel and pipe form factors for water and wastewater treatment applications. These new radiation sources are designed to sterilize sludge and effluent, and to enable new treatment approaches to emerging environmental concerns such as the accumulation of estrogenic compounds in water. Our UV-C source, based on cathodoluminescent technology, differs significantly from traditional disinfection approaches using mercury arc lamps or UV LEDs. Our sources accelerate electrons across a vacuum gap, converting their energy into UV-C when striking a phosphor, or x-rays when striking a metallic anode target. Stellarray's large area radiation sources for wastewater treatment allow matching of the radiation source area to the sterilization target area for maximum coverage and improved efficiency.

  8. Rapid and Decentralized Human Waste Treatment by Microwave Radiation.

    Science.gov (United States)

    Nguyen, Tu Anh; Babel, Sandhya; Boonyarattanakalin, Siwarutt; Koottatep, Thammarat

    2016-09-07

    This study evaluates the technical feasibility of using microwave radiation for the rapid treatment of human feces. Human feces of 1000 g were radiated with a commercially available household microwave oven (with rotation) at different exposure time lengths (30, 50, 60, 70, and 75 minutes) and powers (600, 800, and 1000 W). Volume reduction over 90% occurred after 1000 W microwave radiation for 75 minutes. Pathogen eradiation performances of six log units or more at a high range of microwave powers were achieved. Treatments with the same energy input of 1000 Wh, but at lower powers with prolonged exposure times, significantly enhanced moisture removal and volume reduction. Microwave radiation caused carbonization and resulted in a more stable end product. The energy content of the samples after microwave treatment at 1000 W and 75 minutes is 3517 ± 8.85 calories/g of dried sample, and the product can also be used as compost.

  9. Hyperbaric oxygen treatment in radiation reactions; Hyperbar oksygenbehandling ved straalereaksjoner

    Energy Technology Data Exchange (ETDEWEB)

    Aanderud, Leif; Thorsen, Einar; Bratteboe, Guttorm; Forland, Martha; Kristensen, Gunnar

    2000-07-01

    Background: A national hyperbaric centre was established in 1994 at Haukeland Hospital with responsibility of all hyperbaric oxygen (HBO) treatment in Norway. In hypoxic tissues with symptomatic radiation reactions, hyperbaric oxygen induces the formation of collagen and angiogenesis resulting in permanently improved local microcirculation. Material and method: 234 patients received elective HBO treatment at Haukeland Hospital in 12997 with total of 4048 treatments. All 47 patients treated for radiation reactions in the pelvic area in 1997 received a questionnaire 3-15 months after HBO therapy, 81% reported. Results: Rectal bleeding and haematuria were reported as much improved in 61% and 55% respectively, while bladder incontinence was much improved in 46%. Interpretation: this treatment modality may be an alternative in symptomatic radiation reactions at the urinary bladder and the bowel when conventional treatment has given unsatisfactory results.

  10. Radiation therapy in the multimodal treatment approach of pituitary adenoma

    Energy Technology Data Exchange (ETDEWEB)

    Becker, G. [Klinik am Eichert, Goeppingen (Germany). Dept. of Radiooncology and Radiation Therapy; Radiooncologic Univ. Clinic, Tuebingen (Germany); Kocher, M.; Mueller, R.P. [Koeln Univ. (Germany). Clinic of Radiation Therapy; Kortmann, R.D.; Paulsen, F.; Jeremic, B.; Bamberg, M. [Radiooncologic Univ. Clinic, Tuebingen (Germany)

    2002-04-01

    In this paper, literature will be reviewed to assess the role of modern radiotherapy and radiosurgery in the management of pituitary adenomas. Material and Methods: Nowadays, magnetic resonance imaging for the definition of the target volume and a real three-dimensional (3-D) treatment planning with field conformation and the possibility for non-coplanar irradiation has to be recommended. Most groups irradiate these benign tumors with single doses of 1.8-2.0 Gy up to a total dose of 45 Gy or 50.4 Gy in extensive parasellar adenomas. Adenomas are mostly small, well circumscribed lesions, and have, therefore, attracted the use of stereotactically guided high-precision irradiation techniques which allow extreme focussing and provide steep dose gradients with selective treatment of the target and optimal protection of the surrounding brain tissue. Results: Radiation therapy controls tumor growth in 80-98% of patients with non-secreting adenomas and 67-89% for endocrine active tumors. Reviewing the recent literature including endocrine active and non-secreting adenomas, irradiated postoperatively or in case of recurrence the 5-, 10- and 15-year local control rates amount 92%, 89% and 79%. In cases of microprolactinoma primary therapy consists of dopamine agonists. Irradiation should be preferred in patients with macroprolactinomas, when drug therapy and/or surgery failed or for patients medically unsuitable for surgery. Reduction and control of prolactin secretion can be achieved in 44-70% of patients. After radiotherapy in acromegaly patients somatomedin-C and growth hormone concentrations decrease to normal levels in 70-90%, with a decrease rate of 10-30% per year. Hypercortisolism is controlled in 50-83% of adults and 80% of children with Cushing's disease, generally in less than 9 months. Hypopituitarism is the most common side effect of pituitary irradiation with an incidence of 13-56%. Long-term overall risk for brain necrosis in a total of 1,388 analyzed

  11. Impact of Gemcitabine Chemotherapy and 3-Dimensional Conformal Radiation Therapy/5-Fluorouracil on Quality of Life of Patients Managed for Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Short, Michala [Discipline of Medical Radiation Sciences, University of Sydney, Sydney, New South Wales (Australia); Western Australia Centre for Cancer and Palliative Care/Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia (Australia); Goldstein, David [Department of Medical Oncology, Prince of Wales Hospital, Sydney, New South Wales (Australia); Halkett, Georgia [Western Australia Centre for Cancer and Palliative Care/Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia (Australia); Reece, William [Covance Asia Pacific, Sydney, New South Wales (Australia); Borg, Martin [Adelaide Radiotherapy Centre, Adelaide, South Australia (Australia); Zissiadis, Yvonne [Department of Radiation Oncology, Royal Perth Hospital, Perth, Western Australia (Australia); Kneebone, Andrew [Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Spry, Nigel, E-mail: Nigel.Spry@health.wa.gov.au [Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Western Australia (Australia); Faculty of Medicine, University of Western Australia, Perth, Western Australia (Australia)

    2013-01-01

    Purpose: To report quality of life (QOL) results for patients receiving chemoradiation therapy for pancreatic cancer. Methods and Materials: Eligible patients (n=41 locally advanced, n=22 postsurgery) entered the B9E-AY-S168 study and received 1 cycle of induction gemcitabine (1000 mg/m{sup 2} weekly Multiplication-Sign 3 with 1-week break) followed by 3-dimensional conformal radiation therapy (RT) (54 Gy locally advanced and 45 Gy postsurgery) and concomitant continuous-infusion 5-fluorouracil (5FU) (200 mg/m{sup 2}/d throughout RT). After 4 weeks, patients received an additional 3 cycles of consolidation gemcitabine chemotherapy. Patients completed the European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-PAN26 questionnaires at baseline, before RT/5FU, at end of RT/5FU, before consolidation gemcitabine, and at treatment completion. Results: The patterns of change in global QOL scores differed between groups. In the locally advanced group global QOL scores were +13, +8, +3, and +1 compared with baseline before RT/5FU (P=.008), at end of RT/5FU, before consolidation gemcitabine, and at treatment completion, respectively. In the postsurgery group, global QOL scores were -3, +4, +15, and +17 compared with baseline at the same time points, with a significant improvement in global QOL before consolidation gemcitabine (P=.03). No significant declines in global QOL were reported by either cohort. Conclusions: This study demonstrates that global QOL and associated function and symptom profiles for pancreatic chemoradiation therapy differ between locally advanced and postsurgery patients, likely owing to differences in underlying disease status. For both groups, the treatment protocol was well tolerated and did not have a negative impact on patients' global QOL.

  12. Impact of jaw position on sparing organs at risk in 3-dimensional conformal radiation therapy of pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Nava Paudel

    2016-03-01

    Full Text Available Purpose: The objective of this work is to investigate the impact of collimator jaw position on dose to organs at risk (OARs during a 3-dimensional conformal radiotherapy (3DCRT of pancreatic cancer and postulate a method to minimize OAR dose by proper positioning of the jaws.Methods: Clinically delivered 3DCRT treatment plans for 10 patients optimized with multiple static beams using multileaf collimator (MLC leaves conformed to a block margin around target, and collimator jaws aligned with outer extent of the block margin were selected. Subsequent plans were generated by displacing the collimator jaws outward in lateral, superior-inferior or both directions by 1 and 2 cm without altering the MLC position. Computed dose to OARs and target with unaltered dose normalization were compared against the corresponding dose obtained from the original plans.Results: Outward displacement of the collimator jaws by 1 cm in lateral and/or superior-inferior direction resulted in a significant increase in mean dose to the studied OARs. The increase was found to be proportional to the outward displacement of the jaws. The increase in maximum dose to spinal cord was significant in a few patients while it was insignificant for all other OARs.Conclusion: Collimator jaws aligned with outer extent of a block margin minimize dose to OARs. Any gap between the block margin and the collimator jaws can lead to an inadvertent delivery of higher dose to the OARs. Hence, the use of an optimal jaw position during treatment planning becomes important to all patient plans.

  13. Stereotactic Ablative Body Radiation Therapy for Primary Kidney Cancer: A 3-Dimensional Conformal Technique Associated With Low Rates of Early Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Pham, Daniel, E-mail: daniel.pham@petermac.org [Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Victoria (Australia); Thompson, Ann [Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Kron, Tomas [Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne, Victoria (Australia); Foroudi, Farshad [Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne, Victoria (Australia); Department of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Kolsky, Michal Schneider [Department of Medical Imaging and Radiation Sciences, Monash University, Melbourne, Victoria (Australia); Devereux, Thomas; Lim, Andrew [Department of Radiotherapy Services, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia); Siva, Shankar [Sir Peter MacCallum Department of Oncology, Melbourne University, Melbourne, Victoria (Australia); Department of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria (Australia)

    2014-12-01

    Purpose: To describe our 3-dimensional conformal planning approaches and report early toxicities with stereotactic body radiation therapy for the management of primary renal cell carcinoma. Methods and Materials: This is an analysis of a phase 1 trial of stereotactic body radiation therapy for primary inoperable renal cell carcinoma. A dose of 42 Gy/3 fractions was prescribed to targets ≥5 cm, whereas for <5 cm 26 Gy/1 fraction was used. All patients underwent a planning 4-dimensional CT to generate a planning target volume (PTV) from a 5-mm isotropic expansion of the internal target volume. Planning required a minimum of 8 fields prescribing to the minimum isodose surrounding the PTV. Intermediate dose spillage at 50% of the prescription dose (R50%) was measured to describe the dose gradient. Early toxicity (<6 months) was scored using the Common Terminology Criteria for Adverse Events (v4.0). Results: From July 2012 to August 2013 a total of 20 patients (median age, 77 years) were recruited into a prospective clinical trial. Eleven patients underwent fractionated treatment and 9 patients a single fraction. For PTV targets <100 cm{sup 3} the median number of beams used was 8 (2 noncoplanar) to achieve an average R50% of 3.7. For PTV targets >100 cm{sup 3} the median beam number used was 10 (4 noncoplanar) for an average R50% value of 4.3. The R50% was inversely proportional to decreasing PTV volume (r=−0.62, P=.003) and increasing total beams used (r=−0.51, P=.022). Twelve of 20 patients (60%) suffered grade ≤2 early toxicity, whereas 8 of 20 patients (40%) were asymptomatic. Nausea, chest wall pain, and fatigue were the most common toxicities reported. Conclusion: A 3-dimensional conformal planning technique of 8-10 beams can be used to deliver highly tolerable stereotactic ablation to primary kidney targets with minimal early toxicities. Ongoing follow-up is currently in place to assess long-term toxicities and cancer control.

  14. Rapid Arc, helical tomotherapy, sliding window intensity modulated radiotherapy and three dimensional conformal radiation for localized prostate cancer: A dosimetric comparison

    Directory of Open Access Journals (Sweden)

    Rajesh A Kinhikar

    2014-01-01

    Full Text Available Objective: The objective of this study was to investigate the potential role of RapidArc (RA compared with helical tomotherapy (HT, sliding window intensity modulated radiotherapy (SW IMRT and three-dimensional conformal radiation therapy (3D CRT for localized prostate cancer. Materials and Methods: Prescription doses ranged from 60 Gy to planning target volume (PTV and 66.25 Gy for clinical target volume prostate (CTV-P over 25-30 fractions. PTV and CTV-P coverage were evaluated by conformity index (CI and homogeneity index (HI. Organ sparing comparison was done with mean doses to rectum and bladder. Results: CI 95 were 1.0 ± 0.01 (RA, 0.99 ± 0.01 (HT, 0.97 ± 0.02 (IMRT, 0.98 ± 0.02 (3D CRT for PTV and 1.0 ± 0.00 (RA, HT, SW IMRT and 3D CRT for CTV-P. HI was 0.11 ± 0.03 (RA, 0.16 ± 0.08 (HT, 0.12 ± 0.03 (IMRT, 0.06 ± 0.01 (3D CRT for PTV and 0.03 ± 0.00 (RA, 0.05 ± 0.01 (HT, 0.03 ± 0.01 (SW IMRT and 3D CRT for CTV-P. Mean dose to bladder were 23.68 ± 13.23 Gy (RA, 24.55 ± 12.51 Gy (HT, 19.82 ± 11.61 Gy (IMRT and 23.56 ± 12.81 Gy (3D CRT, whereas mean dose to rectum was 36.85 ± 12.92 Gy (RA, 33.18 ± 11.12 Gy (HT, IMRT and 38.67 ± 12.84 Gy (3D CRT. Conclusion: All studied intensity-modulated techniques yield treatment plans of significantly improved quality when compared with 3D CRT, with HT providing best organs at risk sparing and RA being the most efficient treatment option, reducing treatment time to 1.45-3.7 min and monitor unit to <400 for a 2 Gy fraction.

  15. A comparative analysis of 3D conformal deep inspiratory–breath hold and free-breathing intensity-modulated radiation therapy for left-sided breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Reardon, Kelli A.; Read, Paul W.; Morris, Monica M. [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Reardon, Michael A. [Department of Radiology, University of Virginia, Charlottesville, VA (United States); Geesey, Constance [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States); Wijesooriya, Krishni, E-mail: kw5wx@hscmail.mcc.virginia.edu [Department of Radiation Oncology, University of Virginia, Charlottesville, VA (United States)

    2013-07-01

    Patients undergoing radiation for left-sided breast cancer have increased rates of coronary artery disease. Free-breathing intensity-modulated radiation therapy (FB-IMRT) and 3-dimensional conformal deep inspiratory–breath hold (3D-DIBH) reduce cardiac irradiation. The purpose of this study is to compare the dose to organs at risk in FB-IMRT vs 3D-DIBH for patients with left-sided breast cancer. Ten patients with left-sided breast cancer had 2 computed tomography scans: free breathing and voluntary DIBH. Optimization of the IMRT plan was performed on the free-breathing scan using 6 noncoplanar tangential beams. The 3D-DIBH plan was optimized on the DIBH scan and used standard tangents. Mean volumes of the heart, the left anterior descending coronary artery (LAD), the total lung, and the right breast receiving 5% to 95% (5% increments) of the prescription dose were calculated. Mean volumes of the heart and the LAD were lower (p<0.05) in 3D-DIBH for volumes receiving 5% to 80% of the prescription dose for the heart and 5% for the LAD. Mean dose to the LAD and heart were lower in 3D-DIBH (p≤0.01). Mean volumes of the total lung were lower in FB-IMRT for dose levels 20% to 75% (p<0.05), but mean dose was not different. Mean volumes of the right breast were not different for any dose; however, mean dose was lower for 3D-DIBH (p = 0.04). 3D-DIBH is an alternative approach to FB-IMRT that provides a clinically equivalent treatment for patients with left-sided breast cancer while sparing organs at risk with increased ease of implementation.

  16. Superficial Radiation Therapy for the Treatment of Nonmelanoma Skin Cancers.

    Science.gov (United States)

    McGregor, Sean; Minni, John; Herold, David

    2015-12-01

    Superficial radiation therapy has become more widely available to dermatologists. With the advent of more portable machines, it has become more convenient for dermatology practices to employ in an office-based setting. The goal of this paper is to provide a deeper insight into the role of superficial radiation therapy in dermatology practice and to review the current literature surrounding its use in the treatment of both basal and squamous cell carcinomas.

  17. Hyperbaric oxygen: Primary treatment of radiation-induced hemorrhagic cystitis

    Energy Technology Data Exchange (ETDEWEB)

    Weiss, J.P.; Neville, E.C.

    1989-07-01

    Of 8 patients with symptoms of advanced cystitis due to pelvic radiation treated with hyperbaric oxygen 7 are persistently improved during followup. All 6 patients treated for gross hematuria requiring hospitalization have been free of symptoms for an average of 24 months (range 6 to 43 months). One patient treated for stress incontinence currently is dry despite little change in bladder capacity, implying salutary effect from hyperbaric oxygen on the sphincter mechanism. One patient with radiation-induced prostatitis failed to respond. This experience suggests that hyperbaric oxygen should be considered the primary treatment for patients with symptomatic radiation-induced hemorrhagic cystitis.

  18. SU-E-T-346: Effect of Jaw Position On Dose to Critical Structures in 3-D Conformal Radiotherapy Treatment of Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Paudel, N; Han, E; Liang, X; Morrill, S; Zhang, X; Hardee, M; Penagaricano, J; Ratanatharathorn, V [Vaneerat, University of Arkansas for Medical Sciences, Little Rock, AR (United States)

    2015-06-15

    Purpose: Three-dimensional conformal therapy remains a valid and widely used modality for pancreatic radiotherapy treatment. It usually meets dose constraints on critical structures. However, careful positioning of collimation jaws can reduce dose to the critical structures. Here we investigate the dosimetric effect of jaw position in MLC-based 3-D conformal treatment planning on critical structures. Methods: We retrospectively selected seven pancreatic cancer patients treated with 3-D conformal radiotherapy. We started with treatment plans (Varian Truebeam LINAC, Eclipse TPS, AAA, 18MV) having both x and y jaws aligned with the farthest extent of the block outline (8mm around PTV). Then we subsequently moved either both x-jaws or all x and y jaws outwards upto 3 cm in 1 cm increments and investigated their effect on average and maximum dose to neighboring critical structures keeping the same coverage to treatment volume. Results: Lateral displacement of both x-jaws by 1cm each increased kidney and spleen mean dose by as much as 1.7% and 1.3% respectively and superior inferior displacement increased liver, right kidney, stomach and spleen dose by as much as 2.1%, 2%, 5.2% and 1.6% respectively. Displacement of all x and y-jaws away by 1cm increased the mean dose to liver, right kidney, left kidney, bowels, cord, stomach and spleen by as much as 4.9%, 5.9%, 2.1%, 2.8%, 7.4%, 10.4% and 4.2% respectively. Percentage increase in mean dose due to 2 and 3cm jaw displacement increased almost linearly with the displaced distance. Changes in maximum dose were much smaller (mostly negligible) than the changes in mean dose. Conclusion: Collimation jaw position affects dose mostly to critical structures adjacent to it. Though treatment plans with MLCs conforming the block margin usually meet dose constraints to critical structures, keeping jaws all the way in, to the edge of the block reduces dose to the critical structures during radiation treatment.

  19. Avaliação da resposta bioquímica no câncer inicial de próstata: experiência uninstitucional comparando teleterapia exclusiva ou associada à braquiterapia de alta taxa de dose Evaluation of biochemical response on early prostate cancer: comparison between treatment with external beam radiation alone and in combination with high-dose rate conformal brachytherapy boost

    Directory of Open Access Journals (Sweden)

    Douglas Guedes de Castro

    2004-08-01

    biochemical response in patients with locally advanced prostate cancer treated with external beam radiation therapy alone or in combination with conformal brachytherapy boost. MATERIALS AND METHODS: From November 1997 to January 2000, 74 patients received 45 Gy of pelvic external irradiation and four were treated with high dose rate iridium-192 conformal boost implants of 4 Gy each (BT. These were compared with 29 other patients treated with 45 Gy of pelvic external irradiation followed by a 24 Gy of bilateral ARC boost (RT from October 1996 to February 2000. Some patients received neoadjuvant androgen deprivation therapy. Three-year actuarial biochemical control rates (BC3 and pretreatment biochemical response predictors such as prostate-specific antigen pretreatment (PSAi, Gleason score (GS and clinical stage (CS, were evaluated. RESULTS: Median follow-up was of 25 months for the RT group and 37 months for the BT group. BC3 was 51% versus 73% (p = 0.032 for RT and BT, respectively. Comparisons of biochemical control by treatment group stratified by PSAi showed that BC3 for RT versus BT was 85.7% versus 79.1% (p = 0.76 for PSAi 10 ng/mL, respectively. For patients with GS 6, BC3 was 78% versus 55% (p = 0.58 for RT versus BT, respectively. For patients with CS T2a, BC3 was 73% versus 69% (p = 0.692 for RT versus BT, respectively. The relative risk of biochemical relapse was 2.3 (95% IC: 1.0-5.1 for patients in RT group compared to the BT group. When adjusted for PSAi and GS, the relative risk of biochemical relapse was 2.4 (95% IC: 1.0-5.7. CONCLUSION: The treatment modality was an independent prognostic factor for biochemical relapse, with a significant improvement in the biochemical control with BT. These early results suggest that this treatment was most beneficial in patients with PSAi > 10 ng/mL, CS < T2a and GS < 6.

  20. Radiation therapy in the treatment of metastatic renal cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Onufrey, V.; Mohiuddin, M.

    1985-11-01

    Adenocarcinoma of the kidney is an unusual tumor, both in its biological behavior and in its response to radiation treatment. Historically, these tumors have been considered to be radioresistant, and the role of radiation therapy remains questionable in the primary management of this disease. However, radiation treatment is routinely used in the palliation of metastatic lesions for relief of symptoms. Therefore, we have undertaken a review of our experience in the treatment of this disease to determine the effectiveness of radiation in its palliation. From 1956 to 1981, 125 patients with metastatic lesions from hypernephroma have been treated in the Department of Radiation Therapy at Thomas Jefferson University Hospital. Most patients were referred for relief of bone pain (86), brain metastasis (12), spinal cord compression (9), and soft tissue masses (18). Total doses varied from 2000 rad to a maximum of 6000 rad. Response to treatment was evaluated on the basis of relief of symptoms, either complete, partial or no change. Our results indicate a significantly higher response rate of 65% for total doses equal to or greater than a TDF of 70, as compared to 25% for doses lower than a TDF of 70. No difference in response was observed either for bone or soft tissue metastasis or visceral disease. This leads us to believe that metastatic lesions from adenocarcinomas of the kidney should be treated to higher doses to obtain maximum response rates. Analysis of these results are presented in detail.

  1. Size reduction and radiation pattern shaping of multi-fed DCC slot antennas used in conformal microwave array hyperthermia applicators.

    Science.gov (United States)

    Maccarini, Paolo F; Arunachalam, Kavitha; Martins, Carlos D; Stauffer, Paul R

    2009-02-23

    The use of conformal antenna array in the treatment of superficial diseases can significantly increase patient comfort while enhancing the local control of large treatment area with irregular shapes. Originally a regular square multi-fed slot antenna (Dual Concentric Conductor - DCC) was proposed as basic unit cell of the array. The square DCC works well when the outline of the treatment area is rectangular such as in the main chest or back area but is not suitable to outline diseases spreading along the armpit and neck area. In addition as the area of the patch increases, the overall power density decreases affecting the efficiency and thus the ability to deliver the necessary thermal dose with medium power amplifier (antennas is preferable as the disease is more accurately contoured and the lower power requirement for the amplifiers correlates with system reliability, durability, linearity and overall reduced cost. For such reason we developed a set of design rules for multi-fed slot antennas with irregular contours and we implemented a design that reduce the area while increasing the perimeter of the slot, thus increasing the antenna efficiency and the power density. The simulation performed with several commercial packages (Ansoft HFSS, Imst Empire, SemcadX and CST Microwave Studio) show that the size reducing method can be applied to several shapes and for different frequencies. The SAR measurements of several DCCs are performed using an in-house high resolution scanning system with tumor equivalent liquid phantom both at 915 MHz for superficial hyperthermia systems in US) and 433 MHz (Europe). The experimental results are compared with the expected theoretical predictions and both simulated and measured patterns of single antennas of various size and shapes are then summed in various combinations using Matlab to show possible treatment irregular contours of complex diseases. The local control is expected to significantly improve while maintaining the patient

  2. The Effect of Flattening Filter Free on Three-dimensional Conformal Radiation Therapy (3D-CRT), Intensity-Modulated Radiation Therapy (IMRT), and Volumetric Modulated Arc Therapy (VMAT) Plans for Metastatic Brain Tumors from Non-small Cell Lung Cancer.

    Science.gov (United States)

    Shi, Li-Wan; Lai, You-Qun; Lin, Qin; Ha, Hui-Ming; Fu, Li-Rong

    2015-07-01

    Flattening filter free (FFF) may affect outcome measures of radiotherapy. The objective of this study is to compare the dosimetric parameters in three types of radiotherapy plans, three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), and volumetric modulated arc therapy (VMAT), with or without the flattening filter (FF), developed for the treatment of metastatic brain tumors from non-small cell lung cancer (NSCLC). From July 2013 to October 2013, 3D-CRT, IMRT, and VMAT treatment plans were designed using 6 MV and 10 MV, with and without FF, for 10 patients with brain metastasis from NSCLC. The evaluation of the treatment plans included homogeneity index (HI), conformity index (CI), monitor units (MU), mean dose (Dmean), treatment time, and the influence of FFF on volumes. There was no difference in CI or HI between FFF and FF models with 3D-CRT, IMRT, and VMAT plans. At 6 MV, a lower Dmean was seen in the FFF model of 3D-CRT and in the VMAT plan at 10 MV. In the IMRT 6 MV, IMRT 10 MV, and VMAT 10 MV plans, higher MUs were seen in the FFF models. FFF treatments are similar in quality to FF plans, generally lead to more monitor units, and are associated with shorter treatment times. FFF plans ranked by the order of superiority in terms of a time advantage are VMAT, 3D-CRT, and IMRT.

  3. A pilot study of intensity modulated radiation therapy with hypofractionated stereotactic body radiation therapy (SBRT) boost in the treatment of intermediate- to high-risk prostate cancer.

    Science.gov (United States)

    Oermann, Eric K; Slack, Rebecca S; Hanscom, Heather N; Lei, Sue; Suy, Simeng; Park, Hyeon U; Kim, Joy S; Sherer, Benjamin A; Collins, Brian T; Satinsky, Andrew N; Harter, K William; Batipps, Gerald P; Constantinople, Nicholas L; Dejter, Stephen W; Maxted, William C; Regan, James B; Pahira, John J; McGeagh, Kevin G; Jha, Reena C; Dawson, Nancy A; Dritschilo, Anatoly; Lynch, John H; Collins, Sean P

    2010-10-01

    Clinical data suggest that large radiation fractions are biologically superior to smaller fraction sizes in prostate cancer radiotherapy. The CyberKnife is an appealing delivery system for hypofractionated radiosurgery due to its ability to deliver highly conformal radiation and to track and adjust for prostate motion in real-time. We report our early experience using the CyberKnife to deliver a hypofractionated stereotactic body radiation therapy (SBRT) boost to patients with intermediate- to high-risk prostate cancer. Twenty-four patients were treated with hypofractionated SBRT and supplemental external radiation therapy plus or minus androgen deprivation therapy (ADT). Patients were treated with SBRT to a dose of 19.5 Gy in 3 fractions followed by intensity modulated radiation therapy (IMRT) to a dose of 50.4 Gy in 28 fractions. Quality of life data were collected with American Urological Association (AUA) symptom score and Expanded Prostate Cancer Index Composite (EPIC) questionnaires before and after treatment. PSA responses were monitored; acute urinary and rectal toxicities were assessed using Common Toxicity Criteria (CTC) v3. All 24 patients completed the planned treatment with an average follow-up of 9.3 months. For patients who did not receive ADT, the median pre-treatment PSA was 10.6 ng/ml and decreased in all patients to a median of 1.5 ng/ml by 6 months post-treatment. Acute effects associated with treatment included Grade 2 urinary and gastrointestinal toxicity but no patient experienced acute Grade 3 or greater toxicity. AUA and EPIC scores returned to baseline by six months post-treatment. Hypofractionated SBRT combined with IMRT offers radiobiological benefits of a large fraction boost for dose escalation and is a well tolerated treatment option for men with intermediate- to high-risk prostate cancer. Early results are encouraging with biochemical response and acceptable toxicity. These data provide a basis for the design of a phase II clinical

  4. Five-Year Outcomes, Cosmesis, and Toxicity With 3-Dimensional Conformal External Beam Radiation Therapy to Deliver Accelerated Partial Breast Irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Rodríguez, Núria, E-mail: nrodriguez@parcdesalutmar.cat [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Sanz, Xavier [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Dengra, Josefa [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Foro, Palmira [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Membrive, Ismael; Reig, Anna [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Quera, Jaume [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain); Fernández-Velilla, Enric; Pera, Óscar; Lio, Jackson; Lozano, Joan [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Algara, Manuel [Department of Radiation Oncology, Hospital de la Esperanza, Parc de Salut MAR, Barcelona (Spain); Universidad Pompeu Fabra, Barcelona (Spain)

    2013-12-01

    Purpose: To report the interim results from a study comparing the efficacy, toxicity, and cosmesis of breast-conserving treatment with accelerated partial breast irradiation (APBI) or whole breast irradiation (WBI) using 3-dimensional conformal external beam radiation therapy (3D-CRT). Methods and Materials: 102 patients with early-stage breast cancer who underwent breast-conserving surgery were randomized to receive either WBI (n=51) or APBI (n=51). In the WBI arm, 48 Gy was delivered to the whole breast in daily fractions of 2 Gy, with or without additional 10 Gy to the tumor bed. In the APBI arm, patients received 37.5 Gy in 3.75 Gy per fraction delivered twice daily. Toxicity results were scored according to the Radiation Therapy Oncology Group Common Toxicity Criteria. Skin elasticity was measured using a dedicated device (Multi-Skin-Test-Center MC-750-B2, CKelectronic-GmbH). Cosmetic results were assessed by the physician and the patients as good/excellent, regular, or poor. Results: The median follow-up time was 5 years. No local recurrences were observed. No significant differences in survival rates were found. APBI reduced acute side effects and radiation doses to healthy tissues compared with WBI (P<.01). Late skin toxicity was no worse than grade 2 in either group, without significant differences between the 2 groups. In the ipsilateral breast, the areas that received the highest doses (ie, the boost or quadrant) showed the greatest loss of elasticity. WBI resulted in a greater loss of elasticity in the high-dose area compared with APBI (P<.05). Physician assessment showed that >75% of patients in the APBI arm had excellent or good cosmesis, and these outcomes appear to be stable over time. The percentage of patients with excellent/good cosmetic results was similar in both groups. Conclusions: APBI delivered by 3D-CRT to the tumor bed for a selected group of early-stage breast cancer patients produces 5-year results similar to those achieved with

  5. Radiation treatment of food. A new technology for preservation

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, K.; Huebner, G.

    1985-09-01

    The brief survey reports on irradiation of food, especially onions, potatoes, chicken meat, spices, additives, and enzyme solutions used in food industries, demonstrating examples from several countries. Advantages, microbiological aspects of irradiation treatment and chemical radiation effects are described. Technological fundamentals of radiopreservation including irradiation plants and devices are outlined.

  6. PET-guided delineation of radiation therapy treatment volumes: a survey of image segmentation techniques

    Energy Technology Data Exchange (ETDEWEB)

    Zaidi, Habib [Geneva University Hospital, Division of Nuclear Medicine, Geneva 4 (Switzerland); Geneva University, Geneva Neuroscience Center, Geneva (Switzerland); El Naqa, Issam [Washington University School of Medicine, Department of Radiation Oncology, St. Louis, MO (United States)

    2010-11-15

    Historically, anatomical CT and MR images were used to delineate the gross tumour volumes (GTVs) for radiotherapy treatment planning. The capabilities offered by modern radiation therapy units and the widespread availability of combined PET/CT scanners stimulated the development of biological PET imaging-guided radiation therapy treatment planning with the aim to produce highly conformal radiation dose distribution to the tumour. One of the most difficult issues facing PET-based treatment planning is the accurate delineation of target regions from typical blurred and noisy functional images. The major problems encountered are image segmentation and imperfect system response function. Image segmentation is defined as the process of classifying the voxels of an image into a set of distinct classes. The difficulty in PET image segmentation is compounded by the low spatial resolution and high noise characteristics of PET images. Despite the difficulties and known limitations, several image segmentation approaches have been proposed and used in the clinical setting including thresholding, edge detection, region growing, clustering, stochastic models, deformable models, classifiers and several other approaches. A detailed description of the various approaches proposed in the literature is reviewed. Moreover, we also briefly discuss some important considerations and limitations of the widely used techniques to guide practitioners in the field of radiation oncology. The strategies followed for validation and comparative assessment of various PET segmentation approaches are described. Future opportunities and the current challenges facing the adoption of PET-guided delineation of target volumes and its role in basic and clinical research are also addressed. (orig.)

  7. Radiation-induced xerostomia: pathophysiology, clinical course and supportive treatment.

    Science.gov (United States)

    Guchelaar, H J; Vermes, A; Meerwaldt, J H

    1997-07-01

    Xerostomia, or oral dryness, is one of the most common complaints experienced by patients who have had radiotherapy of the oral cavity and neck region. The hallmarks of radiation-induced damage are acinar atrophy and chronic inflammation of the salivary glands. The early response, resulting in atrophy of the secretory cells without inflammation might be due to radiation-induced apoptosis. In contrast, the late response with inflammation could be a result of radiation-induced necrosis. The subjective complaint of a dry mouth appears to be poorly correlated with objective findings of salivary gland dysfunction. Xerostomia, with secondary symptoms of increased dental caries, difficulty in chewing, swallowing and speaking, and an increased incidence of oral candidiasis, can have a significant effect on the quality of life. At present there is no causal treatment for radiation-induced xerostomia. Temporary symptomatic relief can be offered by moistening agents and saliva substitutes, and is the only option for patients without residual salivary function. In patients with residual salivary function, oral administration of pilocarpine 5-10 mg three times a day is effective in increasing salivary flow and improving the symptoms of xerostomia, and this therapy should be considered as the treatment of choice. Effectiveness of sialogogue treatment requires residual salivary function, which emphasizes the potential benefit from sparing normal tissue during irradiation. The hypothesis concerning the existence of early apoptotic and late necrotic effects of irradiation on the salivary glands theoretically offers a way of achieving this goal.

  8. Brain radiation necrosis following treatment of an esthesioneuroblastoma (olfactory neurocytoma)

    Energy Technology Data Exchange (ETDEWEB)

    Baron, S.H.

    1979-02-01

    Esthesioneuroblastoma is an uncommon malignant nasal tumor which may be difficult to diagnose. Once diagnosed, selection of treatment may be a dilemma. Some advocate preoperative radiation and surgery; others, surgery and postoperative radiation if needed. A case that developed brain necrosis from postoperative radation is presented. It is felt that the possibility exists that the patient might still be living with tumor had irradiation not been given. This is a plea for the conservative approach to treatment. The author agrees with John S. Lewis that it is unwise to use all modalities at once as there is no definite evidence that any one method of treatment or a combination of surgery and irradiation will alter the prognosis. The paper stresses the brain hazards of irradiation.

  9. SU-E-T-410: Evaluation of Treatment Modalities for Stereotactic Lung Radiation Therapy: A Phantom Study

    Energy Technology Data Exchange (ETDEWEB)

    Mohatt, D; Malhotra, H [Roswell Park Cancer Institute, Buffalo, NY (United States)

    2015-06-15

    Purpose: To evaluate and verify the accuracy of alternative treatment modalities for stereotactic lung therapy with end-to-end testing. We compared three dimensional conformal therapy (3DCRT), dynamic conformal arc therapy (DCAT), intensity modulated radiation therapy (IMRT) and volumetric modulated arc therapy (VMAT) treatment using 6 MV, 6 MV flattening filter free (FFF) and 10 MV FFF photons. Methods: A QUASAR respiratory motion phantom was utilized with custom ion chamber and gafchromatic EBT2 film inserts. The phantom contained a low density lung medium with a cylindrical polystyrene tumor (35 cc). Pseudo representative structures for various organs at risk (OAR) were created. All treatment plans were created using Eclipse ver. 11 using the same image and structure sets, and delivered via Varian TrueBeam STx linear accelerator equipped with high definition MLC. Evaluation of plan quality followed ROTG 0813 criterion for conformity index (CI100%), high dose spillage, D2cm, and R50%. Results: All treatment plans met the OAR dose constraints per protocol and could be delivered without any beam hold offs or other interlocks and hence were deemed clinically safe. For equivalent beam energies, target conformity was improved for all modalities when switching to FFF mode. Treatment efficiency increased for VMAT FFF by a factor of 3–4 over IMRT, and up to factor of 7 when compared to 3DCRT. Pass rates were > 97% for all treatment using gamma criteria of 3%, 3mm. Absolute dose at iso-center was verified with ion chamber, and found to be within 2% of the treatment planning system. Conclusion: The higher dose rate associated with FFF not only reduces delivery times, but in most cases enhances plan quality. The one modality with succeeding best results for all RTOG criterions was VMAT 6 MV FFF. This end-to-end testing provides necessary confidence in the entire dose delivery chain for lung SBRT patients.

  10. Development of computer algorithms for radiation treatment planning.

    Science.gov (United States)

    Cunningham, J R

    1989-06-01

    As a result of an analysis of data relating tissue response to radiation absorbed dose the ICRU has recommended a target for accuracy of +/- 5 for dose delivery in radiation therapy. This is a difficult overall objective to achieve because of the many steps that make up a course of radiotherapy. The calculation of absorbed dose is only one of the steps and so to achieve an overall accuracy of better than +/- 5% the accuracy in dose calculation must be better yet. The physics behind the problem is sufficiently complicated so that no exact method of calculation has been found and consequently approximate solutions must be used. The development of computer algorithms for this task involves the search for better and better approximate solutions. To achieve the desired target of accuracy a fairly sophisticated calculation procedure must be used. Only when this is done can we hope to further improve our knowledge of the way in which tissues respond to radiation treatments.

  11. Late Toxicity and Patient Self-Assessment of Breast Appearance/Satisfaction on RTOG 0319: A Phase 2 Trial of 3-Dimensional Conformal Radiation Therapy-Accelerated Partial Breast Irradiation Following Lumpectomy for Stages I and II Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Chafe, Susan, E-mail: susan.chafe@albertahealthservices.ca [Department of Radiation Oncology, Cross Cancer Institute-University of Alberta, Edmonton, Alberta (Canada); Moughan, Jennifer [Department of Radiation Oncology, RTOG Statistical Center, Philadelphia, Pennsylvania (United States); McCormick, Beryl [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Wong, John [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, Maryland (United States); Pass, Helen [Womens' Breast Center, Stamford Hospital, Stamford, Connecticut (United States); Rabinovitch, Rachel [Department of Radiation Oncology, University of Colorado Denver, Aurora, Colorado (United States); Arthur, Douglas W. [Department of Radiation Oncology, Virginia Commonwealth University, Richmond, Virginia (United States); Petersen, Ivy [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); White, Julia [Department of Radiation Oncology, Ohio State University, Columbus, Ohio (United States); Vicini, Frank A. [Michigan Healthcare Professionals/21st Century Oncology, Farmington Hills, Michigan (United States)

    2013-08-01

    Purpose: Late toxicities and cosmetic analyses of patients treated with accelerated partial breast irradiation (APBI) on RTOG 0319 are presented. Methods and Materials: Patients with stages I to II breast cancer ≤3 cm, negative margins, and ≤3 positive nodes were eligible. Patients received three-dimensional conformal external beam radiation therapy (3D-CRT; 38.5 Gy in 10 fractions twice daily over 5 days). Toxicity and cosmesis were assessed by the patient (P), the radiation oncologist (RO), and the surgical oncologist (SO) at 3, 6, and 12 months from the completion of treatment and then annually. National Cancer Institute Common Terminology Criteria for Adverse Events, version 3.0, was used to grade toxicity. Results: Fifty-two patients were evaluable. Median follow-up was 5.3 years (range, 1.7-6.4 years). Eighty-two percent of patients rated their cosmesis as good/excellent at 1 year, with rates of 64% at 3 years. At 3 years, 31 patients were satisfied with the treatment, 5 were not satisfied but would choose 3D-CRT again, and none would choose standard radiation therapy. The worst adverse event (AE) per patient reported as definitely, probably, or possibly related to radiation therapy was 36.5% grade 1, 50% grade 2, and 5.8% grade 3 events. Grade 3 AEs were all skin or musculoskeletal-related. Treatment-related factors were evaluated to potentially establish an association with observed toxicity. Surgical bed volume, target volume, the number of beams used, and the use of bolus were not associated with late cosmesis. Conclusions: Most patients enrolled in RTOG 0319 were satisfied with their treatment, and all would choose to have the 3D-CRT APBI again.

  12. Comment on genetic and global algorithms for optimization of three-dimensional conformal radiotherapy treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Vaarkamp, Jaap [Joint Department of Physics, Royal Marsden NHS Trust, Sutton, Surrey (United Kingdom). E-mail: jaap@icr.ac.uk

    2001-06-01

    Full text: I would like to make four comments on three papers by two authors (Wu and Zhu 2000, 2001, Wu et al 2000) on one topic: optimization of 3D conformal radiotherapy treatment planning. In the papers, genetic and global algorithms are proposed for this optimization, and the authors claim to be able to generate better treatment plans than those produced manually and used for patient treatment (Wu and Zhu 2000). However, the data in the papers do not warrant such a conclusion and the work contains such serious methodological flaws that only the opposite can have been true. First, in the papers a few treatment plans for patients with different brain tumours are discussed. Dose volume histograms (DVHs) are presented for the target, sometimes the planning target volume, sometimes the clinical target volume, and the organs at risk (OARs): left and right eye, and thyroid or spinal cord. However, other OARs limit dose more in clinical treatment planning, and it is those OARs to which the planner must direct all effort when optimizing the treatment plan. One such important OAR when treating children is the temporal lobes because the dose to the temporal lobes has been associated with a reduction in IQ points (Fuss et al 2000). Also particularly important when treating children are the hypothalamus and pituitary, because they influence growth and the further hormonal development (Schmiegelow et al 1999, 2000). Furthermore, rather than the eyes themselves, the optic chiasm usually gets more serious attention (Fuss et al 1999) and is considered so important that it is often blocked from the treatment fields during the final fractions, thus compromising dose homogeneity in the target. Finally, irradiating the auditory apparatus can lead to a loss of hearing (Lin et al 2000), and, in particular when one side receives a high dose, every effort is made to at least spare the other side. Hence, it is not surprising to find a treatment plan that is superior in some of the

  13. Acupuncture treatment of patients with radiation-induced xerostomia

    Energy Technology Data Exchange (ETDEWEB)

    Blom, M.; Dawidson, I.; Johnson, G.; Angmar-Maansson, B. [Karolinska Inst., Huddinge (Sweden). Dept. of Cardiology; Fernberg, J.-O. [Karolinska Hospital, Stockholm (Sweden). Dept. of General Oncology

    1996-05-01

    Xerostomia is a common and usually irreversible side effect in patients receiving radiation therapy (>50 Gy) for head and neck cancer. Of 38 patients with radiation-induced xerostomia, 20 in the experimental group were treated with classical acupuncture and 18 patients in the control group received superficial acupuncture as placebo. Within both groups the patients showed significantly increased salivary flow rates after the acupuncture treatment. In the experimental group 68% and in the control group 50% of the patients had increased salivary flow rates at the end of the observation period. Among those patients who had had all their salivary glands irradiated, 50% in both groups showed increased salivary flow rates (>20%) by the end of the observation period of 1 year. The study indicates that among the patients who had increased salivary flow rates already after the first 12 acupuncture sessions, the majority had high probability of continual improvement after the completion of acupuncture treatment. (Author).

  14. Treatment of radiation- and chemotherapy-induced stomatitis

    Energy Technology Data Exchange (ETDEWEB)

    Carnel, S.B.; Blakeslee, D.B.; Oswald, S.G.; Barnes, M. (Fitzsimons Army Medical Center, Aurora, CO (USA))

    1990-04-01

    Severe stomatitis is a common problem encountered during either radiation therapy or chemotherapy. Most therapeutic regimens are empirical, with no scientific basis. The purpose of this study is to determine the efficacy of various topical solutions in the treatment of radiation- or chemotherapy-induced stomatitis. Eighteen patients were entered into a prospective double-blinded study to test several topical solutions: (1) viscous lidocaine with 1% cocaine; (2) dyclonine hydrochloride 1.0% (Dyclone); (3) kaolin-pectin solution, diphenhydramine plus saline (KBS); and (4) a placebo solution. Degree of pain relief, duration of relief, side effects, and palatability were evaluated. The results showed that Dyclone provided the most pain relief. Dyclone and viscous lidocaine with 1% cocaine provided the longest pain relief, which averaged 50 minutes This study provides objective data and defines useful guidelines for treatment of stomatitis.

  15. Comparison of geometric uncertainties using electronic portal imaging device in focal three-dimensional conformal radiation therapy using different head supports

    Directory of Open Access Journals (Sweden)

    Budrukkar Ashwini

    2008-01-01

    Full Text Available Aims and Objectives: To study the geometric uncertainties in the treatment and evaluate the adequacy of the margins employed for planning target volume (PTV generation in the treatment of focal conformal radiotherapy (CRT for patients with brain tumors treated with different head support systems. Materials and Methods: The study population included 11 patients with brain tumors who were to be treated with CRT. Contrast-enhanced planning CT scan (5-mm spacing and reconstructed to 2 mm of brain were performed. Five patients were immobilized using neck support only (NR-only and six patients had neck support with flexion (NRF, the form of immobilization being decided by the likely beam arrangements to be employed for that particular patient. The data was transferred to the planning system (CadPlan where three-dimensional conformal radiation therapy was planned. Digitally reconstructed radiographs (DRRs were created for the orthogonal portals with the fixed field sizes of 10 x 10 taken at the isocenter. Treatment verification was done using an amorphous silicon detector portal imaging device for using orthogonal portals and the DRR was used as a reference image. An image matching software was used to match the anatomical landmarks in the DRR and the portal imaging and the displacement of the portals in x, y axis and rotation were noted in the anteroposterior (AP and lateral images. Electronic portal imaging was repeated twice weekly and an average of 8-14 images per patient was recorded. The mean deviation in all the directions was calculated for the each patient. Comparison of setup errors between the two head support systems was done. Results: A total 224 images were studied in anterior and lateral portals. The patient group with NR-only had 100 images, while the NRF group had 124 images. The mean total error in all patients, NR-only group, and NRF group was 0.33 mm, 0.24 mm, and 0.79 mm in the mediolateral (ML direction; 1.16 mm, 0.14 mm, and 2

  16. Gamma radiation induced effects on slaughterhouse wastewater treatment

    Science.gov (United States)

    Melo, Rita; Cabo Verde, Sandra; Branco, Joaquim; Botelho, M. Luisa

    2008-01-01

    A preliminary study using gamma radiation on slaughterhouse wastewater samples was carried out. Chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) results were obtained at a dose rate of 0.9 kGy h -1. A decrease of COD, BOD and colour was observed after irradiation at high absorbed doses. The microbiological results, following irradiation in the same conditions, correlated with the BOD results. The results obtained highlight the potential of this technology for wastewater treatment.

  17. Can radiation therapy treatment planning system accurately predict surface doses in postmastectomy radiation therapy patients?

    Energy Technology Data Exchange (ETDEWEB)

    Wong, Sharon [National University of Singapore, Yong Loo Lin School of Medicine (Singapore); Back, Michael [Northern Sydney Cancer Centre, Royal North Shore Hospital, St Leonards, New South Wales (Australia); Tan, Poh Wee; Lee, Khai Mun; Baggarley, Shaun [National University, Cancer Institute, Department of Radiation Oncology, National University, Hospital, Tower Block (Singapore); Lu, Jaide Jay, E-mail: mdcljj@nus.edu.sg [National University of Singapore, Yong Loo Lin School of Medicine (Singapore); National University, Cancer Institute, Department of Radiation Oncology, National University, Hospital, Tower Block (Singapore)

    2012-07-01

    Skin doses have been an important factor in the dose prescription for breast radiotherapy. Recent advances in radiotherapy treatment techniques, such as intensity-modulated radiation therapy (IMRT) and new treatment schemes such as hypofractionated breast therapy have made the precise determination of the surface dose necessary. Detailed information of the dose at various depths of the skin is also critical in designing new treatment strategies. The purpose of this work was to assess the accuracy of surface dose calculation by a clinically used treatment planning system and those measured by thermoluminescence dosimeters (TLDs) in a customized chest wall phantom. This study involved the construction of a chest wall phantom for skin dose assessment. Seven TLDs were distributed throughout each right chest wall phantom to give adequate representation of measured radiation doses. Point doses from the CMS Xio Registered-Sign treatment planning system (TPS) were calculated for each relevant TLD positions and results correlated. There were no significant difference between measured absorbed dose by TLD and calculated doses by the TPS (p > 0.05 (1-tailed). Dose accuracy of up to 2.21% was found. The deviations from the calculated absorbed doses were overall larger (3.4%) when wedges and bolus were used. 3D radiotherapy TPS is a useful and accurate tool to assess the accuracy of surface dose. Our studies have shown that radiation treatment accuracy expressed as a comparison between calculated doses (by TPS) and measured doses (by TLD dosimetry) can be accurately predicted for tangential treatment of the chest wall after mastectomy.

  18. Nasopharyngeal carcinoma. Treatment planning with IMRT and 3D conformal radiotherapy

    DEFF Research Database (Denmark)

    Kristensen, Claus A; Kjaer-Kristoffersen, Flemming; Sapru, Wendy

    2007-01-01

    The study was undertaken in order to compare dose plans for intensity-modulated radiotherapy (IMRT) with 3D conformal radiotherapy (3D-CRT) dose plans in patients with nasopharyngeal carcinoma (NPC). Clinical data from 20 consecutive patients treated with IMRT are presented. For 11 patients 3D-CR...

  19. WE-G-16A-01: Evolution of Radiation Treatment Planning

    Energy Technology Data Exchange (ETDEWEB)

    Rothenberg, L [Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Mohan, R [UT MD Anderson Cancer Center, Houston, TX (United States); Van Dyk, J [Western University, London, ON (United Kingdom); Fraass, B [Cedars-Sinai Medical Center, Los Angeles, CA (United States); Bortfeld, T [Massachusetts General Hospital, Boston, MA (United States)

    2014-06-15

    , structure delineation, assignment of dose requirements, consideration of uncertainties, selection of beam configurations and shaping of beams, and calculations, optimization and evaluation of dose distributions. This will be followed by three presentations covering the evolution of treatment planning, which parallels the evolution of computers, availability of advanced volumetric imaging and the development of novel technologies such as dynamic multi-leaf collimators and online image guidance. This evolution will be divided over three distinct periods - prior to 1970's, the 2D era; from 1980 to the mid-1990's, the 3D era; and from the mid 1990's to today, the IMRT era. When the World was Flat: The Two-Dimensional Radiation Therapy Era” - Jacob Van Dyk In the 2D era, anatomy was defined with the aid of solder wires, special contouring devices and projection x-rays. Dose distributions were calculated manually from single field, flat surface isodoses on transparencies. Precalculated atlases of generic dose distributions were produced by the International Atomic Energy Agency. Massive time-shared main frames and mini-computers were used to compute doses at individual points or dose distributions in a single plane. Beam shapes were generally rectangular, with wedges, missing tissue compensators and occasional blocks to shield critical structures. Dose calculations were measurement-based or they used primary and scatter calculations based on scatter-air ratio methodologies. Dose distributions were displayed on line printers as alpha-numeric character maps or isodose patterns made with pen plotters. More than Pretty Pictures: 3D Treatment Planning and Conformal Therapy - Benedick A. Fraass The introduction of computed tomography allowed the delineation of anatomy three-dimensionally and, supported partly by contracts from the National Cancer Institute, made possible the introduction and clinical use of 3D treatment planning, leading to development and use of 3D

  20. Usefulness of radiation treatment planning allpied respiration factor for streotatic body radiation therapy in the lung cancer

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Sung Pil; Kim, Tae Hyung; So, Woon Young; Back, Geum Mun [Dept. of Medical Health Science, Graduate School, Kangwon National University, Chuncheon (Korea, Republic of)

    2016-12-15

    We are evaluated the usefulness of radiation treatment planning applied respiration factor for stereotactic body radiation therapy in the lung cancer. Four dimensional computed tomography images were obtained in 10 patients with lung cancer. The radiation treatment plans were established total lung volume according to respiration images (new method) and conventional method. We was analyzed in the lung volume, radiation absorbed dose of lung and main organs (ribs, tracheobronchus, esophagus, spinal cord) around the tumor, respectively. We were confirmed that lung volume and radiation absorbed dose of lung and main organs around the tumor deference according to applied respiration. In conclusion, radiation treatment planning applied respiration factor seems to be useful for stereotactic body radiation therapy in the lung cancer.

  1. Radiation optic neuropathy and retinopathy with low dose (20 Gy radiation treatment

    Directory of Open Access Journals (Sweden)

    Crandall E. Peeler

    2016-10-01

    Conclusions and importance: Though cumulative radiation doses to the anterior visual pathway of less than 50 Gy are traditionally felt to be safe, it is important to consider not just the total exposure but also the size of individual fractions. The single-dose threshold for RON in proton beam treatment has yet to be defined. Our case suggests that fractions of less than 10 Gy should be delivered to minimize the risk of optic nerve injury.

  2. Conformational changes in proteins recovered from jumbo squid (Dosidicus gigas) muscle through pH shift washing treatments.

    Science.gov (United States)

    Cortés-Ruiz, Juan A; Pacheco-Aguilar, Ramón; Ramírez-Suárez, Juan C; Lugo-Sánchez, Maria E; García-Orozco, Karina D; Sotelo-Mundo, Rogerio R; Peña-Ramos, Aida

    2016-04-01

    Conformational and thermal-rheological properties of acidic (APC) and neutral (NPC) protein concentrates were evaluated and compared to those of squid (Dosidicus gigas) muscle proteins (SM). Surface hydrophobicity, sulfhydryl status, secondary structure profile, differential scanning calorimetry and oscillatory dynamic rheology were used to evaluate the effect of treatments on protein properties. Acidic condition during the washing process (APC) promoted structural and conformational changes in the protein present in the concentrate produced. These changes were enhanced during the heat setting of the corresponding sol. Results demonstrate that washing squid muscle under the proposed acidic conditions is a feasible technological alternative for squid-based surimi production improving its yield and gel-forming ability.

  3. Treatment planning and 3D dose verification of whole brain radiation therapy with hippocampal avoidance in rats

    Science.gov (United States)

    Yoon, S. W.; Miles, D.; Cramer, C.; Reinsvold, M.; Kirsch, D.; Oldham, M.

    2017-05-01

    Despite increasing use of stereotactic radiosurgery, whole brain radiotherapy (WBRT) continues to have a therapeutic role in a selected subset of patients. Selectively avoiding the hippocampus during such treatment (HA-WBRT) emerged as a strategy to reduce the cognitive morbidity associated with WBRT and gave rise to a recently published the phase II trial (RTOG 0933) and now multiple ongoing clinical trials. While conceptually hippocampal avoidance is supported by pre-clinical evidence showing that the hippocampus plays a vital role in memory, there is minimal pre-clinic data showing that selectively avoiding the hippocampus will reduce radiation-induced cognitive decline. Largely the lack of pre-clinical evidence can be attributed to the technical hurdles associated with delivering precise conformal treatment the rat brain. In this work we develop a novel conformal HA-WBRT technique for Wistar rats, utilizing a 225kVp micro-irradiator with precise 3D-printed radiation blocks designed to spare hippocampus while delivering whole brain dose. The technique was verified on rodent-morphic Presage® 3D dosimeters created from micro-CT scans of Wistar rats with Duke Large Field-of-View Optical Scanner (DLOS) at 1mm isotropic voxel resolution. A 4-field box with parallel opposed AP-PA and two lateral opposed fields was explored with conformal hippocampal sparing aided by 3D-printed radiation blocks. The measured DVH aligned reasonably well with that calculated from SmART Plan Monte Carlo simulations with simulated blocks for 4-field HA-WBRT with both demonstrating hippocampal sparing of 20% volume receiving less than 30% the prescription dose.

  4. [Treatment of extensive acute radiation burn and its complications].

    Science.gov (United States)

    Li, Ye-yang; Wang, Jin-lun; Li, Gang; Lin, Wei-hua; Liang, Min; Huang, Jun; Sun, Jing-en

    2013-06-01

    This article reports the treatment of a patient suffered from acute radiation burn covering 41% TBSA, with deep partial-thickness and full-thickness injury, produced by exposure to a large-scale industrial electron accelerator. An open wound began to appear and enlarged gradually 10 weeks after the exposure. Serious wound infection with methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa, pneumonia, respiratory failure, systemic inflammatory response syndrome, nephropathy and hypoproteinemia developed successively since 3 weeks after the wound formation. Skin grafts failed to survive, resulting in enlargement of the wound. After being treated with proper measures, including parenteral nutrition, respiratory support with a ventilator, appropriate antibiotics, steroid administration for nephropathy, deep debridement for wounds followed by skin grafting, the patient was cured and discharged after undergoing 15 operations in 500 days. The clinical condition of an extensive acute radiation burn is complicated. We should pay close attention to the changes in functions of organs, and strengthen the therapeutic strategies to support the function of organs to reduce the incidence of systemic complications. The control of the infection and the timely and effective repair of the wound are still the key points of the treatment of an extensive local radiation injury.

  5. MO-D-BRB-00: Pediatric Radiation Therapy Planning, Treatment, and Late Effects

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-06-15

    Most Medical Physicists working in radiotherapy departments see few pediatric patients. This is because, fortunately, children get cancer at a rate nearly 100 times lower than adults. Children have not smoked, abused alcohol, or been exposed to environmental carcinogens for decades, and of course, have not fallen victim to the aging process. Children get very different cancers than adults. Breast or prostate cancers, typical in adults, are rarely seen in children but instead a variety of tumors occur in children that are rarely seen in adults; examples are germinomas, ependymomas and primitive neuroectodermal tumors, which require treatment of the child’s brain or neuroblastoma, requiring treatment in the abdomen. The treatment of children with cancer using radiation therapy is one of the most challenging planning and delivery problems facing the physicist. This is because bones, brain, breast tissue, and other organs are more sensitive to radiation in children than in adults. Because most therapy departments treat mostly adults, when the rare 8 year-old patient comes to the department for treatment, the physicist may not understand the clinical issues of his disease which drive the planning and delivery decisions. Additionally, children are more prone than adults to developing secondary cancers after radiation. For bilateral retinoblastoma for example, an irradiated child has a 40% chance of developing a second cancer by age 50. The dosimetric tradeoffs made during the planning process are complex and require careful consideration for children treated with radiotherapy. In the first presentation, an overview of childhood cancers and their corresponding treatment techniques will be given. These can be some of the most complex treatments that are delivered in the radiation therapy department. These cancers include leukemia treated with total body irradiation, medulloblastoma, treated with craniospinal irradiation plus a conformal boost to the posterior fossa

  6. Treatment of retinoblastoma by precision megavoltage radiation therapy

    Energy Technology Data Exchange (ETDEWEB)

    Schipper, J.; Peperzeel, H.A. van (Rijksuniversiteit Utrecht (Netherlands). Academisch Ziekenhuis); Tan, K.E.W.P. (Royal Dutch Eye Hospital, Utrecht, Netherlands)

    1985-02-01

    The principal treatment concept in the Utrecht Retinoblastoma Centre is megavoltage irradiation, followed by light coagulation and/or cryotherapy if there is any doubt as to whether the residual tumour is still active. Radiation therapy is administered by means of a simple but highly accurate temporal beam technique. A standardized dose of 45 Gy is given in 15 fractions of 3 Gy at 3 fractions per week. From 1971 to 1982, 39 children with retinoblastoma have been irradiated in at least one eye. Of the 73 affected eyes, 18 were primarily enucleated, one received light coagulation only, and 54 received radiation therapy. Of the 54 irradiated eyes, 32 were additionally treated by light coagulation and/or cryotherapy for suspicious residual tumour (in 29 eyes), recurrent tumour (in 1 eye), and/or new tumour (in 3 eyes) and 10 were ultimately enucleated. Two eyes also received hyperthermia. The percentages of cure of the irradiated eyes with a minimum follow-up of 2 years were 100% (14/14), 100% (9/9), 83% (10/12), 79% (11/14) and 0% (0/5) in the Reese-Ellsworth groups I to V-A, respectively. Of the saved eyes 95% achieved useful vision. Eighteen eyes developed a clinically detectable radiation cataract; in five of these the lens was aspirated. Cataracts developed exclusively in those lenses of which a posterior portion of more than 1 mm had to be included in the treatment field. The likelihood and the degree of cataract formation was found to be directly related to the dose of radiation to the germinative zone of the lens epithelium. The minimum cataractogenic dose found in this series was 8 Gy.

  7. Acute Toxicity After Image-Guided Intensity Modulated Radiation Therapy Compared to 3D Conformal Radiation Therapy in Prostate Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Wortel, Ruud C.; Incrocci, Luca [Department of Radiation Oncology, Erasmus Medical Center Cancer Institute, Rotterdam (Netherlands); Pos, Floris J.; Lebesque, Joos V.; Witte, Marnix G.; Heide, Uulke A. van der; Herk, Marcel van [Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands); Heemsbergen, Wilma D., E-mail: w.heemsbergen@nki.nl [Department of Radiation Oncology, Netherlands Cancer Institute, Amsterdam (Netherlands)

    2015-03-15

    Purpose: Image-guided intensity modulated radiation therapy (IG-IMRT) allows significant dose reductions to organs at risk in prostate cancer patients. However, clinical data identifying the benefits of IG-IMRT in daily practice are scarce. The purpose of this study was to compare dose distributions to organs at risk and acute gastrointestinal (GI) and genitourinary (GU) toxicity levels of patients treated to 78 Gy with either IG-IMRT or 3D-CRT. Methods and Materials: Patients treated with 3D-CRT (n=215) and IG-IMRT (n=260) receiving 78 Gy in 39 fractions within 2 randomized trials were selected. Dose surface histograms of anorectum, anal canal, and bladder were calculated. Identical toxicity questionnaires were distributed at baseline, prior to fraction 20 and 30 and at 90 days after treatment. Radiation Therapy Oncology Group (RTOG) grade ≥1, ≥2, and ≥3 endpoints were derived directly from questionnaires. Univariate and multivariate binary logistic regression analyses were applied. Results: The median volumes receiving 5 to 75 Gy were significantly lower (all P<.001) with IG-IMRT for anorectum, anal canal, and bladder. The mean dose to the anorectum was 34.4 Gy versus 47.3 Gy (P<.001), 23.6 Gy versus 44.6 Gy for the anal canal (P<.001), and 33.1 Gy versus 43.2 Gy for the bladder (P<.001). Significantly lower grade ≥2 toxicity was observed for proctitis, stool frequency ≥6/day, and urinary frequency ≥12/day. IG-IMRT resulted in significantly lower overall RTOG grade ≥2 GI toxicity (29% vs 49%, respectively, P=.002) and overall GU grade ≥2 toxicity (38% vs 48%, respectively, P=.009). Conclusions: A clinically meaningful reduction in dose to organs at risk and acute toxicity levels was observed in IG-IMRT patients, as a result of improved technique and tighter margins. Therefore reduced late toxicity levels can be expected as well; additional research is needed to quantify such reductions.

  8. Effect of treatment modality on the hypothalamic-pituitary function of patients treated with radiation therapy for pituitary adenomas: Hypothalamic dose and endocrine outcomes.

    OpenAIRE

    Andrew eElson; Joseph eBovi; Kawaljeet eKaur; Diana eMaas; Grant eSinson; Chris eSchultz

    2014-01-01

    Background: Both fractionated external beam radiotherapy and single fraction radiosurgery for pituitary adenomas are associated with the risk of hypothalamic-pituitary (HP) axis dysfunction.Objective: To analyze the effect of treatment modality (Linac, TomoTherapy, or Gamma Knife) on hypothalamic dose and correlate these with HP-Axis deficits after radiotherapy.Methods:Radiation plans of patients treated postoperatively for pituitary adenomas using Linac-based 3D Conformal Radiotherapy (CRT) ...

  9. Effect of Treatment Modality on the Hypothalamic–Pituitary Function of Patients Treated with Radiation Therapy for Pituitary Adenomas: Hypothalamic Dose and Endocrine Outcomes

    OpenAIRE

    Elson, Andrew; Bovi, Joseph; Kaur, Kawaljeet; Maas, Diana; Sinson, Grant; Schultz, Chris

    2014-01-01

    Background: Both fractionated external beam radiotherapy and single fraction radiosurgery for pituitary adenomas are associated with the risk of hypothalamic–pituitary (HP) axis dysfunction. Objective: To analyze the effect of treatment modality (Linac, TomoTherapy, or gamma knife) on hypothalamic dose and correlate these with HP-axis deficits after radiotherapy. Methods: Radiation plans of patients treated post-operatively for pituitary adenomas using Linac-based 3D-conformal radiother...

  10. Three-Year Outcomes of a Canadian Multicenter Study of Accelerated Partial Breast Irradiation Using Conformal Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Berrang, Tanya S., E-mail: tberrang@bccancer.bc.ca [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Olivotto, Ivo [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Kim, Do-Hoon [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada); Nichol, Alan [British Columbia Cancer Agency-Vancouver Centre, BC (Canada); University of British Columbia, BC (Canada); Cho, B.C. John [Princess Margaret Hospital, Ontario (Canada); University of Toronto, Ontario (Canada); Mohamed, Islam G. [British Columbia Cancer Agency-Southern Interior, BC (Canada); University of British Columbia, BC (Canada); Parhar, Tarnjit [British Columbia Cancer Agency-Vancouver Centre, BC (Canada); University of British Columbia, BC (Canada); Wright, J.R. [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada); Truong, Pauline [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Tyldesley, Scott [British Columbia Cancer Agency-Vancouver Centre, BC (Canada); University of British Columbia, BC (Canada); Sussman, Jonathan [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada); Wai, Elaine [British Columbia Cancer Agency-Vancouver Island, BC (Canada); University of British Columbia, BC (Canada); Whelan, Tim [Juravinski Cancer Centre, Ontario (Canada); McMaster University, Ontario (Canada)

    2011-12-01

    Purpose: To report 3-year toxicity, cosmesis, and efficacy of a multicenter study of external beam, accelerated partial breast irradiation (APBI) for early-stage breast cancer. Methods and Materials: Between March 2005 and August 2006, 127 women aged {>=}40 years with ductal carcinoma in situ or node-negative invasive breast cancer {<=}3 cm in diameter, treated with breast-conserving surgery achieving negative margins, were accrued to a prospective study involving five Canadian cancer centers. Women meeting predefined dose constraints were treated with APBI using 3 to 5 photon beams, delivering 35 to 38.5 Gy in 10 fractions, twice a day, over 1 week. Patients were assessed for treatment-related toxicities, cosmesis, and efficacy before APBI and at specified time points for as long as 3 years after APBI. Results: 104 women had planning computed tomography scans showing visible seromas, met dosimetric constraints, and were treated with APBI to doses of 35 Gy (n = 9), 36 Gy (n = 33), or 38.5 Gy (n = 62). Eighty-seven patients were evaluated with minimum 3-year follow-up after APBI. Radiation dermatitis, breast edema, breast induration, and fatigue decreased from baseline levels or stabilized by the 3-year follow-up. Hypopigmentation, hyperpigmentation, breast pain, and telangiectasia slightly increased from baseline levels. Most toxicities at 3 years were Grade 1. Only 1 patient had a Grade 3 toxicity with telangiectasia in a skin fold inside the 95% isodose. Cosmesis was good to excellent in 86% (89/104) of women at baseline and 82% (70/85) at 3 years. The 3-year disease-free survival was 97%, with only one local recurrence that occurred in a different quadrant away from the treated site and two distant recurrences. Conclusions: At 3 years, toxicity and cosmesis were acceptable, and local control and disease-free survival were excellent, supporting continued accrual to randomized APBI trials.

  11. Prevention of normal tissue complications in radiation therapy of head and neck cancer : the role of 3D conformal radiation therapy (3DCRT)

    NARCIS (Netherlands)

    O.B. Wijers (Oda)

    2002-01-01

    textabstractIn The Netherlands. head and neck cancer (3.9%) ranks the eighth most frequemly diagnoscd malignant tumor. Radiation therapy (IIT) plays an important role in the treatmem of patients with head and neck cancer, as they constitute approximately 6% of those treated in a routine radiation th

  12. Definitive conformation radiotherapy combined with chemo-hormonal therapy in the treatment of adenocarcinoma of the prostate

    Energy Technology Data Exchange (ETDEWEB)

    Karasawa, Katsuyuki; Kodaira, Takeshi [Tokyo Metropolitan Komagome Hospital (Japan); Nakagawa, Keiichi; Onogi, Yuzo; Hara, Hiroshi; Matsumoto, Hidetsugu; Sasaki, Yasuhito

    1996-12-01

    To ascertain the clinical benefits of photon conformation radiotherapy, since 1988 we have been conducting a clinical trial of photon conformation radiotherapy for adenocarcinoma of the prostate, and we have analyzed the findings thus far. Between 1988 and 1993, 33 evaluable patients with prostate cancer were treated with definitive radiotherapy at the Dept. of Radiology, Social Health Insurance Medical Center. Their ages ranged from 54 to 86, and averaged 69.3 y.o. (median 67). Their stages were as follows: 3 stage-B, 25 stage-C, and 5 stage-D cases. The minimum follow-up period was 1 year. Patients received 40 to 50 Gy (fraction dose ranged from 1.8 Gy to 2 Gy) to the pelvis using the AP-PA technique followed by a 20 to 30 Gy conformal boost (fraction dose 2 Gy) to the prostate gland. Total dose ranged from 68 Gy to 70.4 Gy, with an average of 70 Gy. Systemic multiagent chemotherapy with CDDP, ADR, MTX, 5FU, and CPM was administered concurrently and adjuvantly. Hormonal therapy was also adjuvantly administered. Overall survival rates at 3 years for stage B, C, and D were 100%, 100%, and 60%, respectively. and was 85% at 5 years for stage C. Relapse-free survival rates at 3 years for stage B and C were 100% and 96%, respectively, and was 61% at 5 years for stage C. Regarding stage C cases, the initial site of recurrence was bone in 5 cases. As for complications, there were 5 (15%) grade 1, 4 (12%) grade 2, and 1 (3%) grade 3 rectal complications. Although the number of cases is rather small and the follow-up period is rather short, definitive conformal radiotherapy with adjuvant chemo-hormonal therapy appears promising in the treatment of prostate cancer by improving survival rates with acceptable normal tissue toxicity. (author)

  13. Does IMRT increase the peripheral radiation dose? A comparison of treatment plans 2000 and 2010

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    Salz, Henning; Eichner, Regina; Wiezorek, Tilo [Jena Univ. (Germany). Dept. of Radiation Oncology

    2012-07-01

    It has been reported in several papers and textbooks that IMRT treatments increase the peripheral dose in comparison with non-IMRT fields. But in clinical practice not only open fields have been used in the pre-IMRT era, but also fields with physical wedges or composed fields. The aim of this work is to test the hypothesis of increased peripheral dose when IMRT is used compared to standard conformal radiotherapy. Furthermore, the importance of the measured dose differences in clinical practice is discussed and compared with other new technologies for the cases where an increase of the peripheral dose was observed. For cancers of the head and neck, the cervix, the rectum and for the brain irradiation due to acute leukaemia, one to four plans have been calculated with IMRT or conformal standard technique (non-IMRT). In an anthropomorphic phantom the dose at a distance of 30 cm in cranio-caudal direction from the target edge was measured with TLDs using a linear accelerator Oncor {sup registered} (Siemens) for both techniques. IMRT was performed using step-and-shoot technique (7 to 11 beams), non-IMRT plans with different techniques. The results depended on the site of irradiation. For head and neck cancers IMRT resulted in an increase of 0.05 - 0.09% of the prescribed total dose (Dptv) or 40 - 70 mGy (Dptv = 65 Gy), compared to non-IMRT technique without wedges or a decrease of 0.16% (approx. 100 mGy) of the prescribed total dose compared to non-IMRT techniques with wedges. For the cervical cancer IMRT resulted in an increased dose in the periphery (+ 0.07% - 0.15% of Dptv or 30 - 70 mGy at Dptv = 45 Gy), for the rectal cancer in a dose reduction (0.21 - 0.26% of Dptv or 100 - 130 mGy at Dptv = 50 Gy) and for the brain irradiation in an increase dose (+ 0.05% of Dptv = 18 Gy or 9 mSv). In summary IMRT does not uniformly cause increased radiation dose in the periphery in the model used. It can be stated that these dose values are smaller than reported in earlier

  14. Gamma radiation induced effects on slaughterhouse wastewater treatment

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    Melo, Rita [Departamento de Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal)], E-mail: ritamelo@itn.pt; Cabo Verde, Sandra [Departamento de Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal); Branco, Joaquim [Departamento de Quimica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal); Botelho, M. Luisa [Departamento de Fisica, Instituto Tecnologico e Nuclear, Estrada Nacional 10, Apartado 21, 2686-953 Sacavem (Portugal)

    2008-01-15

    A preliminary study using gamma radiation on slaughterhouse wastewater samples was carried out. Chemical oxygen demand (COD), biochemical oxygen demand (BOD) and total suspended solids (TSS) results were obtained at a dose rate of 0.9 kGy h{sup -1}. A decrease of COD, BOD and colour was observed after irradiation at high absorbed doses. The microbiological results, following irradiation in the same conditions, correlated with the BOD results. The results obtained highlight the potential of this technology for wastewater treatment.

  15. An investigation of intensity-modulated radiation therapy versus conventional two-dimensional and 3D-conformal radiation therapy for early stage larynx cancer

    Directory of Open Access Journals (Sweden)

    Gomez Daniel

    2010-08-01

    Full Text Available Abstract Introduction Intensity modulated radiation therapy (IMRT has been incorporated at several institutions for early stage laryngeal cancer (T1/T2N0M0, but its utility is controversial. Methods In three representative patients, multiple plans were generated: 1 Conventional 2D planning, with the posterior border placed at either the anterior aspect ("tight" plan or the mid-vertebral body ("loose" plan, 2 3D planning, utilizing both 1.0 and 0.5 cm margins for the planning target volume (PTV, and 3 IMRT planning, utilizing the same margins as the 3D plans. A dosimetric comparison was performed for the target volume, spinal cord, arytenoids, and carotid arteries. The prescription dose was 6300 cGy (225 cGy fractions, and the 3D and IMRT plans were normalized to this dose. Results For PTV margins of 1.0 cm and 0.5 cm, the D95 of the 2D tight/loose plans were 3781/5437 cGy and 5372/5869 cGy, respectively (IMRT/3D plans both 6300 cGy. With a PTV margin of 1.0 cm, the mean carotid artery dose was 2483/5671/5777/4049 cGy in the 2D tight, 2D loose, 3D, and IMRT plans, respectively. When the PTV was reduced to 0.5 cm, the the mean carotid artery dose was 2483/5671/6466/2577 cGy to the above four plans, respectively. The arytenoid doses were similar between the four plans, and spinal cord doses were well below tolerance. Conclusions IMRT provides a more ideal dose distribution compared to 2D treatment and 3D planning in regards to mean carotid dose. We therefore recommend IMRT in select cases when the treating physician is confident with the GTV.

  16. Treatment optimisation using external beam radiation in gynaecological cancers

    Directory of Open Access Journals (Sweden)

    V. Sharma

    2004-03-01

    Full Text Available The majority of patients with gynaecological cancers present with advanced stages in which external beam radiation forms a major component of the treatment. These patients undergo simulation for treatment planning prior to radiation. Currently the lower extent of the disease is evaluated by vaginal examination and marked using a lead wire on the anterior abdominal wall in the pelvic region. A 2 cm margin inferior to this level is used as the lower border of the treatment field. The suggested modified technique includes the placement of an indigenously designed perspex vaginal obturator with graduations at 1 cm distance from its tip. Following vaginal examination the obturator can be inserted into the vagina and fixed at the predefined length using a fixation device. The radio-opaque markers can be seen even in the lateral films. Twentyfive consecutive patients underwent the procedure and the differences between the two methods of marking the lower border were calculated. The external lead wire was inferior to the internal obturator in 19 patients (76% ranging from 0.5 cm to 3 cm (median 1.5 cm, mean 1.37 cm. It was at the same level in 4 patients (16% and 1 cm superior to the internal obturator in 2 (8%. With the modified technique using the internal obturator application for delineating the lower border of vaginal disease or vault, it was possible to decrease the length of field thereby reducing the chances of treatment-related toxicity, especially groin and vulval reactions, as well as avoiding treatment interruptions.

  17. Detection of radiation treatment of beans using DNA comet assay

    Science.gov (United States)

    Khan, Ashfaq A.; Khan, Hasan M.; Delincée, Henry

    2002-03-01

    A simple technique of microgel electrophoresis of single cells (DNA Comet Assay) enabled a quick detection of radiation treatment of several kinds of leguminous beans (azuki, black, black eye, mung, pinto, red kidney and white beans). Each variety was exposed to radiation doses of 0.5, 1 and 5kGy covering the permissible limits for insect disinfestation. The cells or nuclei from beans were extracted in cold PBS, embedded in agarose on microscope slides, lysed between 15 and 60min in 2.5% SDS and electrophoresis was carried out at a voltage of 2V/cm for 2-2.5min. After silver staining, the slides were evaluated through an ordinary transmission microscope. In irradiated samples, fragmented DNA stretched towards the anode and the damaged cells appeared as a comet. The density of DNA in the tails increased with increasing radiation dose. However, in non-irradiated samples, the large molecules of DNA remained relatively intact and there was only minor or no migration of DNA; the cells were round or had very short tails only. Hence, the DNA comet assay provides an inexpensive, rapid and relatively simple screening method for the detection of irradiated beans.

  18. Photodegradation of etridiazole by UV radiation during drinking water treatment.

    Science.gov (United States)

    Liu, Chao; Qiang, Zhimin; Tian, Fang; Zhang, Tao

    2009-07-01

    The photodegradation of etridiazole (ETZ) in water by UV radiation at 254 nm was investigated. Results indicate that the simulated first-order rate constants decreased with the increase of initial ETZ concentration (i.e., 5, 20 and 30 microM), and did not show any pH dependence within the range from 6.0 to 8.0. The quantum yield was 0.46+/-0.02 molE(-1) at pH 7.0. H(2)O(2) was generated at trace levels in the range from 0 to 1.0 microM during photodegradation of ETZ. Direct photodegradation was responsible for the decomposition of ETZ in distilled water by UV radiation. Three organic byproducts were identified: 5-ethoxy-3-dichloromethyl-1,2,4-thiadiazole, 5-ethoxy-1,2,4-thiadiazole-3-carboxylic acid and 5-ethoxy-3-hydroxyl-1,2,4-thiadiazole. About 90% of chloro mass in the initial ETZ was released as Cl(-) at the end of photodegradation. In contrast, the formation of sulfate and nitrate was insignificant. In general, ETZ decayed more quickly in groundwater than in sand-filtered or surface water. It is reasonably deduced that ETZ may not get removed effectively under a typical UV dose of 40 mJcm(-2) at most water treatment plants that employ UV radiation for disinfection.

  19. Dianhydrogalactitol and radiation therapy. Treatment of supratentorial glioma.

    Science.gov (United States)

    Eagan, R T; Childs, D S; Layton, D D; Laws, E R; Bisel, H F; Holbrook, M A; Fleming, T R

    1979-05-11

    Dianhydrogalactitol was the most active of 177 agents tested against a mouse ependymoblastoma tumor. We conducted a prospectively randomized trial comparing whole-brain irradiation alone vs identical irradiation plus dianhydrogalactitol in 42 patients with grade 3 and 4 supratentorial astrocytomas. Patients receiving dianhydrogalactitol in addition to irradiation had a significantly longer median survival time (67 vs 35 weeks) than did patients receiving only irradiation. The major toxic effect of dianhydrogalactitol is hematologic suppression of a cumulative nature. Dianhydrogalactitol may play an important role (in conjunction with radiation therapy) in the initial treatment of patients with supratentorial glioma. Our data may indicate that the mouse ependymoblastoma system is a useful screen for agents to be used in the treatment of human glioma.

  20. Decision tools for radiation oncology. Prognosis, treatment response and toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Nieder, Carsten [Tromso Univ., Bodo (Norway). Dept. of Oncology; Gaspar, Laurie E. (ed.) [Colorado Univ., Aurora, CO (United States). Dept. of Radiation Oncology

    2014-04-01

    Comprehensive overview of prognostic and predictive models for radiation oncology, stratified by disease site. Identification of models' limits and caveats. Excellent aid to decision making in daily clinical practice. A look at the recent oncology literature or a search of one of the common databases reveals a steadily increasing number of nomograms and other prognostic models, some of which are also available in the form of web-based tools. These models may predict the risk of relapse, lymphatic spread of a given malignancy, toxicity, survival, etc. Pathology information, gene signatures, and clinical data may all be used to compute the models. This trend reflects increasingly individualized treatment concepts and also the need for approaches that achieve a favorable balance between effectiveness and side-effects. Moreover, optimal resource utilization requires prognostic knowledge, for example to avoid lengthy and aggressive treatment courses in patients with a short survival expectation. In order to avoid misuse, it is important to understand the limits and caveats of prognostic and predictive models. This book provides a comprehensive overview of such decision tools for radiation oncology, stratified by disease site, which will enable readers to make informed choices in daily clinical practice and to critically follow the future development of new tools in the field.

  1. Influence of different treatment techniques on radiation dose to the LAD coronary artery

    Directory of Open Access Journals (Sweden)

    Molls Michael

    2007-06-01

    Full Text Available Abstract Background The purpose of this proof-of-principle study was to test the ability of an intensity-modulated radiotherapy (IMRT technique to reduce the radiation dose to the heart plus the left ventricle and a coronary artery. Radiation-induced heart disease might be a serious complication in long-term cancer survivors. Methods Planning CT scans from 6 female patients were available. They were part of a previous study of mediastinal IMRT for target volumes used in lymphoma treatment that included 8 patients and represent all cases where the left anterior descending coronary artery (LAD could be contoured. We compared 6 MV AP/PA opposed fields to a 3D conformal 4-field technique and an optimised 7-field step-and-shoot IMRT technique and evaluated DVH's for several structures. The planning system was BrainSCAN 5.21 (BrainLAB, Heimstetten, Germany. Results IMRT maintained target volume coverage but resulted in better dose reduction to the heart, left ventricle and LAD than the other techniques. Selective dose reduction could be accomplished, although not to the degree initially attempted. The median LAD dose was approximately 50% lower with IMRT. In 5 out of 6 patients, IMRT was the best technique with regard to heart sparing. Conclusion IMRT techniques are able to reduce the radiation dose to the heart. In addition to dose reduction to whole heart, individualised dose distributions can be created, which spare, e.g., one ventricle plus one of the coronary arteries. Certain patients with well-defined vessel pathology might profit from an approach of general heart sparing with further selective dose reduction, accounting for the individual aspects of pre-existing damage.

  2. Distribution of the h-index in radiation oncology conforms to a variation of power law: implications for assessing academic productivity.

    Science.gov (United States)

    Quigley, Matthew R; Holliday, Emma B; Fuller, Clifton D; Choi, Mehee; Thomas, Charles R

    2012-06-01

    Leaders of academic institutions evaluate academic productivity when deciding to hire, promote, or award resources. This study examined the distribution of the h-index, an assessment of academic standing, among radiation oncologists. The authors collected h-indices for 826 US academic radiation oncologists from a commercial bibliographic database (SCOPUS, Elsevier B.V., NL). Then, logarithmic transformation was performed on h-indices and ranked h-indices, and results were compared to estimates of a power law distribution. The h-index frequency distribution conformed to both the log-linear variation of a power law (r (2) = .99) and the beta distribution with the same fitting exponents as previously described in a power law analysis of the productivity of neurosurgeons. Within radiation oncology, as in neurosurgery, there are exceedingly more faculty with an h-index of 1-2. The distribution fitting the same variation of a power law within two fields suggests applicability to other areas of academia.

  3. Current state of methodological and decisions for radiation treatment of blood, its components and products

    Directory of Open Access Journals (Sweden)

    Gordeev A.V.

    2014-12-01

    Full Text Available This article presents currently used blood transfusion media — components and blood products, therapeutic effects, reactions and complications of blood transfusion, use of radiation treatment for blood transfusion fluids. There had been discussed in detail the practice of radiation processing of blood components and for the prevention of reaction "graft versus host" and studies of plasma radiation treatment for its infectious safety. There was presented the current state of techniques and technical solutions of radiation treatment of transfusion-transmissible environments. There were also considered an alternative to radiation treatment of blood.

  4. Analysis of the absorbed dose in skin for head and neck intensity modulated radiation therapy treatments; Analisis de la dosis absorbida en piel en tratamientos de radioterapia de intensidad modulada en cabeza y cuello

    Energy Technology Data Exchange (ETDEWEB)

    Llorente Manso, M.; Vicente Toribio, T.

    2009-07-01

    Intensity Modulated Radiation Therapy is becoming a common technique for treatment of head and neck tumours. The use of inverse planning techniques can lead to an unwanted skin dose and toxicity increase. In this study we present a quantitative evaluation of such phenomenon and propose an optimization method for skin dose reduction to the level usual in conventional Conformal Radiotherapy. (Author) 10 refs.

  5. Radiation therapy of intracranial germinomas: optimum radiation dose and treatment volume

    Energy Technology Data Exchange (ETDEWEB)

    Chang, Sei Kyung [Eulji Medical College, Taejon (Korea, Republic of); Suh, Chang Ok; Kim, Gwi Eon [College of Medicine, Yonsei Univ., Seoul (Korea, Republic of)

    1999-09-01

    To evaluate the possibility of decreasing the radiation dose and to determine optimum treatment volume in intracranial germinomas. Forty five patients with pathologically-verified or presumed germinomas by a radiosensitivity test who had been treated with radiotherapy (RT) alone between 1971 and 1992 were retrospectively analyzed. The average age was 17.2 years with 68.9% of the patients being between the ages of 10-20. The male and female ratio was 2.2:1. The locations of the primary tumors were at the pineal regions in 14 patients; the suprasellar regions in 12 patients; and multiple sites in 12 patients. Treatment volumes varied from a small local field (1Q) to the whole brain (7) or entire neuroaxis irradiation(28). All the cases after 1982 received craniospinal irradiation (CSI). Radiation .doses were 41-59 Gv (median 48.5 Gy) to the primary tumor site and 19.5-36 Gy (median 24 Gy) to the neuroaxis. The median follow-up period was 82 months with a range of 2-260 months. All the patients showed complete response after AT. Four patients suffered from recurrence 14. 65. 76, and 170 months after AT,. respectively, and two patients died with intercurrent disease. One of four recurrent cases was salvaged by re-irradiation. Therefore, a 5 and 10 year overall survival was 95.3 % and 84.7 % respectively. Five and ten year disease free survival was 97.6 % and 88.8 % respectively. All the recurrences occurred in the patients who received local RT (3/10) or whole brain RT (1/7) with a radiation dose of 48-50 Gy. None of the patients who received CSJ suffered recurrence. There was no recurrence among the 15 patients who received 45 Gy to the primary site and the 18 patients who received 24 Gy (6 patients received 19.5 Gy) to the neuroaxis. CSI is recommended for the treatment of intracranial germinomas. The radiation dose can be safely decreased to {<=}45 Gy on a primary tumor site and 19.5 Gy on the spine.

  6. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-03-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  7. Conformal Nets II: Conformal Blocks

    Science.gov (United States)

    Bartels, Arthur; Douglas, Christopher L.; Henriques, André

    2017-08-01

    Conformal nets provide a mathematical formalism for conformal field theory. Associated to a conformal net with finite index, we give a construction of the `bundle of conformal blocks', a representation of the mapping class groupoid of closed topological surfaces into the category of finite-dimensional projective Hilbert spaces. We also construct infinite-dimensional spaces of conformal blocks for topological surfaces with smooth boundary. We prove that the conformal blocks satisfy a factorization formula for gluing surfaces along circles, and an analogous formula for gluing surfaces along intervals. We use this interval factorization property to give a new proof of the modularity of the category of representations of a conformal net.

  8. MINERVA - a multi-modal radiation treatment planning system

    Energy Technology Data Exchange (ETDEWEB)

    Wemple, C.A. E-mail: cew@enel.gov; Wessol, D.E.; Nigg, D.W.; Cogliati, J.J.; Milvich, M.L.; Frederickson, C.; Perkins, M.; Harkin, G.J

    2004-11-01

    Researchers at the Idaho National Engineering and Environmental Laboratory and Montana State University have undertaken development of MINERVA, a patient-centric, multi-modal, radiation treatment planning system. This system can be used for planning and analyzing several radiotherapy modalities, either singly or combined, using common modality independent image and geometry construction and dose reporting and guiding. It employs an integrated, lightweight plugin architecture to accommodate multi-modal treatment planning using standard interface components. The MINERVA design also facilitates the future integration of improved planning technologies. The code is being developed with the Java Virtual Machine for interoperability. A full computation path has been established for molecular targeted radiotherapy treatment planning, with the associated transport plugin developed by researchers at the Lawrence Livermore National Laboratory. Development of the neutron transport plugin module is proceeding rapidly, with completion expected later this year. Future development efforts will include development of deformable registration methods, improved segmentation methods for patient model definition, and three-dimensional visualization of the patient images, geometry, and dose data. Transport and source plugins will be created for additional treatment modalities, including brachytherapy, external beam proton radiotherapy, and the EGSnrc/BEAMnrc codes for external beam photon and electron radiotherapy.

  9. Computed tomography imaging parameters for inhomogeneity correction in radiation treatment planning

    Directory of Open Access Journals (Sweden)

    Indra J Das

    2016-01-01

    Full Text Available Modern treatment planning systems provide accurate dosimetry in heterogeneous media (such as a patient' body with the help of tissue characterization based on computed tomography (CT number. However, CT number depends on the type of scanner, tube voltage, field of view (FOV, reconstruction algorithm including artifact reduction and processing filters. The impact of these parameters on CT to electron density (ED conversion had been subject of investigation for treatment planning in various clinical situations. This is usually performed with a tissue characterization phantom with various density plugs acquired with different tube voltages (kilovoltage peak, FOV reconstruction and different scanners to generate CT number to ED tables. This article provides an overview of inhomogeneity correction in the context of CT scanning and a new evaluation tool, difference volume dose-volume histogram (DVH, dV-DVH. It has been concluded that scanner and CT parameters are important for tissue characterizations, but changes in ED are minimal and only pronounced for higher density materials. For lungs, changes in CT number are minimal among scanners and CT parameters. Dosimetric differences for lung and prostate cases are usually insignificant (<2% in three-dimensional conformal radiation therapy and < 5% for intensity-modulated radiation therapy (IMRT with CT parameters. It could be concluded that CT number variability is dependent on acquisition parameters, but its dosimetric impact is pronounced only in high-density media and possibly in IMRT. In view of such small dosimetric changes in low-density medium, the acquisition of additional CT data for financially difficult clinics and countries may not be warranted.

  10. Comparison of different breast planning techniques and algorithms for radiation therapy treatment.

    Science.gov (United States)

    Borges, C; Cunha, G; Monteiro-Grillo, I; Vaz, P; Teixeira, N

    2014-03-01

    This work aims at investigating the impact of treating breast cancer using different radiation therapy (RT) techniques--forwardly-planned intensity-modulated, f-IMRT, inversely-planned IMRT and dynamic conformal arc (DCART) RT--and their effects on the whole-breast irradiation and in the undesirable irradiation of the surrounding healthy tissues. Two algorithms of iPlan BrainLAB treatment planning system were compared: Pencil Beam Convolution (PBC) and commercial Monte Carlo (iMC). Seven left-sided breast patients submitted to breast-conserving surgery were enrolled in the study. For each patient, four RT techniques--f-IMRT, IMRT using 2-fields and 5-fields (IMRT2 and IMRT5, respectively) and DCART - were applied. The dose distributions in the planned target volume (PTV) and the dose to the organs at risk (OAR) were compared analyzing dose-volume histograms; further statistical analysis was performed using IBM SPSS v20 software. For PBC, all techniques provided adequate coverage of the PTV. However, statistically significant dose differences were observed between the techniques, in the PTV, OAR and also in the pattern of dose distribution spreading into normal tissues. IMRT5 and DCART spread low doses into greater volumes of normal tissue, right breast, right lung and heart than tangential techniques. However, IMRT5 plans improved distributions for the PTV, exhibiting better conformity and homogeneity in target and reduced high dose percentages in ipsilateral OAR. DCART did not present advantages over any of the techniques investigated. Differences were also found comparing the calculation algorithms: PBC estimated higher doses for the PTV, ipsilateral lung and heart than the iMC algorithm predicted.

  11. Three-dimensional conformal radiation for esophageal squamous cell carcinoma with involved-field irradiation may deliver considerable doses of incidental nodal irradiation

    Directory of Open Access Journals (Sweden)

    Ji Kai

    2012-11-01

    Full Text Available Abstract Background To quantify the incidental irradiation dose to esophageal lymph node stations when irradiating T1-4N0M0 thoracic esophageal squamous cell carcinoma (ESCC patients with a dose of 60 Gy/30f. Methods Thirty-nine patients with medically inoperable T1–4N0M0 thoracic ESCC were treated with three-dimensional conformal radiation (3DCRT with involved-field radiation (IFI. The conformal clinical target volume (CTV was re-created using a 3-cm margin in the proximal and distal direction beyond the barium esophagogram, endoscopic examination and CT scan defined the gross tumor volume (GTV and a 0.5-cm margin in the lateral and anteroposterior directions of the CT scan-defined GTV. The PTV encompassed 1-cm proximal and distal margins and 0.5-cm radial margin based on the CTV. Nodal regions were delineated using the Japanese Society for Esophageal Diseases (JSED guidelines and an EORTC-ROG expert opinion. The equivalent uniform dose (EUD and other dosimetric parameters were calculated for each nodal station. Nodal regions with a metastasis rate greater than 5% were considered a high-risk lymph node subgroup. Results Under a 60 Gy dosage, the median Dmean and EUD was greater than 40 Gy in most high-risk nodal regions except for regions of 104, 106tb-R in upper-thoracic ESCC and 101, 104-R, 105, 106rec-L, 2, 3&7 in middle-thoracic ESCC and 107, 3&7 in lower-thoracic ESCC. In the regions with an EUD less than 40Gy, most incidental irradiation doses were significantly associated with esophageal tumor length and location. Conclusions Lymph node stations near ESCC receive considerable incidental irradiation doses with involved-field irradiation that may contribute to the elimination of subclinical lesions.

  12. Predictors of High-grade Esophagitis After Definitive Three-dimensional Conformal Therapy, Intensity-modulated Radiation Therapy, or Proton Beam Therapy for Non-small cell Lung Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Gomez, Daniel R., E-mail: dgomez@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Tucker, Susan L. [Department of Bioinformatics and Computational Biology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Martel, Mary K.; Mohan, Radhe; Balter, Peter A. [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Lopez Guerra, Jose Luis [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Hospitales Universitarios Virgen del Rocio, Seville (Spain); Liu Hongmei; Komaki, Ritsuko; Cox, James D.; Liao Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-11-15

    Introduction: We analyzed the ability of various patient- and treatment-related factors to predict radiation-induced esophagitis (RE) in patients with non-small cell lung cancer (NSCLC) treated with three-dimensional conformal radiation therapy (3D-CRT), intensity-modulated radiation therapy (IMRT), or proton beam therapy (PBT). Methods and Materials: Patients were treated for NSCLC with 3D-CRT, IMRT, or PBT at MD Anderson from 2000 to 2008 and had full dose-volume histogram (DVH) data available. The endpoint was severe (grade {>=}3) RE. The Lyman-Kutcher-Burman (LKB) model was used to analyze RE as a function of the fractional esophageal DVH, with clinical variables included as dose-modifying factors. Results: Overall, 652 patients were included: 405 patients were treated with 3D-CRT, 139 with IMRT, and 108 with PBT; corresponding rates of grade {>=}3 RE were 8%, 28%, and 6%, respectively, with a median time to onset of 42 days (range, 11-93 days). A fit of the fractional DVH LKB model demonstrated that the fractional effective dose was significantly different (P=.046) than 1 (fractional mean dose) indicating that high doses to small volumes are more predictive than mean esophageal dose. The model fit was better for 3D-CRT and PBT than for IMRT. Including receipt of concurrent chemotherapy as a dose-modifying factor significantly improved the LKB model (P=.005), and the model was further improved by including a variable representing treatment with >30 fractions. Examining individual types of chemotherapy agents revealed a trend toward receipt of concurrent taxanes and increased risk of RE (P=.105). Conclusions: Fractional dose (dose rate) and number of fractions (total dose) distinctly affect the risk of severe RE, estimated using the LKB model, and concurrent chemotherapy improves the model fit. This risk of severe RE is underestimated by this model in patients receiving IMRT.

  13. Volumetric-modulated arc therapy (VMAT versus 3D-conformal radiation therapy in supra-diaphragmatic Hodgkin’s Lymphoma with mediastinal involvement: A dosimetric comparison

    Directory of Open Access Journals (Sweden)

    Christine Higby

    2016-09-01

    Conclusions: VMAT is a valuable technique for treatment of large mediastinal HL. VMAT spares the lung and heart compared to 3DCRT using ISRT in select HL cases. VMAT allows dose escalation for post-chemotherapy residual disease with minimal dose to OARs. VMAT low radiation dose (V5 to the normal tissues, and the increased integral dose should be considered.

  14. Radiation treatment parameters for re-irradiation of malignant glioma

    Energy Technology Data Exchange (ETDEWEB)

    Niyazi, M.; Soehn, M.; Schwarz, S.B.; Lang, P.; Belka, C.; Ganswindt, U. [Ludwig-Maximilians-Univ., Muenchen (Germany). Dept. of Radiation Oncology

    2012-04-15

    Background and purpose: Most patients with malignant glioma ultimately fail locally or loco-regionally after the first treatment, with re-irradiation being a reasonable treatment option. However, only limited data are presently available allowing for a precise selection of patients suitable for re-treatment with regard to safety and efficacy. Material and methods: Using the department database, 39 patients with a second course of radiation were identified. Doses to gross tumor volume (GTV), planning target volume (PTV), and relevant organs at risk (OARs; brainstem, optic chiasm, optic nerves, brain) were retrospectively analyzed and correlated to outcome parameters. Relevant treatment parameters including D{sub max}, D{sub min}, D{sub mean}, and volume (ml) were obtained. Equivalent uniform dose (EUD) values were calculated for the tumor and OARs. To address the issue of radiation necrosis/leukoencephalopathy posttherapeutic MRI images were routinely examined every 3 months. Results: Median follow-up was 147 days. The time interval between first and second irradiation was regularly greater than 6 months. Median EUDs to the OARs were 11.9 Gy (range 0.7-27.4 Gy) to the optic chiasm, 17.6 Gy (range 0.7-43.0 Gy) to the brainstem, 4.9/2.1 Gy (range 0.3-24.5 Gy) to the right/left optic nerve, and 29.4 Gy (range 25.2-32.5 Gy) to the brain. No correlation between treated volume and survival was observed. Cold spots and dose did not correlate with survival. Re-irradiated volumes were treated with on average lower doses if they were larger and vice versa. Conclusion: In general, re-irradiation is a safe and feasible re-treatment option. No relevant toxicity was observed after re-irradiation in our patient cohort during follow-up. In this regard, this analysis provides baseline data for the selection of putative patients. EUD values are derived and may serve as reference for further studies, including intensity-modulated radiotherapy (IMRT) protocols. (orig.)

  15. Microbial community structure in different wastewater treatment processes characterized by single-strand conformation polymorphism (SSCP) technique

    Institute of Scientific and Technical Information of China (English)

    Yangguo ZHAO; Aijie WANG; Nanqi REN; Yan ZHAO

    2008-01-01

    In order to investigate microbial community structures in different wastewater treatment processes and understand the relationship between the structures and the status of processes, the microbial community diversity, variety and distribution in five wastewater treatment processes were studied by a culture-independent genetic fingerprinting technique single-strand conformation poly-morphism (SSCP). The five processes included denitrifying and phosphate-removal system (diminished N), Chinese traditional medicine wastewater treatment system (P), beer wastewater treatment system (W), fermentative biohydrogen-producing system (H), and sulfate-reduction system (S). The results indicated that the microbial community profiles in the wastewater bioreactors with the uniform status were very similar. The diversity of microbial populations was correlated with the complexity of organic contaminants in wastewater. Chinese traditional medicine wastewater contained more complex organic components; hence, the population diversity was higher than that of simple nutrient bioreactors fed with molasses wastewater. Compared with the strain bands in a simulated community, the relative proportion of some functional microbial populations in bioreactors was not dom-inant. Fermentative biohydrogen producer Ethanoligenens harbinense in the better condition bioreactor had only a 5% band density, and the Desulfovibrio sp. in the sulfate-reducing bioreactor had less than 1.5% band density. The SSCP profiles could identify the difference in microbial community structures in wastewater treatment processes, monitor some of the functional microbes in these processes, and consequently provide useful guidance for improving their efficiency.

  16. Intensity-modulated radiation therapy use for the localized treatment of thyroid cancer: Nationwide practice patterns and outcomes.

    Science.gov (United States)

    Goffredo, Paolo; Robinson, Timothy J; Youngwirth, Linda M; Roman, Sanziana A; Sosa, Julie A

    2016-09-01

    In the absence of randomized data, the optimal approach to adjuvant radiation therapy in locally advanced thyroid cancer remains unclear. We employed a large retrospective analysis to assess the best available evidence of a potential beneficial impact of intensity-modulated versus 3D-conformal radiotherapy (IMRT vs. 3D-CT). Retrospective analysis of adult thyroid cancer diagnosed between 2004 and 2011 within the National Cancer Database. Among patients treated with radiation therapy (N = 855), the use of IMRT (N = 437) increased among both comprehensive and academic centers (both p HR, 0.67; 95 % CI, 0.40-1.10; p = 0.115). This study presents the largest cohort to date examining receipt of IMRT in patients with locally advanced thyroid cancer and demonstrates an association between IMRT, treatment at a tertiary care center, higher total dose, and comparable or superior outcomes compared to patients treated with 3D conformal techniques despite more adverse disease features. In the absence of adequately powered prospective randomized trials, our retrospective analysis provides empirical evidence to support the use in these patients of dose escalation and IMRT, particularly at tertiary care centers.

  17. Immobilization for the radiation therapy treatment of the pelvic region

    Energy Technology Data Exchange (ETDEWEB)

    Van den Heuvel, F.; De Beukeleer, M.; Nys, F.; Bijdekerke, P.; Robberechts, M.; Van Cauwenbergh, R. [Brussels Univ. (Belgium). Dept. of Radiotherapy

    1995-12-01

    Previous experience with the treatment of the pelvic region has shown that geometric setup errors are considerable in extent and incidence. A proposal to alleviate this problem is the introduction of immobilization devices in analogy with head and neck treatment. The practicality and efficacy of such a technique is investigated and compared with an earlier proposed technique using interactive adjustment and Electronic Portal Imaging (EPI). A group of 13 patients treated in the pelvic region using external radiation therapy was immobilized using an Orfit-like cast. Every fraction for every patients was imaged using an EPID. Immediately after obtaining an image it was compared to a digitized simulation image using the in-house developed OPIDUM system. Patient position was adjusted when an error in one of the main directions (transversal or longitudinal) exceeded 5 mm. Time measurements were carried out in order to asses the impact of the immobilization procedure on the patient throughput. In 68% of the cases a corrective action was necessary. The fraction of total treatment time was 50% for 26% of the fields. The range of errors measured in the longitudinal direction was between 29 and -22 mm. In the transversal direction the range was from -7 to 60 mm. A full analysis 13 patients yielding statistics for more than 200 fields is presented. Special attention has been paid to the determination of the nature of the errors (random or systematic) and the impact on patient throughput.

  18. Chronic radiation proctopathy:A practical review of endoscopic treatment

    Institute of Scientific and Technical Information of China (English)

    Luciano Lenz; Rachel Rohr; Frank Nakao; Ermelindo Libera; Angelo Ferrari

    2016-01-01

    Chronic radiation proctopathy(CRP) is a troublesome complication of pelvic radiotherapy. The most common presentation is rectal bleeding. CRP symptoms interfere with daily activities and decrease quality of life. Rectal bleeding management in patients with CRP represents a conundrum for practitioners. Medical therapy is ineffective in general and surgical approach has a high morbidmortality. Endoscopy has a role in the diagnosis,staging and treatment of this disease. Currently available endoscopic modalities are formalin,potassium titanyl phosphate laser,neodymium:yttrium-aluminum-garnet laser,argon laser,bipolar electrocoagulation(BiCAP),heater probe,band ligation,cryotherapy,radiofrequency ablation and argon plasma coagulation(APC). Among these options,APC is the most promising.

  19. BNCT-RTPE: BNCT radiation treatment planning environment

    Energy Technology Data Exchange (ETDEWEB)

    Wessol, D.E.; Wheeler, F.J. [Idaho National Engineering Lab., Idaho Fall, ID (United States); Babcock, R.S. [and others

    1995-11-01

    Several improvements have been developed for the BNCT radiation treatment planning environment (BNCT-Rtpe) during 1994. These improvements have been incorporated into Version 1.0 of BNCT-Rtpe which is currently installed at the INEL, BNL, Japanese Research Center (JRC), and Finland`s Technical Research Center. Platforms supported by this software include Hewlett-Packard (HP), SUN, International Business Machines (IBM), and Silicon Graphics Incorporated (SGI). A draft version of the BNCT-Rtpe user manual is available. Version 1.1 of BNCT-Rtpe is scheduled for release in March 1995. It is anticipated that Version 2.x of BNCT-Rtpe, which includes the nonproprietary NURBS library and data structures, will be released in September 1995.

  20. Surface treatment of CFRP composites using femtosecond laser radiation

    Science.gov (United States)

    Oliveira, V.; Sharma, S. P.; de Moura, M. F. S. F.; Moreira, R. D. F.; Vilar, R.

    2017-07-01

    In the present work, we investigate the surface treatment of carbon fiber-reinforced polymer (CFRP) composites by laser ablation with femtosecond laser radiation. For this purpose, unidirectional carbon fiber-reinforced epoxy matrix composites were treated with femtosecond laser pulses of 1024 nm wavelength and 550 fs duration. Laser tracks were inscribed on the material surface using pulse energies and scanning speeds in the range 0.1-0.5 mJ and 0.1-5 mm/s, respectively. The morphology of the laser treated surfaces was investigated by field emission scanning electron microscopy. We show that, by using the appropriate processing parameters, a selective removal of the epoxy resin can be achieved, leaving the carbon fibers exposed. In addition, sub-micron laser induced periodic surface structures (LIPSS) are created on the carbon fibers surface, which may be potentially beneficial for the improvement of the fiber to matrix adhesion in adhesive bonds between CFRP parts.

  1. Rounded leaf end effect of multileaf collimator on penumbra width and radiation field offset: an analytical and numerical study

    Directory of Open Access Journals (Sweden)

    Zhou Dong

    2015-09-01

    Full Text Available Background. Penumbra characteristics play a significant role in dose delivery accuracy for radiation therapy. For treatment planning, penumbra width and radiation field offset strongly influence target dose conformity and organ at risk sparing.

  2. Conformal house

    DEFF Research Database (Denmark)

    Ryttov, Thomas Aaby; Sannino, Francesco

    2010-01-01

    fixed point. As a consistency check we recover the previously investigated bounds of the conformal windows when restricting to a single matter representation. The earlier conformal windows can be imagined to be part now of the new conformal house. We predict the nonperturbative anomalous dimensions...... at the infrared fixed points. We further investigate the effects of adding mass terms to the condensates on the conformal house chiral dynamics and construct the simplest instanton induced effective Lagrangian terms...

  3. 21 CFR 579.22 - Ionizing radiation for treatment of animal diets.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ionizing radiation for treatment of animal diets... for treatment of animal diets. Ionizing radiation for treatment of complete diets for animals may be... Bagged complete diets, packaged feeds, feed ingredients, bulk feeds, animal treats and chews...

  4. Treatment of advanced head and neck cancer: multiple daily dose fractionated radiation therapy and sequential multimodal treatment approach.

    Science.gov (United States)

    Nissenbaum, M; Browde, S; Bezwoda, W R; de Moor, N G; Derman, D P

    1984-01-01

    Fifty-eight patients with advanced head and neck cancer were entered into a randomised trial comparing chemotherapy (DDP + bleomycin) alone, multiple daily fractionated radiation therapy, and multimodality therapy consisting of chemotherapy plus multiple fractionated radiation therapy. Multimodal therapy gave a significantly higher response rate (69%) than either single-treatment modality. The use of a multiple daily dose fractionation allowed radiation therapy to be completed over 10 treatment days, and the addition of chemotherapy to the radiation treatment did not significantly increase toxicity. Patients receiving multimodal therapy also survived significantly longer (median 50 weeks) than those receiving single-modality therapy (median 24 weeks).

  5. SU-E-J-86: Functional Conformal Planning for Stereotactic Body Radiation Therapy with CT-Pulmonary Ventilation Imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kurosawa, T; Moriya, S; Sato, M [Komazawa University, Setagaya, Tokyo (Japan); Tachibana, H [National Cancer Center Hospital East, Kashiwa, Chiba (Japan)

    2015-06-15

    Purpose: To evaluate the functional planning using CT-pulmonary ventilation imaging for conformal SBRT. Methods: The CT-pulmonary ventilation image was generated using the Jacobian metric in the in-house program with the NiftyReg software package. Using the ventilation image, the normal lung was split into three lung regions for functionality (high, moderate and low). The anatomical plan (AP) and functional plan (FP) were made for ten lung SBRT patients. For the AP, the beam angles were optimized with the dose-volume constraints for the normal lung sparing and the PTV coverage. For the FP, the gantry angles were also optimized with the additional constraint for high functional lung. The MLC aperture shapes were adjusted to the PTV with the additional 5 mm margin. The dosimetric parameters for PTV, the functional volumes, spinal cord and so on were compared in both plans. Results: Compared to the AP, the FP showed better dose sparing for high- and moderate-functional lungs with similar PTV coverage while not taking care of the low functional lung (High:−12.9±9.26% Moderate: −2.0±7.09%, Low: +4.1±12.2%). For the other normal organs, the FP and AP showed similar dose sparing in the eight patients. However, the FP showed that the maximum doses for spinal cord were increased with the significant increment of 16.4Gy and 21.0Gy in other two patients, respectively. Because the beam direction optimizer chose the unexpected directions passing through the spinal cord. Conclusion: Even the functional conformal SBRT can selectively reduce high- and moderatefunctional lung while keeping the PTV coverage. However, it would be careful that the optimizer would choose unexpected beam angles and the dose sparing for the other normal organs can be worse. Therefore, the planner needs to control the dose-volume constraints and also limit the beam angles in order to achieve the expected dose sparing and coverage.

  6. Predictors of urinary and rectal toxicity after external conformed radiation therapy in prostate cancer: Correlation between clinical, tumour and dosimetric parameters and radical and postoperative radiation therapy.

    Science.gov (United States)

    Martínez-Arribas, C M; González-San Segundo, C; Cuesta-Álvaro, P; Calvo-Manuel, F A

    2017-06-15

    To determine rectal and urinary toxicity after external beam radiation therapy (EBRT), assessing the results of patients who undergo radical or postoperative therapy for prostate cancer (pancreatic cancer) and their correlation with potential risk factors. A total of 333 patients were treated with EBRT. Of these, 285 underwent radical therapy and 48 underwent postoperative therapy (39 cases of rescue and 9 of adjuvant therapy). We collected clinical, tumour and dosimetric variable to correlate with toxicity parameters. We developed decision trees based on the degree of statistical significance. The rate of severe acute toxicity, both urinary and rectal, was 5.4% and 1.5%, respectively. The rate of chronic toxicity was 4.5% and 2.7%, respectively. Twenty-seven patients presented haematuria, and 9 presented haemorrhagic rectitis. Twenty-five patients (7.5%) presented permanent limiting sequela. The patients with lower urinary tract symptoms prior to the radiation therapy presented poorer tolerance, with greater acute bladder toxicity (P=0.041). In terms of acute rectal toxicity, 63% of the patients with mean rectal doses >45Gy and anticoagulant/antiplatelet therapy developed mild toxicity compared with 37% of the patients with mean rectal doses <45 Gy and without anticoagulant therapy. We were unable to establish predictors of chronic toxicity in the multivariate analysis. The long-term sequelae were greater in the patients who underwent urological operations prior to the radiation therapy and who were undergoing anticoagulant therapy. The tolerance to EBRT was good, and severe toxicity was uncommon. Baseline urinary symptoms constitute the predictor that most influenced the acute urinary toxicity. Rectal toxicity is related to the mean rectal dose and with anticoagulant/antiplatelet therapy. There were no significant differences in severe toxicity between radical versus postoperative radiation therapy. Copyright © 2017 AEU. Publicado por Elsevier España, S

  7. Optimizing global liver function in radiation therapy treatment planning

    Science.gov (United States)

    Wu, Victor W.; Epelman, Marina A.; Wang, Hesheng; Romeijn, H. Edwin; Feng, Mary; Cao, Yue; Ten Haken, Randall K.; Matuszak, Martha M.

    2016-09-01

    Liver stereotactic body radiation therapy (SBRT) patients differ in both pre-treatment liver function (e.g. due to degree of cirrhosis and/or prior treatment) and radiosensitivity, leading to high variability in potential liver toxicity with similar doses. This work investigates three treatment planning optimization models that minimize risk of toxicity: two consider both voxel-based pre-treatment liver function and local-function-based radiosensitivity with dose; one considers only dose. Each model optimizes different objective functions (varying in complexity of capturing the influence of dose on liver function) subject to the same dose constraints and are tested on 2D synthesized and 3D clinical cases. The normal-liver-based objective functions are the linearized equivalent uniform dose (\\ell \\text{EUD} ) (conventional ‘\\ell \\text{EUD} model’), the so-called perfusion-weighted \\ell \\text{EUD} (\\text{fEUD} ) (proposed ‘fEUD model’), and post-treatment global liver function (GLF) (proposed ‘GLF model’), predicted by a new liver-perfusion-based dose-response model. The resulting \\ell \\text{EUD} , fEUD, and GLF plans delivering the same target \\ell \\text{EUD} are compared with respect to their post-treatment function and various dose-based metrics. Voxel-based portal venous liver perfusion, used as a measure of local function, is computed using DCE-MRI. In cases used in our experiments, the GLF plan preserves up to 4.6 % ≤ft(7.5 % \\right) more liver function than the fEUD (\\ell \\text{EUD} ) plan does in 2D cases, and up to 4.5 % ≤ft(5.6 % \\right) in 3D cases. The GLF and fEUD plans worsen in \\ell \\text{EUD} of functional liver on average by 1.0 Gy and 0.5 Gy in 2D and 3D cases, respectively. Liver perfusion information can be used during treatment planning to minimize the risk of toxicity by improving expected GLF; the degree of benefit varies with perfusion pattern. Although fEUD model optimization is computationally inexpensive and

  8. Optimizing global liver function in radiation therapy treatment planning

    Science.gov (United States)

    Wu, Victor W; Epelman, Marina A; Wang, Hesheng; Romeijn, H Edwin; Feng, Mary; Cao, Yue; Haken, Randall K Ten; Matuszak, Martha M

    2017-01-01

    Liver stereotactic body radiation therapy (SBRT) patients differ in both pre-treatment liver function (e.g. due to degree of cirrhosis and/or prior treatment) and radiosensitivity, leading to high variability in potential liver toxicity with similar doses. This work investigates three treatment planning optimization models that minimize risk of toxicity: two consider both voxel-based pre-treatment liver function and local-function-based radiosensitivity with dose; one considers only dose. Each model optimizes different objective functions (varying in complexity of capturing the influence of dose on liver function) subject to the same dose constraints and are tested on 2D synthesized and 3D clinical cases. The normal-liver-based objective functions are the linearized equivalent uniform dose (ℓEUD) (conventional ‘ℓEUD model’), the so-called perfusion-weighted ℓEUD (fEUD) (proposed ‘fEUD model’), and post-treatment global liver function (GLF) (proposed ‘GLF model’), predicted by a new liver-perfusion-based dose-response model. The resulting ℓEUD, fEUD, and GLF plans delivering the same target ℓEUD are compared with respect to their post-treatment function and various dose-based metrics. Voxel-based portal venous liver perfusion, used as a measure of local function, is computed using DCE-MRI. In cases used in our experiments, the GLF plan preserves up to 4.6%(7.5%) more liver function than the fEUD (ℓEUD) plan does in 2D cases, and up to 4.5%(5.6%) in 3D cases. The GLF and fEUD plans worsen in ℓEUD of functional liver on average by 1.0 Gy and 0.5 Gy in 2D and 3D cases, respectively. Liver perfusion information can be used during treatment planning to minimize the risk of toxicity by improving expected GLF; the degree of benefit varies with perfusion pattern. Although fEUD model optimization is computationally inexpensive and often achieves better GLF than ℓEUD model optimization does, the GLF model directly optimizes a more clinically

  9. Molecular targeted treatment and radiation therapy for rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Marquardt, Friederike; Roedel, Franz; Capalbo, Gianni; Weiss, Christian; Roedel, Claus [Dept. of Radiation Therapy, Univ. of Frankfurt/Main (Germany)

    2009-06-15

    Background: EGFR (epidermal growth factor receptor) and VEGF (vascular endothelial growth factor) inhibitors confer clinical benefit in metastatic colorectal cancer when combined with chemotherapy. An emerging strategy to improve outcomes in rectal cancer is to integrate biologically active, targeted agents as triple therapy into chemoradiation protocols. Material and methods: cetuximab and bevacizumab have now been incorporated into phase I-II studies of preoperative chemoradiation therapy (CRT) for rectal cancer. The rationale of these combinations, early efficacy and toxicity data, and possible molecular predictors for tumor response are reviewed. Computerized bibliographic searches of Pubmed were supplemented with hand searches of reference lists and abstracts of ASCO and ASTRO meetings. Results: the combination of cetuximab and CRT can be safely applied without dose compromises of the respective treatment components. Disappointingly low rates of pathologic complete remission have been noted in several phase II studies. The K-ras mutation status and the gene copy number of EGFR may predict tumor response. The toxicity pattern (radiation-induced enteritis, perforations) and surgical complications (wound healing, fistula, bleeding) observed in at least some of the clinical studies with bevacizumab and CRT warrant further investigations. Conclusion: longer follow-up (and, finally, randomized trials) is needed to draw any firm conclusions with respect to local and distant failure rates, and toxicity associated with these novel treatment approaches. (orig.)

  10. Primary radiation therapy in the treatment of anal carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cantril, S.T. (Children' s Hospital of San Francisco, CA); Green, J.P.; Schall, G.L.; Schaupp, W.C.

    1983-09-01

    From 1966 to 1981, 47 patients with a diagnosis of anal carcinoma were irradiated. This group was composed of 23 males and 24 females, with age ranging from 38 to 84 years (average 64.4 years). Five patients were treated preoperatively and 34 were treated definitively with cancericidal doses of irradiation. Acute radiation reactions requiring a rest-break were noted in 28% of patients, but all were managed as outpatients without untoward chronic sequelae. Chronic complications were noted in 13 patients, including two patients who required colostomy for severe anal stenosis and two who required A-P resection for large painful ulcers. Twenty-eight of 35 patients (80%) treated with irradiation alone have remained locally controlled without further treatment. An additional four have been salvaged by surgery. Only three patients had interstitial implants as part of their treatment course. Actuarial survival at five years for the N/sub 0/ patients and the group as a whole are 95.6 and 79.3%, respectively. It is concluded that external beam irradiation alone, properly fractionated to cancericidal doses, can control anal carcinoma with acceptable morbidity rates and without the use of either chemotherapy or interstitial implants in most cases. There is also a strong correlation suggesting that anal intercourse and male homosexuality play a significant role in the etiology of this disease.

  11. Three-dimensional conformal radiotherapy in the treatment of prostate cancer in Australia and New Zealand: Report on a survey of radiotherapy centres and the proceedings of a consensus workshop.

    Science.gov (United States)

    Tai, K-H; Duchesne, G; Turner, S; Kneebone, A; See, A; Gogna, K; Berry, M

    2004-12-01

    There is an increasing use of 3-D conformal radiotherapy (3DCRT) in the radiotherapeutic management of prostate cancer. The Faculty of Radiation Oncology Genito-Urinary Group carried out a survey of Australian and New Zealand radiotherapy centres in the preparation of a consensus workshop. Of the 19 centres that were represented, there were 24 radiation oncologists, 16 radiation therapists and 12 medical physicists. The survey collected demographic information and data on the practices undertaken at those centres when delivering curative radiotherapy in the treatment of prostate cancer. There was much variation in the delivery of treatment in the areas of patient set-up, contouring of target volumes and organs of interest during computer planning, the techniques and the dose constraints used in these techniques, the use of adjuvant androgen deprivation therapy and the quality assurance processes used in monitoring effects of treatment. This variability reflects the range of data in the published literature. Emerging trends of practices were also identified. This is a first report on a multi-disciplinary approach to the development of guidelines in 3DCRT of prostate cancer.

  12. Proton Radiation Therapy for the Treatment of Retinoblastoma

    Energy Technology Data Exchange (ETDEWEB)

    Mouw, Kent W. [Harvard Radiation Oncology Program, Boston, Massachusetts (United States); Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Sethi, Roshan V.; Yeap, Beow Y.; MacDonald, Shannon M.; Chen, Yen-Lin E.; Tarbell, Nancy J.; Yock, Torunn I.; Munzenrider, John E.; Adams, Judith [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Grabowski, Eric [Department of Pediatrics, Massachusetts General Hospital, Boston, Massachusetts (United States); Mukai, Shizuo [Retina Service, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts (United States); Shih, Helen A., E-mail: hshih@partners.org [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2014-11-15

    Purpose: To investigate long-term disease and toxicity outcomes for pediatric retinoblastoma patients treated with proton radiation therapy (PRT). Methods and Materials: This is a retrospective analysis of 49 retinoblastoma patients (60 eyes) treated with PRT between 1986 and 2012. Results: The majority (84%) of patients had bilateral disease, and nearly half (45%) had received prior chemotherapy. At a median follow-up of 8 years (range, 1-24 years), no patients died of retinoblastoma or developed metastatic disease. The post-PRT enucleation rate was low (18%), especially in patients with early-stage disease (11% for patients with International Classification for Intraocular Retinoblastoma [ICIR] stage A-B disease vs 23% for patients with ICIR stage C-D disease). Post-PRT ophthalmologic follow-up was available for 61% of the preserved eyes (30 of 49): 14 of 30 eyes (47%) had 20/40 visual acuity or better, 7 of 30 (23%) had moderate visual acuity (20/40-20/600), and 9 of 30 (30%) had little or no useful vision (worse than 20/600). Twelve of 60 treated eyes (20%) experienced a post-PRT event requiring intervention, with cataracts the most common (4 eyes). No patients developed an in-field second malignancy. Conclusions: Long-term follow-up of retinoblastoma patients treated with PRT demonstrates that PRT can achieve high local control rates, even in advanced cases, and many patients retain useful vision in the treated eye. Treatment-related ocular side effects were uncommon, and no radiation-associated malignancies were observed.

  13. Surgical management of vestibular schwannomas after failed radiation treatment.

    Science.gov (United States)

    Nonaka, Yoichi; Fukushima, Takanori; Watanabe, Kentaro; Friedman, Allan H; Cunningham, Calhoun D; Zomorodi, Ali R

    2016-04-01

    Increasing numbers of patients with vestibular schwannoma (VS) have been treated with focused-beam stereotactic radiation treatment (SRT) including Gamma knife, CyberKnife, X-knife, Novalis, or proton beam therapy. The purpose of this study was to document the incidence of tumor regrowth or symptoms that worsened or first developed following SRT and to discuss surgical strategies for patients who have failed SRT for VS. A consecutive series of 39 patients with SRT failed VS were surgically treated. Clinical symptoms, tumor regrowth at follow-up, intraoperative findings, and surgical outcome were evaluated. There were 15 males and 24 females with a mean age of 51.8 years. Thirty-six patients (92.3%) demonstrated steady tumor growth after SRT. Two (5.1%) patients with slight increase of the mass underwent surgical resection because of development of unbearable facial pain. Symptoms that worsened or newly developed following SRT in this series were deafness (41%), dizziness (35.9%), facial numbness (25.6%), tinnitus (20.5%), facial nerve palsy (7.7%), and facial pain (7.7%). Intraoperative findings demonstrated fibrous changes of the tumor mass, cyst formation, and brownish-yellow or purple discoloration of the tumor capsule. Severe adhesions between the tumor capsule and cranial nerves, vessels, and the brainstem were observed in 69.2%. Additionally, the facial nerve was more fragile and irritable in all cases. Gross total resection (GTR) was achieved in 33.3% of patients, near-total resection (NTR) in 35.9%, and subtotal resection (STR) in 30.8% of patients. New facial nerve palsy was seen in seven patients (19.4%) postoperatively. Our findings suggest that patients with VS who fail SRT with either tumor progression or worsening of clinical symptoms will have an increased rate of adhesions to the neurovascular structures and may have radiation-influenced neuromalacia. Salvage surgery of radiation-failed tumors is more difficult and will have a higher risk of

  14. Intensity-Modulated Radiotherapy Causes Fewer Side Effects than Three-Dimensional Conformal Radiotherapy When Used in Combination With Brachytherapy for the Treatment of Prostate Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Forsythe, Kevin; Blacksburg, Seth [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States); Stone, Nelson [Department of Urology, Mount Sinai School of Medicine, New York, NY (United States); Stock, Richard G., E-mail: richard.stock@moutsinai.org [Department of Radiation Oncology, Mount Sinai School of Medicine, New York, NY (United States)

    2012-06-01

    Purpose: To measure the benefits of intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3D-CRT) when used in combination with brachytherapy for the treatment of prostate cancer. Methods and Materials: We conducted a retrospective review of all patients with localized prostate cancer who received external-beam radiotherapy (EBRT) in combination with brachytherapy with at least 1 year follow-up (n = 812). Combination therapy consisted of {sup 103}Pd or {sup 125}I implant, followed by a course of EBRT. From 1993 to March 2003 521 patients were treated with 3D-CRT, and from April 2003 to March 2009 291 patients were treated with IMRT. Urinary symptoms were prospectively measured with the International Prostate Symptom Score questionnaire with a single quality of life (QOL) question; rectal bleeding was assessed per the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer Late Radiation Morbidity Scoring Schema. The Pearson {chi}{sup 2} test was used to compare toxicities experienced by patients who were treated with either IMRT or 3D-CRT. Logistic regression analyses were also performed to rule out possible confounding factors. Results: Within the first 3 months after treatment, patients treated with 3D-CRT scored their urinary symptoms as follows: 19% mild, 44% moderate, and 37% severe; patients treated with IMRT scored their urinary symptoms as follows: 36% mild, 47% moderate, and 17% severe (p < 0.001). The 3D-CRT patients rated their QOL as follows: 35% positive, 20% neutral, and 45% negative; IMRT patients rated their QOL as follows: 51% positive, 18% neutral, and 31% negative (p < 0.001). After 1 year of follow-up there was no longer any difference in urinary morbidity between the two groups. Logistic regression confirmed the differences in International Prostate Symptom Score and QOL in the acute setting (p < 0.001 for both). Grade {>=}2 rectal bleeding was reported by 11% of 3D

  15. Radiation safety issues in the water treatment plant - Indoor radon and gamma radiation

    Energy Technology Data Exchange (ETDEWEB)

    Jantsikene, A.; Kiisk, M.; Suursoo, S.; Koch, R. [University of Tartu, Institute of Physics (Estonia); Lumiste, L. [Tallinn University of Technology, Department of Chemical Engineering (Estonia)

    2014-07-01

    In order to reduce the indicative dose from drinking water consumption in Viimsi parish, Estonia, a new water treatment plant was launched in 2012 serving about 15 000 consumers. The promising new technology for groundwater purification consists of air injector, oxidation tank, patented venturi-type centrifugal degassing separation unit GDT and two-stage filtration in open filter columns. In each of the five parallel lines, approximately 95 tons of catalytic (FMH and sand) and 45 tons of non-catalytic (zeolite) filter materials were used. These filter materials proved to be very effective adsorbents of incoming radium isotopes. As a result, the columns emit direct gamma radiation. Moreover, columns' exposure to indoor air makes them radon generators that affect all rooms in the building. During the study period of two years the filter materials were not replaced and their lifespan has not been estimated yet. In order to minimize radiation risks for the workers inside the water treatment plant, a complex study and a long-term monitoring is needed. For the measurements of {sup 226}Ra and {sup 228}Ra concentrations in water and in solid filter materials gamma-ray spectroscopy was used. According to the results, the annual input of {sup 226}Ra and {sup 228}Ra is 325 MBq and 420 MBq, respectively. The average incoming concentration of {sup 226}Ra and {sup 228}Ra isotopes is 0.5 Bq/L and 0.6 Bq/L, respectively, and the radium content in the output water is below the limit of detection (about 10-15 mBq/L). This means strong accumulation of radium isotopes in the filter materials, thus causing an increase of {sup 222}Rn concentrations in the outgoing treated water. External dose rates throughout the length of the filter columns were measured with the portable dosimeter to estimate the {sup 226}Ra and {sup 228}Ra depth distribution. The results showed that distribution of these radionuclides is uneven with the maximum of 0.5 μSv/h for the first stage and 3 μSv/h for

  16. Correlation of Conformational Changes and Protein Degradation with Loss of Lysozyme Activity Due to Chlorine Dioxide Treatment.

    Science.gov (United States)

    Ooi, Beng Guat; Branning, Sharon Alyssa

    2016-12-13

    Chlorine dioxide (ClO2) is a potent oxidizing agent used for the treatment of drinking water and decontamination of facilities and equipment. The purpose of this research is to elucidate the manner in which ClO2 destroys proteins by studying the effects of ClO2 on lysozyme. The degree of enzyme activity lost can be correlated to the treatment time and levels of the ClO2 used. Lysozyme activity was drastically reduced to 45.3% of original enzyme activity when exposed to 4.3 mM ClO2 in the sample after 3 h. Almost all activities were lost in 3 h after exposure to higher ClO2 concentrations of up to 16.8 and 21.9 mM. Changes in protein conformation and amount as a result of ClO2 treatment were determined using the Raman spectroscopy and gel electrophoresis. Raman shifts and the alteration of spectral features observed in the ClO2-treated lysozyme samples are associated with loss of the α-helix secondary structure, tertiary structure, and disulfide bond. Progressive degradation of the denatured lysozyme by increasing levels of chlorine dioxide was also observed in gel electrophoresis. Hence, ClO2 can effectively cause protein denaturation and degradation resulting in loss of enzyme activity.

  17. Pilot study of systemic and intrathecal mafosfamide followed by conformal radiation for infants with intracranial central nervous system tumors: a pediatric brain tumor consortium study (PBTC-001).

    Science.gov (United States)

    Blaney, Susan M; Kocak, Mehmet; Gajjar, Amar; Chintagumpala, Murali; Merchant, Thomas; Kieran, Mark; Pollack, Ian F; Gururangan, Sri; Geyer, Russ; Phillips, Peter; McLendon, Roger E; Packer, Roger; Goldman, Stewart; Banerjee, Anu; Heideman, Richard; Boyett, James M; Kun, Larry

    2012-09-01

    A pilot study to investigate the feasibility of the addition of intrathecal (IT) mafosfamide to a regimen of concomitant multi-agent systemic chemotherapy followed by conformal radiation therapy (RT) for children systemic multi-agent chemotherapy commenced within 35 days of surgery. Patients without CSF flow obstruction (n = 71) received IT mafosfamide (14 mg) with chemotherapy. Localized (M(0)) patients with SD or better subsequently received RT followed by 20 additional weeks of chemotherapy. Second look surgery was encouraged prior to RT if there was an incomplete surgical resection at diagnosis. 71 evaluable patients with normal CSF flow received IT Mafosfamide with systemic chemotherapy; patients with M + disease were removed from protocol therapy at 20 weeks and those with PD at the time of progression. One and 5-year progression free survival (PFS) and overall survival (OS) for the cohort of 71 evaluable patients were 52 ± 6.5 % and 33 ± 13 %, and 67 ± 6.2 % and 51 ± 11 %, respectively. The 1-year Progression Free Survival (PFS) for M0 patients with medulloblastoma (MB, n = 20), supratentorial primitive neuroectodermal tumor (PNET, n = 9), and atypical teratoid rhabdoid tumor (ATRT, n = 12) was 80 ± 7 %, 67 ± 15 % and 27 ± 13 % and 5-year PFS was 65 ± 19 %, 37 ± 29 %, and 0 ± 0 %, respectively. The addition of IT mafosfamide to systemic chemotherapy in infants with embryonal CNS tumors was feasible. The PFS for M0 patients appears comparable to or better than most prior historical comparisons and was excellent for those receiving conformal radiotherapy.

  18. Reducing the Human Burden of Breast Cancer: Advanced Radiation Therapy Yields Improved Treatment Outcomes.

    Science.gov (United States)

    Currey, Adam D; Bergom, Carmen; Kelly, Tracy R; Wilson, J Frank

    2015-01-01

    Radiation therapy is an important modality in the treatment of patients with breast cancer. While its efficacy in the treatment of breast cancer was known shortly after the discovery of x-rays, significant advances in radiation delivery over the past 20 years have resulted in improved patient outcomes. With the development of improved systemic therapy, optimizing local control has become increasingly important and has been shown to improve survival. Better understanding of the magnitude of treatment benefit, as well as patient and biological factors that confer an increased recurrence risk, have allowed radiation oncologists to better tailor treatment decisions to individual patients. Furthermore, significant technological advances have occurred that have reduced the acute and long-term toxicity of radiation treatment. These advances continue to reduce the human burden of breast cancer. It is important for radiation oncologists and nonradiation oncologists to understand these advances, so that patients are appropriately educated about the risks and benefits of this important treatment modality.

  19. Energy loss of ions in a magnetized plasma: conformity between linear response and binary collision treatments.

    Science.gov (United States)

    Nersisyan, H B; Zwicknagel, G; Toepffer, C

    2003-02-01

    The energy loss of a heavy ion moving in a magnetized electron plasma is considered within the linear response (LR) and binary collision (BC) treatments with the purpose to look for a connection between these two models. These two complementary approaches yield close results if no magnetic field is present, but there develop discrepancies with growing magnetic field at ion velocities that are lower than, or comparable with, the thermal velocity of the electrons. We show that this is a peculiarity of the Coulomb interaction which requires cutoff procedures to account for its singularity at the origin and its infinite range. The cutoff procedures in the LR and BC treatments are different as the order of integrations in velocity and in ordinary (Fourier) spaces is reversed in both treatments. While BC involves a velocity average of Coulomb logarithms, there appear in LR Coulomb logarithms of velocity averaged cutoffs. The discrepancies between LR and BC vanish, except for small contributions of collective modes, for smoothened potentials that require no cutoffs. This is shown explicitly with the help of an improved BC in which the velocity transfer is treated up to second order in the interaction in Fourier space.

  20. A prospective dosimetric and clinical comparison of acute hematological toxicities in three-dimensional conformal radiation therapy and intensity modulated radiation therapy with concurrent chemotherapy in carcinoma cervix

    Directory of Open Access Journals (Sweden)

    H U Avinash

    2015-01-01

    Full Text Available Background and Objectives: Acute hematological toxicities are an important cause of morbidity in patients receiving concurrent chemoradiation to pelvis in carcinoma cervix. The objective of this study was to evaluate the role of intensity-modulated radiotherapy (IMRT in reducing the dose to the bone marrow as compared with three-dimensional conformal radiotherapy (3DCRT and hence its impact on reducing the acute hematological toxicities. Materials and Methods: Eleven consecutive patients treated with IMRT and 12 patients treated with 3DCRT to the whole pelvis along with concurrent chemotherapy were selected. Bone marrow was delineated. V10 Gy, V20 Gy, V95%, and Dmean of bone marrow were recorded. Weekly blood counts were recorded and graded as per Common Terminology Criteria version 4.0 for all the patients. Results: The dose to the bone marrow V20 Gy was 206.78 ± 57.10 cc (75% and 251.70 ± 40.45 cc (91% for IMRT and 3DCRT, respectively (P = 0.04 and V95% was 23.30 ± 8.34% and 46.76 ± 6.71% for IMRT and 3DCRT, respectively (P = 0.001. The grade of toxicities during each week did not show the difference in either arm. However, the total count and Neutrophil counts during the 2nd week showed statistical significance between IMRT and 3DCRT. Conclusion: IMRT significantly reduces the dose to the bone marrow as compared to 3DCRT. The reduction of the dose did not translate into a decrease in acute hematological toxicities. Concurrent platinum-based chemotherapy is the probable cause for the hematological toxicities.

  1. Experimental treatment of radiation pneumonitis with human umbilical cord mesenchymal stem cells

    Institute of Scientific and Technical Information of China (English)

    Rui Wang; Chang-zheng Zhu; Ping Qiao; Jian Liu; Qiang Zhao; Kui-jie Wang; Ting-bao Zhao

    2014-01-01

    Objective: To evaluate of the curative effect of human umbilical cord mesenchymal stem cells (hUC-MSCs) on rat acute radiation pneumonitis. Methods: Fourty rats were randomly divided into control group, radiation group, stem cell prevention group, stem cell treatment group and prednisone treatment group. All rats except those in the control group were radiated with X ray to establish the acute radiation pneumonitis damage model. The hUC-MSCs cultured in vitro was administrated to the rats of the prevention group via tail vein (1×106 cells/kg BW) 24 h before the radiation, while the same administration was performed in the rats of the treatment group 24 h after the radiation. After 24 h post the radiation, the rats in the radiation group were given 0.4 mL physiological saline, and those in the prednisone group were given 1 mg/kg prednisone. All rats were observed and executed 72 h after the radiation to detect lung histological changes. Results:After the administration of hUC-MSCs, the survival status of the rats in the prevention group and treatment group was obviously better than that in the control group. As shown by the histological staining, the morphology, proliferation activity and bronchial state of lung tissues were better in the prevention group and treatment group than in the control group. Conclusion: The hUC-MSCs have definite therapeutic effects on acute radiation pneumonitis in rats.

  2. Protein conformational modulation by photons: a mechanism for laser treatment effects.

    Science.gov (United States)

    Liebert, Ann D; Bicknell, Brian T; Adams, Roger D

    2014-03-01

    Responsiveness to low-level laser treatment (LLTT) at a wavelength of 450-910 nm has established it as an effective treatment of medical, veterinary and dental chronic pain, chronic inflammation conditions (arthritis and macular degeneration), wound repair, and lymphoedema, yet the mechanisms underlying the effectiveness of LLLT remain unclear. However, there is now sufficient evidence from recent research to propose an integrated model of LLLT action. The hypothesis presented in this paper is that external applications of photons (through laser at an appropriate dose) modulates the nervous system through an integrated mechanism. This stimulated mechanism involves protein-to-protein interaction, where two or more proteins bind together to facilitate molecular processes, including modification of proteins by members of SUMO (small ubiquitin-related modifier proteins) and also protein phosphorylation and tyrosination. SUMO has been shown to have a role in multiple nuclear and perinuclear targets, including ion channels, and in the maintenance of telomeres and the post-translational modification of genes. The consequence of laser application in treatment, therefore, can be seen as influencing the transmission of neural information via an integrated and rapid modulation of ion channels, achieved through both direct action on photo-acceptors (such as cytochrome c-oxidase) and through indirect modulation via enzymes, including tyrosine hydroxylase (TH), tyrosine kinases and tyrosine kinase receptors. This exogenous action then facilitates an existing photonic biomodulation mechanism within the body, and initiates ion channel modulation both in the periphery and the central nervous system (CNS). Evidence indicates that the ion channel modulation functions predominately through the potassium channels, including two pore leak channels (K2P), which act as signal integrators from the periphery to the cortex. Photonic action also transforms SUMOylation processes at the cell

  3. Clinical Outcome of Patients Treated With 3D Conformal Radiation Therapy (3D-CRT) for Prostate Cancer on RTOG 9406

    Energy Technology Data Exchange (ETDEWEB)

    Michalski, Jeff, E-mail: michalski@wustl.edu [Radiation Oncology, Washington University Medical School, St. Louis, Missouri (United States); Image-guided Therapy Center, St. Louis, Missouri (United States); Winter, Kathryn [Department of Statistics, Radiation Therapy Oncology Group, Philadelphia, Pennsylvania (United States); Roach, Mack [Radiation Oncology, University of California-San Francisco, San Francisco, California (United States); Markoe, Arnold [University of Miami, Miami, Florida (United States); Sandler, Howard M. [University of Michigan, Ann Arbor, Michigan (United States); Cedars-Sinai Medical Center, Los Angeles, California (United States); Ryu, Janice [Radiation Oncology, University of California-Davis, Davis, California (United States); Radiation Oncology Associates, Sacramento, California (United States); Parliament, Matthew [Radiation Oncology, University of Alberta, Edmonton, Alberta (Canada); Purdy, James A. [Radiation Oncology, University of California-Davis, Davis, California (United States); Image-guided Therapy Center, St. Louis, Missouri (United States); Valicenti, Richard K. [Radiation Oncology, University of California-Davis, Davis, California (United States); Thomas Jefferson University, Philadelphia, Pennsylvania (United States); Cox, James D. [Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-07-01

    Purpose: Report of clinical cancer control outcomes on Radiation Therapy Oncology Group (RTOG) 9406, a three-dimensional conformal radiation therapy (3D-CRT) dose escalation trial for localized adenocarcinoma of the prostate. Methods and Materials: RTOG 9406 is a Phase I/II multi-institutional dose escalation study of 3D-CRT for men with localized prostate cancer. Patients were registered on five sequential dose levels: 68.4 Gy, 73.8 Gy, 79.2 Gy, 74 Gy, and 78 Gy with 1.8 Gy/day (levels I-III) or 2.0 Gy/day (levels IV and V). Neoadjuvant hormone therapy (NHT) from 2 to 6 months was allowed. Protocol-specific, American Society for Therapeutic Radiation Oncology (ASTRO), and Phoenix biochemical failure definitions are reported. Results: Thirty-four institutions enrolled 1,084 patients and 1,051 patients are analyzable. Median follow-up for levels I, II, III, IV, and V was 11.7, 10.4, 11.8, 10.4, and 9.2 years, respectively. Thirty-six percent of patients received NHT. The 5-year overall survival was 90%, 87%, 88%, 89%, and 88% for dose levels I-V, respectively. The 5-year clinical disease-free survival (excluding protocol prostate-specific antigen definition) for levels I-V is 84%, 78%, 81%, 82%, and 82%, respectively. By ASTRO definition, the 5-year disease-free survivals were 57%, 59%, 52%, 64% and 75% (low risk); 46%, 52%, 54%, 56%, and 63% (intermediate risk); and 50%, 34%, 46%, 34%, and 61% (high risk) for levels I-V, respectively. By the Phoenix definition, the 5-year disease-free survivals were 68%, 73%, 67%, 84%, and 80% (low risk); 70%, 62%, 70%, 74%, and 69% (intermediate risk); and 42%, 62%, 68%, 54%, and 67% (high risk) for levels I-V, respectively. Conclusion: Dose-escalated 3D-CRT yields favorable outcomes for localized prostate cancer. This multi-institutional experience allows comparison to other experiences with modern radiation therapy.

  4. Radiation recall dermatitis after docetaxel chemotherapy. Treatment by antioxidant ointment

    Energy Technology Data Exchange (ETDEWEB)

    Duncker-Rohr, Viola; Freund, Ulrich; Momm, Felix [Ortenau-Klinikum Offenburg-Gengenbach Lehrkrankenhaus der Albert-Ludwigs-Universitaet Freiburg i. Br., Radio-Onkologie, Offenburg (Germany)

    2014-05-15

    Radiation recall dermatitis (RRD) is an acute skin toxicity caused by different anticancer or antibiotic drugs within a former completely healed irradiation field. Predictive factors for RRD are not known and its mechanisms are not completely understood. A case of RRD induced by docetaxel and successfully treated by an antioxidant ointment (Mapisal {sup registered}) is presented here. Such an ointment might be useful not only in RRD therapy, but also in the treatment of high-grade dermatitis induced by radiotherapy and thus may contribute to the improvement of patients' quality of life and to the scheduled completion of cancer therapies. (orig.) [German] Die Strahlen-Recall-Dermatitis (RRD) ist eine akute Hauttoxizitaet, die durch verschiedene Chemotherapeutika oder Antibiotika innerhalb eines frueheren, komplett abgeheilten Bestrahlungsfelds hervorgerufen wird. Praediktive Faktoren fuer die RRD sind nicht bekannt und ihr Mechanismus ist nicht vollstaendig geklaert. Es wird ein Fallbericht einer durch Docetaxel induzierten RRD dargestellt, die erfolgreich mit einer antioxidativen Salbe (Mapisal {sup registered}) behandelt wurde. Solche Salben koennten nicht nur zur Therapie der RRD, sondern auch bei der Behandlung einer akuten Dermatitis waehrend der Strahlentherapie nuetzlich sein und damit zur Verbesserung der Lebensqualitaet der Patienten und zur planmaessigen Durchfuehrung der Tumortherapie beitragen. (orig.)

  5. Microdosimetry of DNA conformations: relation between direct effect of (60)Co gamma rays and topology of DNA geometrical models in the calculation of A-, B- and Z-DNA radiation-induced damage yields.

    Science.gov (United States)

    Semsarha, Farid; Raisali, Gholamreza; Goliaei, Bahram; Khalafi, Hossein

    2016-05-01

    In order to obtain the energy deposition pattern of ionizing radiation in the nanometric scale of genetic material and to investigate the different sensitivities of the DNA conformations, direct effects of (60)Co gamma rays on the three A, B and Z conformations of DNA have been studied. For this purpose, single-strand breaks (SSB), double-strand breaks (DSB), base damage (BD), hit probabilities and three microdosimetry quantities (imparted energy, mean chord length and lineal energy) in the mentioned DNA conformations have been calculated and compared by using GEometry ANd Tracking 4 (Geant4) toolkit. The results show that A-, B- and Z-DNA conformations have the highest yields of DSB (1.2 Gy(-1) Gbp(-1)), SSB (25.2 Gy(-1) Gbp(-1)) and BD (4.81 Gy(-1) Gbp(-1)), respectively. Based on the investigation of direct effects of radiation, it can be concluded that the DSB yield is largely correlated to the topological characteristics of DNA models, although the SSB yield is not. Moreover, according to the comparative results of the present study, a reliable candidate parameter for describing the relationship between DNA damage yields and geometry of DNA models in the theoretical radiation biology research studies would be the mean chord length (4 V/S) of the models.

  6. Transportation Conformity

    Science.gov (United States)

    This section provides information on: current laws, regulations and guidance, policy and technical guidance, project-level conformity, general information, contacts and training, adequacy review of SIP submissions

  7. Comparison of volumetric-modulated arc therapy and dynamic conformal arc treatment planning for cranial stereotactic radiosurgery.

    Science.gov (United States)

    Molinier, Jessica; Kerr, Christine; Simeon, Sebastien; Ailleres, Norbert; Charissoux, Marie; Azria, David; Fenoglietto, Pascal

    2016-01-08

    The aim was to analyze arc therapy techniques according to the number and position of the brain lesions reported by comparing dynamic noncoplanar conformal arcs (DCA), two coplanar full arcs (RAC) with volumetric-modulated arc therapy (VMAT), multiple noncoplanar partial arcs with VMAT (RANC), and two full arcs with VMAT and 10° table rotation (RAT). Patients with a single lesion (n= 10), multiple lesions (n = 10) or a single lesion close to organs at risk (n = 5) and previously treated with DCA were selected. For each patient, the DCA treatment was replanned with all VMAT techniques. All DCA plans were compared with VMAT plans and evaluated in regard to the different quality indices and dosimetric parameters. For single lesion, homogeneity index (HI) better results were found for the RANC technique (0.17 ± 0.05) compared with DCA procedure (0.27± 0.05). Concerning conformity index (CI), the RAT technique gave higher and better values (0.85 ± 0.04) compared with those obtained with the DCA technique (0.77 ± 0.05). DCA improved healthy brain protection (8.35 ± 5.61 cc vs. 10.52 ± 6.40 cc for RANC) and reduced monitor unit numbers (3046 ± 374 MU vs. 4651 ± 736 for RANC), even if global room occupation was higher. For multiple lesions, VMAT techniques provided better HI (0.16) than DCA (0.24 ± 0.07). The CI was improved with RAT (0.8 ± 0.08 for RAT vs. 0.71 ± 0.08 for DCA). The V10Gy healthy brain was better protected with DCA (9.27 ± 4.57 cc). Regarding the MU numbers: RANC < RAT< RAC < DCA. For a single lesion close to OAR, RAT achieved high degrees of homogeneity (0.27 ± 0.03 vs. 0.53 ± 0.2 for DCA) and conformity (0.72± 0.06vs. 0.56 ± 0.13 for DCA) while sparing organs at risk (Dmax = 12.36 ± 1.05Gyvs. 14.12 ± 0.59 Gy for DCA, and Dmean = 3.96 ± 3.57Gyvs. 4.72 ± 3.28Gy for DCA). On the other hand, MU numbers were lower with DCA (2254 ± 190 MUvs. 3438 ± 457 MU for RANC) even if overall time was inferior with RAC. For a single lesion, DCA

  8. Elimination of Listeria monocytogenes in sausage meat by combination treatment: Radiation and radiation-resistant bacteriocins

    Science.gov (United States)

    Turgis, Mélanie; Stotz, Viviane; Dupont, Claude; Salmieri, Stéphane; Khan, Ruhul A.; Lacroix, Monique

    2012-08-01

    Two new bacteria were isolated from human feces and were designated MT 104 and MT 162. They were able to produce bacteriocins that are active against five strains of Listeria monocytogenes. Bacteriocins produced by these isolated strains had 100% and 82.35% residual activity when they were treated by gamma radiation at doses of 4 and 40 kGy, respectively. A reduction of 1.0, 1.5 and 3 log CFU/g of L. monocytogenes was observed in sausage meat when treated with bacteriocins from MT 104, MT 162, and nisin, respectively. For synergic effect, the D10 value in presence of the bacteriocins produced by MT 104 showed a 1.08 fold increased relative sensitivity of L. monocytogenes as compared to control after 5 days. The highest synergic effect was observed in presence of nisin which led to 1.61 fold increased relative sensitivity. Combined treatments with nisin and γ-irradiation showed a synergic antimicrobial effect in meat after 24 h and 5 days of storage. A synergic effect was observed only after 5 days at 4 °C for the bacteriocin from MT 104, as compared to the bacteriocin produced by MT 162 that had only an additive antimicrobial effect in all conditions.

  9. Volumetric Spectroscopic Imaging of Glioblastoma Multiforme Radiation Treatment Volumes

    Energy Technology Data Exchange (ETDEWEB)

    Parra, N. Andres [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Maudsley, Andrew A. [Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida (United States); Gupta, Rakesh K. [Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, Haryana (India); Ishkanian, Fazilat; Huang, Kris [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Walker, Gail R. [Biostatistics and Bioinformatics Core Resource, Sylvester Cancer Center, University of Miami Miller School of Medicine, Miami, Florida (United States); Padgett, Kyle [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Department of Radiology, University of Miami Miller School of Medicine, Miami, Florida (United States); Roy, Bhaswati [Department of Radiology and Imaging, Fortis Memorial Research Institute, Gurgaon, Haryana (India); Panoff, Joseph; Markoe, Arnold [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States); Stoyanova, Radka, E-mail: RStoyanova@med.miami.edu [Department of Radiation Oncology, University of Miami Miller School of Medicine, Miami, Florida (United States)

    2014-10-01

    Purpose: Magnetic resonance (MR) imaging and computed tomography (CT) are used almost exclusively in radiation therapy planning of glioblastoma multiforme (GBM), despite their well-recognized limitations. MR spectroscopic imaging (MRSI) can identify biochemical patterns associated with normal brain and tumor, predominantly by observation of choline (Cho) and N-acetylaspartate (NAA) distributions. In this study, volumetric 3-dimensional MRSI was used to map these compounds over a wide region of the brain and to evaluate metabolite-defined treatment targets (metabolic tumor volumes [MTV]). Methods and Materials: Volumetric MRSI with effective voxel size of ∼1.0 mL and standard clinical MR images were obtained from 19 GBM patients. Gross tumor volumes and edema were manually outlined, and clinical target volumes (CTVs) receiving 46 and 60 Gy were defined (CTV{sub 46} and CTV{sub 60}, respectively). MTV{sub Cho} and MTV{sub NAA} were constructed based on volumes with high Cho and low NAA relative to values estimated from normal-appearing tissue. Results: The MRSI coverage of the brain was between 70% and 76%. The MTV{sub NAA} were almost entirely contained within the edema, and the correlation between the 2 volumes was significant (r=0.68, P=.001). In contrast, a considerable fraction of MTV{sub Cho} was outside of the edema (median, 33%) and for some patients it was also outside of the CTV{sub 46} and CTV{sub 60}. These untreated volumes were greater than 10% for 7 patients (37%) in the study, and on average more than one-third (34.3%) of the MTV{sub Cho} for these patients were outside of CTV{sub 60}. Conclusions: This study demonstrates the potential usefulness of whole-brain MRSI for radiation therapy planning of GBM and revealed that areas of metabolically active tumor are not covered by standard RT volumes. The described integration of MTV into the RT system will pave the way to future clinical trials investigating outcomes in patients treated based on

  10. Predictors of grade {>=}2 and grade {>=}3 radiation pneumonitis in patients with locally advanced non-small cell lung cancer treated with three-dimensional conformal radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Dang, Jun; Li, Guang; Ma, Lianghua; Han, Chong; Zhang, Shuo; Yao, Lei [Dept. of Radiation Oncology, The First Hospital of China Medical Univ., Shenyang (China)], e-mail: gl1963516@yahoo.cn; Diao, Rao [Dept. of Experimental Technology Center, China Medical Univ., Shenyang (China); Zang, Shuang [Dept. of Nursing, China Medical Univ., Shenyang (China)

    2013-08-15

    Grade {>=}3 radiation pneumonitis (RP) is generally severe and life-threatening. Predictors of grade {>=}2 are usually used for grade {>=}3 RP prediction, but it is unclear whether these predictors are appropriate. In this study, predictors of grade {>=}2 and grade {>=}3 RP were investigated separately. The increased risk of severe RP in elderly patients compared with younger patients was also evaluated. Material and methods: A total of 176 consecutive patients with locally advanced non-small cell lung cancer were followed up prospectively after three-dimensional conformal radiotherapy. RP was graded according to Common Terminology Criteria for Adverse Events version 3.0. Results: Mean lung dose (MLD), mean heart dose, ratio of planning target volume to total lung volume (PTV/Lung), and dose-volume histogram comprehensive value of both heart and lung were associated with both grade {>=}2 and grade {>=}3 RP in univariate analysis. In multivariate logistic regression analysis, age and MLD were predictors of both grade {>=}2 RP and grade {>=}3 RP; receipt of chemotherapy predicted grade {>=}3 RP only; and sex and PTV/Lung predicted grade {>=}2 RP only. Among patients who developed high-grade RP, MLD and PTV/Lung were significantly lower in patients aged {>=}70 years than in younger patients (p<0.05 for both comparisons). Conclusions: The predictors were not completely consistent between grade {>=}2 RP and grade {>=}3 RP. Elderly patients had a higher risk of severe RP than younger patients did, possibly due to lower tolerance of radiation to the lung.

  11. A Comparison of Helical Intensity-Modulated Radiotherapy, Intensity-Modulated Radiotherapy, and 3D-Conformal Radiation Therapy for Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Poppe, Matthew M.; Narra, Venkat; Yue, Ning J.; Zhou Jinghao; Nelson, Carl [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States); Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States); Jabbour, Salma K., E-mail: jabbousk@umdnj.edu [Department of Radiation Oncology, Huntsman Cancer Hospital, University of Utah, Salt Lake City, UT (United States); Department of Radiation Oncology, Cancer Institute of New Jersey, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, New Brunswick, NJ (United States)

    2011-01-01

    We assessed dosimetric differences in pancreatic cancer radiotherapy via helical intensity-modulated radiotherapy (HIMRT), linac-based IMRT, and 3D-conformal radiation therapy (3D-CRT) with regard to successful plan acceptance and dose to critical organs. Dosimetric analysis was performed in 16 pancreatic cases that were planned to 54 Gy; both post-pancreaticoduodenectomy (n = 8) and unresected (n = 8) cases were compared. Without volume modification, plans met constraints 75% of the time with HIMRT and IMRT and 13% with 3D-CRT. There was no statistically significantly improvement with HIMRT over conventional IMRT in reducing liver V35, stomach V45, or bowel V45. HIMRT offers improved planning target volume (PTV) dose homogeneity compared with IMRT, averaging a lower maximum dose and higher volume receiving the prescription dose (D100). HIMRT showed an increased mean dose over IMRT to bowel and liver. Both HIMRT and IMRT offer a statistically significant improvement over 3D-CRT in lowering dose to liver, stomach, and bowel. The results were similar for both unresected and resected patients. In pancreatic cancer, HIMRT offers improved dose homogeneity over conventional IMRT and several significant benefits to 3D-CRT. Factors to consider before incorporating IMRT into pancreatic cancer therapy are respiratory motion, dose inhomogeneity, and mean dose.

  12. Radiation treatment of materials - elaboration bases of radiation technology; Obrobka radiacyjna materialow - zasady opracowywania technologii

    Energy Technology Data Exchange (ETDEWEB)

    Panta, P.P. [Institute of Nuclear Chemistry and Technology, Warsaw (Poland)

    1997-10-01

    The basic rules in design of radiation technologies have been presented and discussed. The recommendations for achieving of assigned goal in respect of obliged regulations have been done and explained on the example of radiation technology of adhesive materials and glue production.

  13. Changing Attitude Toward Radiation Carcinogenesis and Prospects for Novel Low-Dose Radiation Treatments.

    Science.gov (United States)

    Socol, Yehoshua; Welsh, James S

    2016-12-01

    All procedures involving ionizing radiation, whether diagnostic or therapeutic, are subject to strict regulation, and public concerns have been raised about even the low levels of radiation exposures involved in diagnostic imaging. During the last 2 decades, there are signs of more balanced attitude to ionizing radiation hazards, as opposed to the historical "radiophobia." The linear no-threshold hypothesis, based on the assumption that every radiation dose increment constitutes increased cancer risk for humans, is increasingly debated. In particular, the recent memorandum of the International Commission on Radiological Protection admits that the linear no-threshold hypothesis predictions at low doses (that International Commission on Radiological Protection itself has used and continues to use) are "speculative, unproven, undetectable, and 'phantom'." Moreover, numerous experimental, ecological, and epidemiological studies suggest that low doses of ionizing radiation may actually be beneficial to human health. Although these advances in scientific understanding have not yet yielded significant changes in radiation regulation and policy, we are hopeful such changes may happen in the relatively near future. This article reviews the present status of the low-dose radiation hazard debate and outlines potential opportunities in the field of low-dose radiation therapy. © The Author(s) 2015.

  14. Profiles and Time Course of Acute Radiation Toxicity Symptoms during Conformal Radiotherapy for Cancer of the Prostate

    Energy Technology Data Exchange (ETDEWEB)

    Hovdenak, Nils; Karlsdottir, Aasa; Soerbye, Halfdan; Dahl, Olav [Univ. of Bergen (Norway). Div. of Gastroenterology

    2003-11-01

    Symptoms of gastrointestinal toxicity are dose-limiting for pelvic radiotherapy (RT). Existing toxicity registrations (RTOG/EORTC) are helpful in defining maximal tolerated doses, but tend to underestimate the total toxicity burden by excluding several minor complaints. We have applied a more detailed and quantitative recording of symptoms and related these scores to RT-induced endoscopic and histopathologic changes. Prevalence and severity of specific toxicity symptoms were recorded before, during (weeks 2 and 6) and 2 and 8 weeks after RT in 96 patients undergoing external beam RT for localized prostate cancer. RTOG/EORTC acute toxicity and ad hoc total toxicity scores (TTS) were recorded. TTS scores were calculated by adding scores based on visual analog scale (VAS) grading of individual symptoms. Fifty of the patients also underwent sequential proctoscopy with mucosal biopsy. Individual symptoms increased, but differed in prevalence and intensity during and after RT. TTS increased during the entire treatment course in spite of normalizing histopathologic and endoscopic changes from week 2 onwards. Twenty-seven patients had no RTOG/EORTC toxicity, four had grade 3 and none had grade 4 toxicity. All patients with grade 0 had increased TTS. Thus, TTS appeared more sensitive than RTOG/EORTC scoring. The study demonstrates that multiple toxicity symptoms contribute to total toxicity in response to pelvic RT. TTS is a feasible and sensitive method for detecting and quantifying acute toxicity and unveils morbidity which remains hidden with the RTOG/EORTC score system. The development and timing of symptoms may give clues to pathogenesis, treatment, and prophylaxis.

  15. Dynamic MLC tracking of moving targets with a single kV imager for 3D conformal and IMRT treatments

    Energy Technology Data Exchange (ETDEWEB)

    Poulsen, Per R. (Dept. of Oncology, Aarhus Univ. Hospital (Denmark)), E-mail: perpolse@rm.dk; Cho, Byungchul; Sawant, Amit; Ruan, Dan; Keall, Paul J. (Dept. of Radiation Oncology, Stanford Univ., Stanford (United States))

    2010-10-15

    Background. Tumor motion during radiotherapy is a major challenge for accurate dose delivery, in particular for hypofractionation and dose painting. The motion may be compensated by dynamic multileaf collimator (DMLC) tracking. Previous work has demonstrated that a single kV imager can accurately localize moving targets for DMLC tracking during rotational delivery, however this method has not been investigated for the static gantry geometry used for conformal and IMRT treatments. In this study we investigate the accuracy of single kV-imager based DMLC tracking for static-gantry delivery. Material and methods. A 5-field treatment plan with circular field shape and 200 MU per field was delivered in 20 s per field to a moving phantom with an embedded gold marker. Fluoroscopic kV images were acquired at 5 Hz perpendicular to the treatment beam axis during a 120 deg pre-treatment gantry rotation, during treatment delivery, and during inter-field gantry rotations. The three-dimensional marker position was estimated from the kV images and used for MLC adaptation. Experiments included 12 thoracic/abdominal tumor trajectories and five prostate trajectories selected from databases with 160 and 548 trajectories, respectively. The tracking error was determined as the mismatch between the marker position and the MLC aperture center in portal images. Simulations extended the study to all trajectories in the databases and to treatments with prolonged duration of 60 s per field. Results. In the experiments, the mean root-mean-square (rms) tracking error was 0.9 mm (perpendicular to MLC) and 1.1 mm (parallel to MLC) for thoracic/abdominal tumor trajectories and 0.6 mm (perpendicular) and 0.5 mm (parallel) for prostate trajectories. Simulations of these experiments agreed to within 0.1 mm. Simulations of all trajectories in the databases resulted in mean rms tracking errors of 0.6 mm (perpendicular) and 0.9 mm (parallel) for thorax/abdomen tumors and 0.4 mm (perpendicular) and 0

  16. Measurement of the Radiation Dose Rates of Patients Receiving Treatment with I-131 Using Telescopic Radiation Survey Meter

    Directory of Open Access Journals (Sweden)

    Yehia Lahfi

    2016-03-01

    Full Text Available Introduction In order to discharge the patients receiving treatment with large radiation doses of 131I for thyroid cancer, it is necessary to measure and evaluate the external dose rates of these patients. The aim of the study was to assess a new method of external dose rate measurement, and to analyze the obtained results as a function of time. Materials and Methods In this study, a telescopic radiation survey meter was utilized to measure the external dose rates of a sample population of 192 patients receiving treatment with high-dose 131I at one, 24, and 48 hours after dose administration. Results The proposed technique could reduce the occupational radiation exposure of the physicist by a factor of 1/16. Moreover, the external dose rates of both genders rapidly decreased with time according to bi-exponential equations, which could be attributed to the additional factors associated with iodine excretion, as well as the physiology of the body in terms of 131I uptake. Conclusion According to the results of this study, telescopic radiation survey meter could be used to measure the external dose rates of patients receiving treatment with 131I. Furthermore, the average difference in the radiation exposure between female and male patients was calculated to be less than 17%.

  17. Workers’ Conformism

    Directory of Open Access Journals (Sweden)

    Nikolay Ivantchev

    2013-10-01

    Full Text Available Conformism was studied among 46 workers with different kinds of occupations by means of two modified scales measuring conformity by Santor, Messervey, and Kusumakar (2000 – scale for perceived peer pressure and scale for conformism in antisocial situations. The hypothesis of the study that workers’ conformism is expressed in a medium degree was confirmed partly. More than a half of the workers conform in a medium degree for taking risk, and for the use of alcohol and drugs, and for sexual relationships. More than a half of the respondents conform in a small degree for anti-social activities (like a theft. The workers were more inclined to conform for risk taking (10.9%, then – for the use of alcohol, drugs and for sexual relationships (8.7%, and in the lowest degree – for anti-social activities (6.5%. The workers who were inclined for the use of alcohol and drugs tended also to conform for anti-social activities.

  18. Low-Dose-Rate Californium-252 Neutron Intracavitary Afterloading Radiotherapy Combined With Conformal Radiotherapy for Treatment of Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Min [Department of Oncology, Armed Police Hospital of Hangzhou, Hangzhou, Zhejiang Province (China); Xu Hongde [Cancer Center, Armed Police Hospital of Hangzhou, Hangzhou, Zhejiang Province (China); Pan Songdan; Lin Shan; Yue Jianhua [Department of Oncology, Armed Police Hospital of Hangzhou, Hangzhou, Zhejiang Province (China); Liu Jianren, E-mail: liujianren0571@hotmail.com [Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province (China)

    2012-07-01

    Purpose: To study the efficacy of low-dose-rate californium-252 ({sup 252}Cf) neutron intracavitary afterloading radiotherapy (RT) combined with external pelvic RT for treatment of cervical cancer. Methods and Materials: The records of 96 patients treated for cervical cancer from 2006 to 2010 were retrospectively reviewed. For patients with tumors {<=}4 cm in diameter, external beam radiation was performed (1.8 Gy/day, five times/week) until the dose reached 20 Gy, and then {sup 252}Cf neutron intracavitary afterloading RT (once/week) was begun, and the frequency of external beam radiation was changed to four times/week. For patients with tumors >4 cm, {sup 252}Cf RT was performed one to two times before whole-pelvis external beam radiation. The tumor-eliminating dose was determined by using the depth limit of 5 mm below the mucosa as the reference point. In all patients, the total dose of the external beam radiation ranged from 46.8 to 50 Gy. For {sup 252}Cf RT, the dose delivered to point A was 6 Gy/fraction, once per week, for a total of seven times, and the total dose was 42 Gy. Results: The mean {+-} SD patient age was 54.7 {+-} 13.7 years. Six patients had disease assessed at stage IB, 13 patients had stage IIA, 49 patients had stage IIB, 3 patients had stage IIIA, 24 patients had stage IIIB, and 1 patient had stage IVA. All patients obtained complete tumor regression (CR). The mean {+-} SD time to CR was 23.5 {+-} 3.4 days. Vaginal bleeding was fully controlled in 80 patients within 1 to 8 days. The mean {+-} SD follow-up period was 27.6 {+-} 12.7 months (range, 6-48 months). Five patients died due to recurrence or metastasis. The 3-year survival and disease-free recurrence rates were 89.6% and 87.5 %, respectively. Nine patients experienced mild radiation proctitis, and 4 patients developed radiocystitis. Conclusions: Low-dose-rate {sup 252}Cf neutron RT combined with external pelvic RT is effective for treating cervical cancer, with a low incidence of

  19. Breast cancer regional radiation fields for supraclavicular and axillary lymph node treatment: is a posterior axillary boost field technique optimal?

    Science.gov (United States)

    Wang, Xiaochun; Yu, Tse Kuan; Salehpour, Mohammad; Zhang, Sean X; Sun, Tzouh Liang; Buchholz, Thomas A

    2009-05-01

    To assess whether using an anterior oblique supraclavicular (SCV) field with a posterior axillary boost (PAB) field is an optimal technique for targeting axillary (AX) lymph nodes compared with two computed tomography (CT)-based techniques: (1) an SCV field with an anterior boost field and (2) intensity-modulated radiotherapy (IMRT). Ten patients with CT simulation data treated with postmastectomy radiation that included an SCV field were selected for the study. Supraclavicular nodes and AX Level I-III nodes within the SCV field were contoured and defined as the treatment target. Plans using the three techniques were generated and evaluated for each patient. The anterior axillary boost field and IMRT resulted in superior dose coverage compared with PAB. Namely, treatment volumes that received 105%, 80%, and 30% of prescribed dose for IMRT plans were significantly less than those for the anterior axillary boost plans, which were significantly less than PAB. For PAB and anterior axillary boost plans, there was a linear correlation between treatment volume receiving 105% of prescribed dose and maximum target depth. Furthermore, the IMRT technique resulted in better lung sparing and dose conformity to the target than anterior axillary boost, which again was significantly better than PAB. The maximum cord dose for IMRT was small, but higher than for the other two techniques. More monitor units were required to deliver the IMRT plan than the PAB plan, which was more than the anterior axillary boost plan. The PAB technique is not optimal for treatment of AX lymph nodes in an SCV field. We conclude that CT treatment planning with dose optimization around delineated target volumes should become standard for radiation treatments of supraclavicular and AX lymph nodes.

  20. Differential responses of tumors and normal brain to the combined treatment of 2-DG and radiation in glioablastoma.

    Science.gov (United States)

    Prasanna, Venkatesh K; Venkataramana, Neelam K; Dwarakanath, B S; Santhosh, Vani

    2009-09-01

    2-Deoxy-D-glucose (2-DG), an inhibitor of glucose transport and glycolysis, enhances radiation damage selectively in tumor cells by modulating damage response pathways resulting in cell death in vitro and local tumor control. Phase I and II clinical trials in patients with malignant glioma have shown excellent tolerance to a combined treatment of orally administered 2-DG and hypofractionated radiotherapy without any acute toxicity and late radiation damage. Phase III efficacy trials are currently at an advanced stage. Re-exploratory surgery performed in 13 patients due to persistent symptoms of elevated ICP and mass effect at different follow-up periods revealed extensive tumor necrosis with well-preserved normal brain tissue adjoining the tumor included in the treatment volume as revealed by a histological examination. These observations are perhaps the first clinical evidences for differential effects of 2-DG on tumors and normal tissues in conformity with earlier in vitro and in vivo studies in normal and tumor-bearing mice.

  1. The New Nitinol Conformable Self-Expandable Metal Stents for Malignant Colonic Obstruction: A Pilot Experience as Bridge to Surgery Treatment

    Directory of Open Access Journals (Sweden)

    Roberto Di Mitri

    2014-01-01

    Full Text Available Introduction. Self-expandable metal stents (SEMS are a nonsurgical option for treatment of malignant colorectal obstruction also as a bridge to surgery approach. The new nitinol conformable stent has improved clinical outcomes in these kinds of patients. We report a pilot experience with nitinol conformable SEMS placement as bridge to surgery treatment in patients with colorectal obstruction. Materials and Methods. Between April and August 2012, we collected data on colonic nitinol conformable SEMS placement in a cohort of consecutive symptomatic patients, with malignant colorectal obstruction, who were treated as a bridge to surgery. Technical success, clinical success, and adverse events were recorded. Results. Ten patients (7 male (70%, with a mean age of 69.2 ± 10.1, were evaluated. The mean length of the stenosis was 3.6 ± 0.6 cm. Five patients (50% were treated on an emergency basis. The median time from stent placement to surgery was 16 days (interquartile range 7–21. Technical and clinical success was achieved in all patients with a significant early improvement of symptoms. No adverse events due to the SEMS placement were observed. Conclusion. This pilot study confirmed the important role of nitinol conformable SEMS as a bridge to surgery option in the treatment of symptomatic malignant colorectal obstruction.

  2. Evaluation of bolus electron conformal therapy compared with conventional techniques for the treatment of left chest wall postmastectomy in patients with breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Opp, Dan, E-mail: Daniel.Opp@moffitt.org; Forster, Kenneth; Li, Weiqi; Zhang, Geoffrey; Harris, Eleanor E.

    2013-01-01

    Postmastectomy radiation (PMRT) lowers local-regional recurrence risk and improves survival in selected patients with breast cancer. The chest wall and lower axilla are technically challenging areas to treat with homogenous doses and normal tissue sparing. This study compares several techniques for PMRT to provide data to guide selection of optimal treatment techniques. Twenty-five consecutive left-sided patients treated postmastectomy were contoured using Radiation Therapy Oncology Group (RTOG) atlas guidelines then planned using 4 different PMRT techniques: opposed tangents with wedges (3-dimensional [3D] wedges), opposed tangents with field-in-field (FiF) modulation, 8-field intensity modulation radiotherapy (IMRT), and custom bolus electron conformal therapy (BolusECT, .decimal, Inc., Sanford, FL). Required planning target volume (PTV) coverage was held constant, and then dose homogeneity and normal tissue dose parameters were compared among the 4 techniques. BolusECT achieved clincally acceptable PTV coverage for 22 out of 25 cases. Compared with either tangential technique, IMRT and BolusECT provided the lowest heart V{sub 25} doses (3.3% ± 0.9% and 6.6% ± 3.2%, respectively with p < 0.0001). FiF had the lowest mean total lung dose (7.3 ± 1.1 Gy, with p = 0.0013), IMRT had the lowest total lung V{sub 20} (10.3% ± 1.6%, p < 0.0001), and BolusECT had the lowest mean heart dose (7.3 ± 2.0 Gy, p = 0.0002). IMRT provided the optimal dose homogeneity and normal tissue sparing compared with all other techniques for the cases in which BolusECT could not achieve acceptable PTV coverage. IMRT generally exposes contralateral breast and lung to slightly higher doses. Optimal PMRT technique depends upon patient anatomy. Patients whose maximal target volume depth is about 5.7 cm or less can be treated with BolusECT-assisted 12 or 15 MeV electron beams. At these energies, BolusECT has comparable dose-volume statistics as IMRT and lower heart V{sub 25} than opposed

  3. A semi-classical treatment of channeling radiation reaction

    Science.gov (United States)

    Huang, Zhirong; Chen, Pisin; Ruth, Ronald D.

    1996-10-01

    A semi-classical formalism is used to calculate the radiation reaction of a relativistic particle in a straight, continuous focusing system. Due to the absence of quantum excitation in such a focusing system, the radiation damping rate of the transverse action obtained using this formalism agrees exactly with the result from the classical Lorentz-Dirac radiation reaction equation. In the limit where the pitch angle of the particle is much smaller than the radiation opening angle, the transverse action damps exponentially with an energy-independent rate that is much faster than the energy decay rate. In the opposite limit, both the transverse action and the energy damp with power laws and their relative rates are comparable. The general time-dependence of the transverse action damping and the energy decay are obtained analytically from these rate equations.

  4. Argon plasma coagulation for treatment of hemorrhagic radiation gastroduodenitis

    Energy Technology Data Exchange (ETDEWEB)

    Maekawa, Shu-Ji; Aoyama, Nobuo; Shirasaka, Daisuke; Inoue, Takashi; Kuroda, Kohei; Ebara, Shigeyuki; Tamura, Takao; Miyamoto, Masaki; Kasuga, Masato [Kobe Univ. (Japan). Graduate School of Medicine

    2002-01-01

    A 79-year-old man who had received radiotherapy for portal vein thrombosis due to hepatocellular carcinoma (HCC) 5 months earlier, showed progressive anemia and melena. Endoscopy on admission revealed diffuse bleeding from multiple telangiectasias on the anterior wall of the antrum and bulbus. We treated this patient with a new non-contact hemostatic method: the argon plasma coagulator (APC). The melena stopped after the first session and the hemoglobin level remained stable for 7 months. No delayed complications have been observed. Gastrointestinal bleeding from chronic radiation gastroduodenitis is rarely reported compared with radiation proctitis. This case demonstrates that APC is effective for hemostasis of diffuse bleeding from radiation gastroduodenitis, just as for radiation protitis. (author)

  5. Malignant mesothelioma after radiation treatment for Hodgkin lymphoma

    DEFF Research Database (Denmark)

    De Bruin, Marie L; Burgers, Jacobus A; Baas, Paul

    2009-01-01

    Malignant mesothelioma is a relatively uncommon malignancy. Although the pathogenesis is primarily related to asbestos, the disease may be associated with radiation exposure. Recently, increased risks for second primary mesothelioma after radiation for lymphoma have been reported. Because...... and survival of the mesothelioma cases were comparable with cases from the general population, asbestos exposure and the proportion of males were lower than expected. The evidence for radiotherapy as cause for mesothelioma independent of exposure to asbestos is expanding, and the diagnosis of mesothelioma...

  6. 3D-conformal radiation therapy in prostate cancer. Technical considerations after 5 years of experience and 334 patients treated at the Istituto Europeo di Oncologia of Milan, Italy.

    Science.gov (United States)

    Ghilezan, M; Ivaldi, G; Cattani, F; Greco, C; Castiglioni, S; Leonardi, M C; Tosi, G; Marsiglia, H; Orecchia, R

    2001-01-01

    To report the technique of 3D-conformal radiation therapy (3D-CRT) currently used at our Institute for the treatment of prostate cancer with a curative intent. A critical review of the technical aspects of the technique is provided. Between December 1995 and October 2000, 334 patients with biopsy-proven adenocarcinoma of the prostate were treated with 3D-CRT. All patients were treated in a prone position with 15 MV X-ray beams and a 6-field technique for all but 20 patients, who were treated with a 3-field technique. Patients were simulated with the rectum and bladder empty. To ensure reproducible positioning, custom-made polyurethane foam or thermoplastic casts were produced for each patient. Subsequently, consecutive CT scan slices were obtained. The clinical target volume and critical organs (rectum and bladder) were identified on each CT slice. The beam's eye view technique was used to spatially display these structures, and the treatment portals were manually shaped based on the images obtained. The beam apertures were initially realized by conventional Cerrobend blocks (48 patients), which were replaced in October 1997 by a computer-driven multi-leaf collimator. The total target dose prescribed at the ICRU point is 76 Gy, delivered in 38 fractions and 54 days. The seminal vesicles are excluded at 70 Gy. Dose-volume histograms were obtained for all patients. If more than 30% of the bladder and/or more than 20% of the rectum receive >95% of the prescribed total dose, the treatment plan is judged as unsatisfactory and is adjusted. The dose-volume histogram can be improved by changing the beam's arrangement and/or weights or by introducing or modifying the wedge filters. 3D-CRT in prostate cancer patients is a highly sophisticated and time-consuming method of dose delivery. Important technical issues remain to be clarified.

  7. Multibeam tomotherapy: a new treatment unit devised for multileaf collimation, intensity-modulated radiation therapy.

    Science.gov (United States)

    Achterberg, Nils; Müller, Reinhold G

    2007-10-01

    A fully integrated system for treatment planning, application, and verification for automated multileaf collimator (MLC) based, intensity-modulated, image-guided, and adaptive radiation therapy (IMRT, IGRT and ART, respectively) is proposed. Patient comfort, which was the major development goal, will be achieved through a new unit design and short treatment times. Our device for photon beam therapy will consist of a new dual energy linac with five fixed treatment heads positioned evenly along one plane but one electron beam generator only. A minimum of moving parts increases technical reliability and reduces motion times to a minimum. Motion is allowed solely for the MLCs, the robotic patient table, and the small angle gantry rotation of +/- 36 degrees. Besides sophisticated electron beam guidance, this compact setup can be built using existing modules. The flattening-filter-free treatment heads are characterized by reduced beam-on time and contain apertures restricted in one dimension to the area of maximum primary fluence output. In the case of longer targets, this leads to a topographic intensity modulation, thanks to the combination of "step and shoot" MLC delivery and discrete patient couch motion. Owing to the limited number of beam directions, this multislice cone beam serial tomotherapy is referred to as "multibeam tomotherapy." Every patient slice is irradiated by one treatment head at any given moment but for one subfield only. The electron beam is then guided to the next head ready for delivery, while the other heads are preparing their leaves for the next segment. The "Multifocal MLC-positioning" algorithm was programmed to enable treatment planning and optimize treatment time. We developed an overlap strategy for the longitudinally adjacent fields of every beam direction, in doing so minimizing the field match problem and the effects of possible table step errors. Clinical case studies show for the same or better planning target volume coverage, better

  8. Radiation Therapy

    Science.gov (United States)

    ... the area is stitched shut. Another treatment, called proton-beam radiation therapy , focuses the radiation on the ... after radiation treatment ends. Sore mouth and tooth decay. If you received radiation therapy to the head ...

  9. Bevacizumab for the Treatment of Gammaknife Radiosurgery-Induced Brain Radiation Necrosis.

    Science.gov (United States)

    Ma, Yifang; Zheng, Chutian; Feng, Yiping; Xu, Qingsheng

    2017-09-01

    Radiation necrosis is one of the complications of Gammaknife radiosurgery. The traditional treatment of radiation necrosis carries a high risk of failure, Bevacizumab is an antiangiogenic monoclonal antibody against vascular endothelial growth factor, a known mediator of cerebral edema. It can be used to successfully treat brain radiation necrosis. Two patients with a history of small cell lung cancer presented with metastatic disease to the brain. They underwent Gammaknife radiosurgery to brain metastases. Several months later, magnetic resonance imaging showed radiation necrosis with significant surrounding edema. The patients had a poor response to treatment with dexamethasone. They were eventually treated with bevacizumab (5 mg/kg every 2 weeks, 7.5 mg/kg every 3 weeks, respectively), and the treatment resulted in significant clinical and radiographic improvement. Bevacizumab can be successfully used to treat radiation necrosis induced by Gammaknife radiosurgery in patients with cerebral metastases. It is of particular benefit in patients with poor reaction to corticosteroids and other medications.

  10. Hypo-fractionated radiation, magnetic nanoparticle hyperthermia and a viral immunotherapy treatment of spontaneous canine cancer

    Science.gov (United States)

    Hoopes, P. Jack; Moodie, Karen L.; Petryk, Alicia A.; Petryk, James D.; Sechrist, Shawntel; Gladstone, David J.; Steinmetz, Nicole F.; Veliz, Frank A.; Bursey, Alicea A.; Wagner, Robert J.; Rajan, Ashish; Dugat, Danielle; Crary-Burney, Margaret; Fiering, Steven N.

    2017-02-01

    It has recently been shown that cancer treatments such as radiation and hyperthermia, which have conventionally been viewed to have modest immune based anti-cancer effects, may, if used appropriately stimulate a significant and potentially effective local and systemic anti-cancer immune effect (abscopal effect) and improved prognosis. Using eight spontaneous canine cancers (2 oral melanoma, 3 oral amelioblastomas and 1 carcinomas), we have shown that hypofractionated radiation (6 x 6 Gy) and/or magnetic nanoparticle hyperthermia (2 X 43°C / 45 minutes) and/or an immunogenic virus-like nanoparticle (VLP, 2 x 200 μg) are capable of delivering a highly effective cancer treatment that includes an immunogenic component. Two tumors received all three therapeutic modalities, one tumor received radiation and hyperthermia, two tumors received radiation and VLP, and three tumors received only mNP hyperthermia. The treatment regimen is conducted over a 14-day period. All patients tolerated the treatments without complication and have had local and distant tumor responses that significantly exceed responses observed following conventional therapy (surgery and/or radiation). The results suggest that both hypofractionated radiation and hyperthermia have effective immune responses that are enhanced by the intratumoral VLP treatment. Molecular data from these tumors suggest Heat Shock Protein (HSP) 70/90, calreticulin and CD47 are targets that can be exploited to enhance the local and systemic (abscopal effect) immune potential of radiation and hyperthermia cancer treatment.

  11. General Conformity

    Science.gov (United States)

    The General Conformity requirements ensure that the actions taken by federal agencies in nonattainment and maintenance areas do not interfere with a state’s plans to meet national standards for air quality.

  12. Radiation protection in brachytherapic treatment of prostatic carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Mannino, G.; Bona, R.; Occhipinti, A. [Catania Univ. Hospital, ' Vittorio Emanuele, Ferrarotto e Santo Bambino' (Italy); Testagrossa, B.; Vermiglio, G.; Tripepi, M.G. [Messina Univ., Dept. of Protezionistica Ambientale, Sanitaria, Sociale ed Industriale (Italy)

    2006-07-01

    Purpose: To evaluate absorbed doses for medical staff and general public deriving from prostate brachytherapy with I-125 seeds. Methods And Materials: Radiation exposure measurements were made for staff and on a subset of 64 patients of the 100 trans perineal I-125 implanted seeds implants at the Vittorio Emanuele, Ferrarotto e Santo Bambino Universitary Hospital. Results: Absorbed doses for operators are very low when using radiation safety devices. The exposure rate at the anterior skin surface due to I-125 implanted seeds ranged from 32 to 120 {mu}Sv/hour. Conclusions: The evaluation of dose measurements shows that radiation risk associated to this practice is very low, both for staff that for critical group of population, if they follow the specific radioprotection statements supplied by health physicists. (authors)

  13. Radiation processing applications in the Czechoslovak water treatment technologies

    Science.gov (United States)

    Vacek, K.; Pastuszek, F.; Sedláček, M.

    The regeneration of biologically clogged water wells by radiation proved to be a successful and economically beneficial process among other promising applications of ionizing radiation in the water supply technology. The application conditions and experience are mentioned. The potential pathogenic Mycobacteria occuring in the warm washing and bathing water are resistant against usual chlorine and ozone concentrations. The radiation sensitivity of Mycobacteria allowed to suggest a device for their destroying by radiation. Some toxic substances in the underground water can be efficiently degraded by gamma radiation directly in the wells drilled as a hydraulic barrier surrounding the contaminated land area. Substantial decrease of CN - concentration and C.O.D. value was observed in water pumped from such well equipped with cobalt sources and charcoal. The removing of pathogenic contamination remains to be the main goal of radiation processing in the water purification technologies. The decrease of liquid sludge specific filter resistance and sedimentation acceleration by irradiation have a minor technological importance. The hygienization of sludge cake from the mechanical belt filter press by electron beam appears to be the optimum application in the Czechoslovak conditions. The potatoes and barley crop yields from experimental plots treated with sludge were higher in comparison with using the manure. Biological sludge from the municipal and food industry water purification plants contains nutritive components. The proper hygienization is a necessary condition for using them as a livestock feed supplement. Feeding experiments with broilers and pigs confirmed the possibility of partial (e.g. 50%) replacement of soya-, bone- or fish flour in feed mixtures by dried sludge hygienized either by heat or by the irradiation.

  14. Sequential induction chemotherapy followed by radical chemo-radiation in the treatment of locoregionally advanced head-and-neck cancer.

    Science.gov (United States)

    Bhide, S A; Ahmed, M; Barbachano, Y; Newbold, K; Harrington, K J; Nutting, C M

    2008-07-08

    We describe a retrospective series of patients with advanced head-and-neck cancer who were treated with induction chemotherapy followed by radical chemo-radiation. Patients treated with two cycles of induction chemotherapy followed by definitive chemo-radiation for squamous cell carcinoma of the head-and-neck region, from 2001 - 2006 at the Royal Marsden Hospital, formed the basis of this study. Cisplatin (75 mg m(-2)) on day 1 and 5-FU (1000 mg m(-2)) day 1 - 4 was the standard regimen used for induction treatment. Cisplatin (100 mg m(-2)) on day 1 and day 29 was used for concomitant treatment. The radiation was delivered using conformal technique. Tissues containing macroscopic and microscopic disease were treated to doses of 65 Gray (Gy) in 30 fractions and 50 Gy in 25 fractions, respectively. Data on patterns of relapse and acute toxicity (NCICTCv.3.0) were collected. A total of 129 patients were included, median age was 58 (range: 27 - 78). The site of tumour was: oropharynx 70 (54%), larynx 30 (23%), hypopharynx 24 (19%) and other 5 (4%). The median follow-up was 19 months (range: 4 - 58). Local control, disease-specific survival and overall survival at 2 years were 71%, 68% and 63%, respectively. The distant recurrence rate at 2 years was 9%. Ten patients required dose reduction during induction chemotherapy due to toxicity. The dose of 5-FU was reduced in six patients and that of cisplatin in four patients. The incidence of grade 3/4 toxicity was: neutropenia 5%, thrombocytopenia 1%, nausea and vomiting 3%. One cycle of concurrent cisplatin was omitted in 23 patients due to toxicity. Full-dose radiotherapy was administered to 98% of patients. The incidence of grade 3/4 toxicity was: skin 20%, dysphagia 65%, mucositis 60%, neutropenia 3%, anaemia 1%, nausea and vomiting 4%, nephrotoxicity 1%. Induction chemotherapy followed by radical chemo-radiation is a safe and tolerable regimen in the treatment of advanced head-and-neck cancer. Distant recurrence rates

  15. Ceiling art in a radiation therapy department: its effect on patient treatment experience

    Energy Technology Data Exchange (ETDEWEB)

    Bonett, Jotham [Sunshine Hospital Radiation Therapy Centre, Melbourne, Vic. (Australia)

    2015-09-15

    A new initiative has been implemented at the Sunshine Hospital Radiation Therapy Centre, to provide a calming and comforting environment for patients attending radiation therapy treatment. As part of this initiative, the department's computed tomography (CT) room and radiation therapy bunkers were designed to incorporate ceiling art that replicates a number of different visual scenes. The study was undertaken to determine if ceiling art in the radiation therapy treatment CT and treatment bunkers had an effect on a patient's experience during treatment at the department. Additionally, the study aimed to identify which of the visuals in the ceiling art were most preferred by patients. Patients were requested to complete a 12-question survey. The survey solicited a patient's opinion/perception on the unit's unique ceiling display with emphasis on aesthetic appeal, patient treatment experience and the patient's engagement due to the ceiling display. The responses were dichotomised to ‘positive’ or ‘negative’. Every sixth patient who completed the survey was invited to have a general face-to-face discussion to provide further information about their thoughts on the displays. The results demonstrate that the ceiling artwork solicited a positive reaction in 89.8% of patients surveyed. This score indicates that ceiling artwork contributed positively to patients’ experiences during radiation therapy treatment. The study suggests that ceiling artwork in the department has a positive effect on patient experience during their radiation therapy treatment at the department.

  16. Mathematical Optimization Techniques for Multi-Phase Radiation Treatment Design

    OpenAIRE

    Sonderman, David

    1983-01-01

    A mathematical model for optimal external beam radiotherapy treatment design over multiple treatment phases is presented. The solution procedure is discussed and illustrated on a case of boost treatment for lung cancer. The models are integrated with current radiobiological software to produce an optimal design over both phases of treatment displayed by means of computer graphics.

  17. Inhibition of trihalomethane formation in city water by radiation-ozone treatment and rapid composting of radiation disinfected sewage sludge

    Science.gov (United States)

    Takehisa, M.; Arai, H.; Arai, M.; Miyata, T.; Sakumoto, A.; Hashimoto, S.; Nishimura, K.; Watanabe, H.; Kawakami, W.; Kuriyama, I.

    Humic acid and Fulvic acid in natural water are precursors of carcinogenic THM which is formed during chlorine disinfection in city water processing. The radiation-oxidation process in the presence of ozone is effective to remove the precursors. The THM formation was reduced more than the decrease in TOC by the combination treatment. This is mainly due to a change in the chemical structure of the oxidation products. A composting of radiation disinfected sludge cake for agricultural reuse could be achieved within 3 days primary fermentation in a sewage plant. The rapid fermentation with use of radiation is effective to scale down of a fermentor of composting plant and the process reduces a health risk from the workers as well as final users.

  18. A new on-board imaging treatment technique for palliative and emergency treatments in radiation oncology

    Energy Technology Data Exchange (ETDEWEB)

    Held, Mareike

    2016-03-23

    This dissertation focuses on the use of on-board imaging systems as the basis for treatment planning, presenting an additional application for on-board images. A clinical workflow is developed to simulate, plan, and deliver a simple radiation oncology treatment rapidly, using 3D patient scans. The work focuses on an on-line dose planning and delivery process based on on-board images entirely performed with the patient set up on the treatment couch of the linear accelerator. This potentially reduces the time between patient simulation and treatment to about 30 minutes. The basis for correct dose calculation is the accurate image gray scale to tissue density calibration. The gray scale, which is defined in CT Numbers, is dependent on the energy spectrum of the beam. Therefore, an understanding of the physics characteristics of each on-board system is required to evaluate the impact on image quality, especially regarding the underlying cause of image noise, contrast, and non-uniformity. Modern on-board imaging systems, including kV and megavoltage (MV) cone beam (CB) CT as well as MV CT, are characterized in terms of image quality and stability. A library of phantom and patient CT images is used to evaluate the dose calculation accuracy for the on-board images. The dose calculation objective is to stay within 5% local dose differences compared to standard kV CT dose planning. The objective is met in many treatment cases. However, dose calculation accuracy depends on the anatomical treatment site. While on-board CT-based treatments of the head and extremities are predictable within 5% on all systems, lung tissue and air cavities may create local dose discrepancies of more than 5%. The image quality varies between the tested units. Consequently, the CT number-to-density calibration is defined independently for each system. In case of some imaging systems, the CT numbers of the images are dependent on the protocol used for on-board imaging, which defines the imaging dose

  19. 21 CFR 179.39 - Ultraviolet radiation for the processing and treatment of food.

    Science.gov (United States)

    2010-04-01

    ... treatment of food. 179.39 Section 179.39 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH... processing and treatment of food. Ultraviolet radiation for the processing and treatment of food may be... products Without ozone production: high fat-content food irradiated in vacuum or in an inert...

  20. Intensity modulated radiation therapy for squamous cell carcinoma of the vulva: Treatment technique and outcomes

    Directory of Open Access Journals (Sweden)

    Yuan James Rao, MD

    2017-04-01

    Conclusions: IMRT for vulvar cancer is associated with high rates of LRC in the postoperative setting and limited radiation-related toxicity. Durable LRC of disease after definitive IMRT remains challenging, and several refinements to our treatment technique are suggested.

  1. Reducing Toxicity of Radiation Treatment of Advanced Prostate Cancer

    Science.gov (United States)

    2015-10-01

    408- mitigated mice showed lineage-balanced, long-term, multilineage potential as determined by serial bone marrow transplantation , indicative of...kappaB inhibitors alleviate and the proteasome inhibitor PS-341 exacerbates radiation toxicity in zebrafish embryos . Molecular Cancer Therapeutics 8

  2. Sucralfate versus mesalazine versus hydrocortisone in the prevention of acute radiation proctitis during conformal radiotherapy for prostate carcinoma. A randomized study

    Energy Technology Data Exchange (ETDEWEB)

    Sanguineti, G.; Franzone, P.; Marcenaro, M.; Vitale, V. [Dept. of Radiation Oncology, National Inst. for Cancer Research, Genova (Italy); Foppiano, F. [Dept. of Physics, National Inst. for Cancer Research, Genova (Italy)

    2003-07-01

    Purpose: To assess whether the topical use of steroids or 5-aminosalicylic acid (5-ASA) is superior to sucralfate in preventing acute rectal toxicity during three-dimensional conformal radiotherapy (3DCRT) to 76 Gy. Patients and Methods: Patients undergoing 3DCRT for prostate carcinoma at our institution were offered to be randomized to sucralfate 3 g in 15 ml suspension enema (Antepsin {sup trademark}), mesalazine 4 g gel enema (Enterasyn trademark), or hydrocortisone 100 mg foam enema (Colifoam {sup trademark}). Randomization was blind to the treating physician but not to the patient. Sucralfate was chosen as control arm. Topical treatment had to be performed once daily, starting on day 1 of 3DCRT. Acute rectal toxicity was scored weekly according to RTOG criteria. Time to occurrence of grade 2+ acute rectal toxicity was taken as endpoint. Results: The trial was opened in August 1999, and after the first 24 patients had been treated, arm 2 was discontinued because of eight patients receiving mesalazine, seven actually developed acute rectal toxicity (five patients grade 3 and two patients grade 2). Until May 2001, 134 consecutive patients were randomly assigned to sucralfate (63 patients), mesalazine (eight patients) or hydrocortisone (63 patients). The cumulative incidence of acute rectal toxicity at the end of treatment by arm is 61.9 {+-} 6.1%, 87.5 {+-} 11.7%, and 52.4 {+-} 6.2% for arms 1, 2, and 3, respectively. The difference between the mesalazine group and the sucralfate group is highly significant (hazard ratio [HR] 2.5, 95% confidence interval [CI] 1.1-5.7; p = 0.03). At both uni- and multivariate analysis taking into account several patients and treatment covariates, the difference between hydrocortisone and sucralfate is not significant (HR 0.7, 95% CI 0.5-1.2; p = 0.2). Conclusion: Topical mesalazine is contraindicated during radiotherapy. Hydrocortisone enema is not superior to sucralfate in preventing acute rectal toxicity. (orig.)

  3. Predictors of Psychosocial Adjustment During the Post-Radiation Treatment Transition

    OpenAIRE

    Mazanec, Susan; Daly, Barbara J.; Douglas, Sara; Musil, Carol

    2010-01-01

    The aim of this study was to examine the role of cognitive appraisal in predicting psychosocial adjustment during the post-radiation treatment transition. A predictive correlational design was used in a convenience sample of 80 patients with breast, lung, and prostate cancer who were receiving radiation therapy. Two weeks prior to completion of treatment, subjects completed instruments to measure symptom distress, uncertainty, cognitive appraisal, social support and self-efficacy for coping. ...

  4. New Technologies in Radiation Oncology

    Science.gov (United States)

    Schlegel, Wolfgang; Bortfeld, Thomas; Grosu, Anca-Ligia

    This book provides an overview of recent advances in radiation oncology, many of which have originated from physics and engineering sciences. After an introductory section on basic aspects of 3D medical imaging, the role of 3D imaging in the context of radiotherapy is explored in a series of chapters on the various modern imaging techniques. A further major section addresses 3D treatment planning for conformal radiotherapy, with consideration of both external radiotherapy and brachytherapy. Subsequently the modern techniques of 3D conformal radiotherapy are described, including stereotactic radiotherapy, intensity-modulated radiation therapy, image-guided and adaptive radiotherapy, and radiotherapy with charged particles.

  5. [Dosimetric evaluation of conformal radiotherapy: conformity factor].

    Science.gov (United States)

    Oozeer, R; Chauvet, B; Garcia, R; Berger, C; Felix-Faure, C; Reboul, F

    2000-01-01

    The aim of three-dimensional conformal therapy (3DCRT) is to treat the Planning Target Volume (PTV) to the prescribed dose while reducing doses to normal tissues and critical structures, in order to increase local control and reduce toxicity. The evaluation tools used for optimizing treatment techniques are three-dimensional visualization of dose distributions, dose-volume histograms, tumor control probabilities (TCP) and normal tissue complication probabilities (NTCP). These tools, however, do not fully quantify the conformity of dose distributions to the PTV. Specific tools were introduced to measure this conformity for a given dose level. We have extended those definitions to different dose levels, using a conformity index (CI). CI is based on the relative volumes of PTV and outside the PTV receiving more than a given dose. This parameter has been evaluated by a clinical study including 82 patients treated for lung cancer and 82 patients treated for prostate cancer. The CI was low for lung dosimetric studies (0.35 at the prescribed dose 66 Gy) due to build-up around the GTV and to spinal cord sparing. For prostate dosimetric studies, the CI was higher (0.57 at the prescribed dose 70 Gy). The CI has been used to compare treatment plans for lung 3DCRT (2 vs 3 beams) and prostate 3DCRT (4 vs 7 beams). The variation of CI with dose can be used to optimize dose prescription.

  6. The Importance of the Conformality, Heterogeneity, and Gradient Indices in Evaluating Gamma Knife Radiosurgery Treatment Plans for Intracranial Meningiomas

    Energy Technology Data Exchange (ETDEWEB)

    Balagamwala, Ehsan H. [Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH (United States); Suh, John H. [Department of Radiation Oncology, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Barnett, Gene H. [Department of Neurosurgery, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Khan, Mohammad K. [Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA (United States); Neyman, Gennady [Department of Radiation Oncology, Cleveland Clinic, Cleveland, OH (United States); Cai, Rong S. [Children' s Medical Center, Dallas, TX (United States); Vogelbaum, Michael A. [Department of Neurosurgery, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Novak, Eric [Department of Quantitative Health Sciences Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States); Chao, Samuel T., E-mail: chaos@ccf.org [Department of Radiation Oncology, Rosa Ella Burkhardt Brain Tumor and Neuro-oncology Center, Taussig Cancer Institute, Cleveland Clinic, Cleveland, OH (United States)

    2012-08-01

    Purpose: To investigate the relationship between the conformality index (CIn), heterogeneity index (HIn), and gradient index (GIn) and the development of toxicity in patients treated with Gamma Knife radiosurgery (GKRS) for intracranial meningiomas. Methods and Materials: Treatment records of patients treated from 1997 to 2009 with at least 6 months of follow-up were reviewed. The following parameters were collected: CIn, HIn, GIn (ratio of the volume receiving half the prescription isodose to the volume receiving the full prescription isodose), brainstem (BS) maximum dose (MD), BS volume receiving {>=}12 Gy (V12), optic apparatus (OA) MD, OA V8 Gy, OA V10, number of isocenters, number of isocenters outside target volume, and the occurrence of six toxicities. Univariate and multivariate logistic regression modeling were used for analysis. Results: This study included 145 patients (148 meningiomas) with a median follow-up time of 27 months (range, 6-113.9 months). The majority of meningiomas were located in the skull base (53%). The median prescription dose was 13 Gy (range, 10-24 Gy) to the 51.50% (range, 50-92%) isodose. A lower HIn was correlated with a higher GIn (p = 0.007). CIn was not associated with any toxicity. Higher HIn was associated with the development of dizziness (odds ratio [OR] 1.9; p = 0.02), whereas a lower GIn was associated with motor deficits (OR 0.38; p = 0.04) and auditory changes (OR 0.59; p = 0.04). The OA MD, V8, and V12 were not associated with visual changes, but visual changes were associated with a higher number of isocenters outside the target volume (OR 1.93; p = 0.07). BS V12 was correlated with the development of auditory changes (OR 1.05; p = 0.05), whereas patients with higher BS MD tended to have increased toxicity. Conclusions: Close attention must be paid to all three indices (CIn, HIn, GIn) when optimal treatment plans are determined. We recommend that the target CIn should be {<=}2.0, the HIn {<=}2.0, and the GIn {>=}3

  7. Granulocyte Colony-Stimulating Factor in the Treatment of Acute Radiation Syndrome: A Concise Review

    Directory of Open Access Journals (Sweden)

    Michal Hofer

    2014-04-01

    Full Text Available This article concisely summarizes data on the action of one of the principal and best known growth factors, the granulocyte colony-stimulating factor (G-CSF, in a mammalian organism exposed to radiation doses inducing acute radiation syndrome. Highlighted are the topics of its real or anticipated use in radiation accident victims, the timing of its administration, the possibilities of combining G-CSF with other drugs, the ability of other agents to stimulate endogenous G-CSF production, as well as of the capability of this growth factor to ameliorate not only the bone marrow radiation syndrome but also the gastrointestinal radiation syndrome. G-CSF is one of the pivotal drugs in the treatment of radiation accident victims and its employment in this indication can be expected to remain or even grow in the future.

  8. Treatment and prevention of acute radiation dermatitis;Traitement et prevention des radiodermites aigues

    Energy Technology Data Exchange (ETDEWEB)

    Benomar, S.; Hassam, B. [Service de dermatologie, CHU Ibn-Sina, universite Mohamed-V, Rabat (Morocco); Boutayeb, S.; Errihani, H. [Service de d' oncologie medicale, Institut national d' oncologie, Universite Mohamed-V, Rabat (Morocco); Lalya, I.; El Gueddari, B.K. [Service de radiotherapie, Institut national d' oncologie, universite Mohamed-V, Rabat (Morocco)

    2010-06-15

    Acute radiation dermatitis is a common side-effect of radiotherapy which often necessitates interruption of the therapy. Currently, there is no general consensus about its prevention or about the treatment of choice. The goal of this work was to focus on optimal methods to prevent and manage acute skin reactions related to radiation therapy and to determine if there are specific topical or oral agents for the prevention of this acute skin reaction. The prevention and the early treatment are the two focus points of the management of the acute radiation dermatitis. (authors)

  9. Experience of laser radiation for treatment of oral mucous lesions of different etiologies

    Science.gov (United States)

    Mosesyants, Elvira N.; Zazulevskaya, Lidiya Y.; Shevtsova, Elena

    1997-05-01

    Laser irradiation use for treatment of different manifestations of oral mucous diseases during the last 10 years. The aim of this research was study of the results of use He-Ne laser radiation in combination with main therapy for treatment of oral mucous lesions of different aetiology. He-Ne laser irradiation use for radiation of lesions were caused by different aetiology reasons. Under the observation was 116 patients 20 - 64 years old, who had and hadn't background pathology. There were biochemical, immunological controls. Data of research confirmed positive effect of use He-Ne laser radiation.

  10. Effect of high-energy radiation and alkali treatment on the properties of cellulose

    Energy Technology Data Exchange (ETDEWEB)

    Foeldvary, Cs.M. E-mail: foldvary@iki.kfki.hu; Takacs, E.; Wojnarovits, L

    2003-06-01

    The effect of the treatment with NaOH or tetramethyl ammonium hydroxide solutions on preirradiated cotton-cellulose was investigated. Both the radiation and the treatment with alkali solutions caused loss of weight in cellulose; however, there was a synergism, a high weight loss was observed during alkali treatment of preirradiated samples. The radiation caused scissions of the cellulose chains and during the treatment with aqueous alkaline solutions some smaller fragments dissolved, resulting in a strong absorbance of the solutions with maximum at around 268 nm. It was attributed to the absorbance of aldehyde/keto groups.

  11. Radiofrequency ablation versus surgical resection for the treatment of hepatocellular carcinoma conforming to the Milan criteria: systemic review and meta-analysis.

    Science.gov (United States)

    Yi, Hui-Ming; Zhang, Wei; Ai, Xi; Li, Kai-Yan; Deng, You-Bin

    2014-01-01

    Radiofrequency ablation (RFA) is a promising ablation technique and has become one of the best alternatives for hepatocellular carcinoma (HCC) patients. But whether RFA or surgical resection (SR) is the better treatment for HCC conforming to the Milan criteria has long been debated. A meta-analysis of trials that compared RFA versus SR was conducted regarding the survival rate and recurrence rate. Pooled odds ratios (OR) with 95% confidence intervals (95% CI) were calculated using fixed or random effects models. Nineteen studies, comprising 2 randomized controlled trials and 17 non-randomized controlled trials, were included with a total of 2895 patients. The 5 years overall survival rate for SR group was significantly higher than that for RFA group. In the SR group, the local recurrence rate was significantly lower when compared with the RFA group. This meta-analysis yielded no significant differences between laparoscopic RFA and SR in 5-year overall survival rate. In conclusion, surgical resection remains the better choice of treatment for HCC conforming to the Milan criteria, whereas RFA should be considered as an effective alternative treatment when surgery is not feasible. As for RFA technique, laparoscopic approach may be more effective than percutaneous approach for HCC conforming to Milan criteria.

  12. Proton Beam Therapy Versus Conformal Photon Radiation Therapy for Childhood Craniopharyngioma: Multi-institutional Analysis of Outcomes, Cyst Dynamics, and Toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Bishop, Andrew J. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Greenfield, Brad [Department of Radiation Oncology, Baylor College of Medicine, Houston, Texas (United States); Mahajan, Anita [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Paulino, Arnold C. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Department of Radiation Oncology, Baylor College of Medicine, Houston, Texas (United States); Okcu, M. Fatih [Department of Pediatrics, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Chintagumpala, Murali [Department of Pediatrics, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); Kahalley, Lisa S. [Section of Psychology, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); McAleer, Mary F.; McGovern, Susan L. [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States); Whitehead, William E. [Department of Neurosurgery, Texas Children' s Cancer and Hematology Center, Baylor College of Medicine, Houston, Texas (United States); Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston, Texas (United States)

    2014-10-01

    Purpose: We compared proton beam therapy (PBT) with intensity modulated radiation therapy (IMRT) for pediatric craniopharyngioma in terms of disease control, cyst dynamics, and toxicity. Methods and Materials: We reviewed records from 52 children treated with PBT (n=21) or IMRT (n=31) at 2 institutions from 1996-2012. Endpoints were overall survival (OS), disease control, cyst dynamics, and toxicity. Results: At 59.6 months' median follow-up (PBT 33 mo vs IMRT 106 mo; P<.001), the 3-year outcomes were 96% for OS, 95% for nodular failure-free survival and 76% for cystic failure-free survival. Neither OS nor disease control differed between treatment groups (OS P=.742; nodular failure-free survival P=.546; cystic failure-free survival P=.994). During therapy, 40% of patients had cyst growth (20% requiring intervention); immediately after therapy, 17 patients (33%) had cyst growth (transient in 14), more commonly in the IMRT group (42% vs 19% PBT; P=.082); and 27% experienced late cyst growth (32% IMRT, 19% PBT; P=.353), with intervention required in 40%. Toxicity did not differ between groups. On multivariate analysis, cyst growth was related to visual and hypothalamic toxicity (P=.009 and .04, respectively). Patients given radiation as salvage therapy (for recurrence) rather than adjuvant therapy had higher rates of visual and endocrine (P=.017 and .024, respectively) dysfunction. Conclusions: Survival and disease-control outcomes were equivalent for PBT and IMRT. Cyst growth is common, unpredictable, and should be followed during and after therapy, because it contributes to late toxicity. Delaying radiation therapy until recurrence may result in worse visual and endocrine function.

  13. Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma; Hypofractionated radiation therapy for the treatment of feline facial squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Cunha, S.C.S.; Corgozinho, K.B.; Holguin, P.G.; Ferreira, A.M.R., E-mail: simonecsc@gmail.co [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Carvalho, L.A.V. [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Canary, P.C.; Reisner, M. [Hospital Universitario Clementino Fraga Filho (HUCFF/UFRJ), Rio de Janeiro, RJ (Brazil); Pereira, A.N.; Souza, H.J.M. [Universidade Federal Rural do Rio de Janeiro (UFRRJ), Seropedica, RJ (Brazil)

    2010-07-01

    The efficacy of hypofractionated radiation protocol for feline facial squamous cell carcinoma was evaluated. Hypofractionated radiation therapy was applied to five cats showing single or multiple facial squamous cell carcinomas, in a total of ten histologically confirmed neoplastic lesions. Of the lesions, two were staged as T{sub 1}, four as T{sub 2}, two as T{sub 3}, and two as T{sub 4}. The animals were submitted to four radiation fractions from 7.6 to 10 grays each, with one week intervals. The equipment was a linear accelerator with electrons beam. The cats were evaluated weekly during the treatment and 30 and 60 days after the end of the radiation therapy. In this study, 40% of the lesions had complete remission, 40% partial remission, and 20% did not respond to the treatment. Response rates were lower as compared to other protocols previously used. However, hypofractionated radiation protocol was considered safe for feline facial squamous cell carcinoma. (author)

  14. Long-Term Outcomes After High-Dose Postprostatectomy Salvage Radiation Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Goenka, Anuj; Magsanoc, Juan Martin; Pei Xin; Schechter, Michael; Kollmeier, Marisa; Cox, Brett [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Scardino, Peter T.; Eastham, James A. [Urology Service, Department of Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Zelefsky, Michael J., E-mail: zelefskm@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2012-09-01

    Purpose: To review the impact of high-dose radiotherapy (RT) in the postprostatectomy salvage setting on long-term biochemical control and distant metastases-free survival, and to identify clinical and pathologic predictors of outcomes. Methods and Materials: During 1988-2007, 285 consecutive patients were treated with salvage RT (SRT) after radical prostatectomy. All patients were treated with either three-dimensional conformal RT or intensity-modulated RT. Two hundred seventy patients (95%) were treated to a dose {>=}66 Gy, of whom 205 (72%) received doses {>=}70 Gy. Eighty-seven patients (31%) received androgen-deprivation therapy as a component of their salvage treatment. All clinical and pathologic records were reviewed to identify treatment risk factors and response. Results: The median follow-up time after SRT was 60 months. Seven-year actuarial prostate-specific antigen (PSA) relapse-free survival and distant metastases-free survival were 37% and 77%, respectively. Independent predictors of biochemical recurrence were vascular invasion (p < 0.01), negative surgical margins (p < 0.01), presalvage PSA level >0.4 ng/mL (p < 0.01), androgen-deprivation therapy (p = 0.03), Gleason score {>=}7 (p = 0.02), and seminal vesicle involvement (p = 0.05). Salvage RT dose {>=}70 Gy was not associated with improvement in biochemical control. A doubling time <3 months was the only independent predictor of metastatic disease (p < 0.01). There was a trend suggesting benefit of SRT dose {>=}70 Gy in preventing clinical local failure in patients with radiographically visible local disease at time of SRT (7 years: 90% vs. 79.1%, p = 0.07). Conclusion: Salvage RT provides effective long-term biochemical control and freedom from metastasis in selected patients presenting with detectable PSA after prostatectomy. Androgen-deprivation therapy was associated with improvement in biochemical progression-free survival. Clinical local failures were rare but occurred most commonly in

  15. The concept and evolution of involved site radiation therapy for lymphoma

    DEFF Research Database (Denmark)

    Specht, Lena; Yahalom, Joachim

    2015-01-01

    We describe the development of radiation therapy for lymphoma from extended field radiotherapy of the past to modern conformal treatment with involved site radiation therapy based on advanced imaging, three-dimensional treatment planning and advanced treatment delivery techniques. Today, radiatio...

  16. [Clinical evaluation of the effectiveness of radiation treatment for endometrial cancer].

    Science.gov (United States)

    Turkevich, V G

    2014-01-01

    The study is based on data on 306 patients with endometrial cancer treated as combined (remote + contact) and only the contact exposure with low, medium and high dose rate. For comparative radiobiological evaluation of reactions of irradiated tissues there were used the following radiobiological models: factor time-dose-fractionation, the cumulative radiation effect, linear- quadratic model in the variant of biologically effective dose. Survival of endometrial cancer patients undergone combined or only the contact radiation treatment was determined by the stage of disease. In particular, the survival of patients with Stage IB endometrial cancer (combined radiation treatment) was significantly higher than in Stage IC, while in Stage IB (contact radiation treatment) was significantly higher than in Stages IC and IIB. Long-term results of radiation treatment of patients with all Stages of endometrial cancer were significantly better by 16% when only the contact radiation treatment was performed. The most preferred component of radiotherapy in women suffering from endometrial cancer with severe comorbidities was brachytherapy with high dose rate both in the combined and only contact irradiation.

  17. Development of radiation biological dosimetry and treatment of radiation-induced damaged tissue

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Chul Koo; Kim, Tae Hwan; Lee, Yun Sil [and others

    2000-04-01

    Util now, only a few methods have been developed for radiation biological dosimetry such as conventional chromosome aberration and micronucleus in peripheral blood cell. However, because these methods not only can be estimated by the expert, but also have a little limitation due to need high technique and many times in the case of radiation accident, it is very difficult to evaluate the absorbed dose of victims. Therefore, we should develop effective, easy, simple and rapid biodosimetry and its guideline(triage) to be able to be treated the victims as fast as possible. We established the apoptotic fragment assay, PCC, comet assay, and micronucleus assay which was the significant relationship between dose and cell damages to evaluate the irradiated dose as correct and rapid as possible using lymphocytes and crypt cells, and compared with chromosome dosimetry and micronucleus assay.

  18. Effect of treatment modality on the hypothalamic-pituitary function of patients treated with radiation therapy for pituitary adenomas: Hypothalamic dose and endocrine outcomes.

    Directory of Open Access Journals (Sweden)

    Andrew eElson

    2014-04-01

    Full Text Available Background: Both fractionated external beam radiotherapy and single fraction radiosurgery for pituitary adenomas are associated with the risk of hypothalamic-pituitary (HP axis dysfunction.Objective: To analyze the effect of treatment modality (Linac, TomoTherapy, or Gamma Knife on hypothalamic dose and correlate these with HP-Axis deficits after radiotherapy.Methods:Radiation plans of patients treated postoperatively for pituitary adenomas using Linac-based 3D Conformal Radiotherapy (CRT (n=11, TomoTherapy-based Intensity Modulated Radiation Therapy (IMRT (n=10, or Gamma Knife Stereotactic Radiosurgery (SRS(n=12 were retrospectively reviewed. Dose to the hypothalamus was analyzed and postradiotherapy hormone function including growth hormone (GH, thyroid (TSH, adrenal (ACTH, prolactin (PRL, and gonadotropins (FSH/LH were assessed. Results:Post-radiation, 13 of 27 (48% patients eligible for analysis developed at least one new hormone deficit, of which 8 of 11 (72% occurred in the Linac group, 4 of 8 (50% occurred in the TomoTherapy group, and 1 of 8 (12.5% occurred in the Gamma Knife group. Compared with fractionated techniques, Gamma Knife showed improved hypothalamic sparing for DMax Hypo, and V12Gy. For fractionated modalities, TomoTherapy showed improved dosimetric characteristics over Linac-based treatment with hypothalamic DMean (44.8 Gy vs. 26.8 Gy p=0.02, DMax (49.8 Gy vs. 39.1 Gy p=0.04, and V12Gy (100% vs. 76% p=0.004.Conclusion:Maximal dosimetric avoidance of the hypothalamus was achieved using Gamma Knife-based radiosurgery followed by TomoTherapy-based IMRT, and Linac-based 3D conformal radiation therapy, respectively.

  19. Radiosurgical planning of meningiomas: compromises with conformity.

    Science.gov (United States)

    Rowe, Jeremy G; Walton, Lee; Vaughan, Paul; Malik, Irfan; Radatz, Matthias; Kemeny, Andras

    2004-01-01

    The radiosurgical planning of meningiomas frequently necessitates compromises between irradiating tumour and risking damage to adjacent structures. In selected cases, we resolved this by excluding part of the tumour from the prescription isodose volume. Most of these compromises or 'suboptimal' plans achieved growth control. Growth control could not be related to conformity indices or to various measures of the radiation dose received by the meningioma. Examining recurrences, 75% arose from dura outside the original treatment field. These findings are discussed in terms of dose prescription protocols and the use of conformity indices in planning. The importance of the dural origin of meningiomas is well established in surgical practice, as reflected by Simpson's grades, but may be equally significant in radiosurgical practice.

  20. IMRT and 3D conformal radiotherapy with or without elective nodal irradiation in locally advanced NSCLC. A direct comparison of PET-based treatment planning

    Energy Technology Data Exchange (ETDEWEB)

    Fleckenstein, Jochen; Kremp, Katharina; Kremp, Stephanie; Palm, Jan; Ruebe, Christian [Saarland University Medical School, Department of Radiotherapy and Radiation Oncology, Homburg/Saar (Germany)

    2016-02-15

    The potential of intensity-modulated radiation therapy (IMRT) as opposed to three-dimensional conformal radiotherapy (3D-CRT) is analyzed for two different concepts of fluorodeoxyglucose positron emission tomography (FDG PET)-based target volume delineation in locally advanced non-small cell lung cancer (LA-NSCLC): involved-field radiotherapy (IF-RT) vs. elective nodal irradiation (ENI). Treatment planning was performed for 41 patients with LA-NSCLC, using four different planning approaches (3D-CRT-IF, 3D-CRT-ENI, IMRT-IF, IMRT-ENI). ENI included a boost irradiation after 50 Gy. For each plan, maximum dose escalation was calculated based on prespecified normal tissue constraints. The maximum prescription dose (PD), tumor control probability (TCP), conformal indices (CI), and normal tissue complication probabilities (NTCP) were analyzed. IMRT resulted in statistically significant higher prescription doses for both target volume concepts as compared with 3D-CRT (ENI: 68.4 vs. 60.9 Gy, p < 0.001; IF: 74.3 vs. 70.1 Gy, p < 0.03). With IMRT-IF, a PD of at least 66 Gy was achieved for 95 % of all plans. For IF as compared with ENI, there was a considerable theoretical increase in TCP (IMRT: 27.3 vs. 17.7 %, p < 0.00001; 3D-CRT: 20.2 vs. 9.9 %, p < 0.00001). The esophageal NTCP showed a particularly good sparing with IMRT vs. 3D-CRT (ENI: 12.3 vs. 30.9 % p < 0.0001; IF: 15.9 vs. 24.1 %; p < 0.001). The IMRT technique and IF target volume delineation allow a significant dose escalation and an increase in TCP. IMRT results in an improved sparing of OARs as compared with 3D-CRT at equivalent dose levels. (orig.) [German] Das Potenzial der intensitaetsmodulierten Strahlentherapie (IMRT) soll im Rahmen der FDG-PET basierten Bestrahlungsplanung des lokal fortgeschrittenen nichtkleinzelligen Bronchialkarzinoms (LA-NSCLC) fuer 2 Zielvolumenansaetze (Involved-Field-Bestrahlung, IF) sowie elektive Nodalbestrahlung (ENI) geprueft und mit der 3-D-konformalen Strahlentherapie (3-D

  1. [Conformal radiotherapy of prostatic cancer: a general review].

    Science.gov (United States)

    Chauvet, B; Oozeer, R; Bey, P; Pontvert, D; Bolla, M

    1999-01-01

    Recent progress in radiotherapeutic management of localized prostate cancer is reviewed. Clinical aspects--including dose-effect beyond 70 Gy, relative role of conformal radiation therapy techniques and of early hormonal treatment--are discussed as well as technical components--including patient immobilization, organ motion, prostate contouring, beam arrangement, 3-D treatment planning and portal imaging. The local control and biological relapse-free survival rates appear to be improved by high dose conformal radiotherapy from 20 to 30% for patients with intermediate and high risk of relapse. A benefit of overall survival is expected but not yet demonstrated. Late reactions, especially the rectal toxicity, remain moderate despite the dose escalation. However, conformal radiotherapy demands a high precision at all steps of the procedure.

  2. Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors; Comparaison entre dosimetries classique et conformationnelle dans l'irradiation de tumeurs cerebrales

    Energy Technology Data Exchange (ETDEWEB)

    Caudrelier, J.M.; Auliard, A.; Sarrazin, T.; Gibon, D.; Coche-Dequeant, B.; Castelain, B. [Centre de Lutte Contre le Cancer Oscar-Lambret, 59 - Lille (France)

    2001-06-01

    Comparison between conventional and three-dimensional conformal treatment planning for radiotherapy of cerebral tumors. Purpose. - We prospectively compared a conventional treatment planning (PT2D) and 3-dimensional conformal treatment planning (PT3D) for radiotherapy of cerebral tumours. Patients and methods.- Patients treated between 1/10/98 and 1/4/99 by irradiation for cerebral tumours were analysed. For each case, we planned PT2D using conventional orthogonal x-ray films, and afterward, PT3D using CT scan. Gross tumor volume, planning target volume and normal tissue volumes were defined. Dose was prescribed according to report 50 of the International Commission on Radiation Units and Measurements (ICRU). We compared surfaces of sagittal view targets defined on PT2D and PT3D and called them S2D and S3D, respectively. Irradiated volumes by 90% isodoses (VE-90%) and normal tissue volumes irradiated by 20, 50, 90% isodoses were calculated and compared using Student's paired t-test. Results. -There was a concordance of 84% of target surfaces defined on PT2D and PT3D. Percentages of target surface under- or-over defined by PT2D were 16 and 13% respectively. VE-90% was decreased by 15% (p = 0.07) with PT3D. Normal brain volume irradiated by 90% isodose was decreased by 27% with PT3D (p = 0.04). Conclusion.- For radiotherapy of cerebral tumors using only coplanar beams, PT3D leads to a reduction of normal brain tissue irradiated. We recommend PT3D for radiotherapy of cerebral tumors, particularly for low-grade or benign tumors (meningiomas, neuromas, etc.). (authors)

  3. Loco-regional conformal radiotherapy of the breast: delineation of the regional lymph node clinical target volumes in treatment position.

    NARCIS (Netherlands)

    Dijkema, I.M.; Hofman, P.; Raaijmakers, C.P.; Lagendijk, J.J.; Battermann, J.J.; Hillen, B.

    2004-01-01

    BACKGROUND AND PURPOSE: As the location of the regional lymph nodes (LNs) of the breast varies largely between patients and may be dependant on the position of the arm, adequate localization of these nodes is mandatory in order to fully take advantage of optimized conformal radiotherapy. For this

  4. TREATMENT OF COGNITIVE DISORDERS IN HYPERTENSIVE PATIENTS EXPOSED TO RADIATION

    Directory of Open Access Journals (Sweden)

    I. V. Podsonnaja

    2008-01-01

    Full Text Available Aim. To assess cognitive functions in liquidators of Chernobyl accident (LCA consequences suffering from arterial hypertension (HT and to study efficacy of their treatment with cortexin (complex of polypeptide fractions.Material and methods. 60 men (aged of 39-60 y.o., LCA with HT and cognitive disorders were included in the study. Cortexin was used (10 mg intramusculary during 10 days for one or two courses. Efficacy of treatment was estimated by neuropsychological tests (Shulte test , A.R. Lurija test, serial account, test "feeling, activity, mood", headache intensity on VAS scale before and in 10 days of treatment as well as 6 and 12 months after treatment.Results. Cortexin therapy (2 courses increased of mental processes speed and retention of information volume, reduced personal and behavioral disorders.Conclusion. Treatment with cortexin (2 courses improves cognitive functions in LCA with HT.

  5. Combined Treatment Effects of Radiation and Immunotherapy: Studies in an Autochthonous Prostate Cancer Model

    Energy Technology Data Exchange (ETDEWEB)

    Wada, Satoshi [Department of Oncology, James Buchanan Brady Urological Institute, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Harris, Timothy J.; Tryggestad, Erik [Department of Radiation Oncology and Molecular Radiation Sciences, James Buchanan Brady Urological Institute, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Yoshimura, Kiyoshi [Department of Oncology, James Buchanan Brady Urological Institute, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Zeng, Jing [Department of Radiation Oncology and Molecular Radiation Sciences, James Buchanan Brady Urological Institute, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Yen, Hung-Rong; Getnet, Derese; Grosso, Joseph F.; Bruno, Tullia C. [Department of Oncology, James Buchanan Brady Urological Institute, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); De Marzo, Angelo M. [Department of Pathology, James Buchanan Brady Urological Institute, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); Department of Urology, James Buchanan Brady Urological Institute, Johns Hopkins Sidney Kimmel Comprehensive Cancer Center, Johns Hopkins University School of Medicine, Baltimore, Maryland (United States); and others

    2013-11-15

    Purpose: To optimize the combination of ionizing radiation and cellular immunotherapy using a preclinical autochthonous model of prostate cancer. Methods and Materials: Transgenic mice expressing a model antigen under a prostate-specific promoter were treated using a platform that integrates cone-beam CT imaging with 3-dimensional conformal therapy. Using this technology we investigated the immunologic and therapeutic effects of combining ionizing radiation with granulocyte/macrophage colony-stimulating factor-secreting cellular immunotherapy for prostate cancer in mice bearing autochthonous prostate tumors. Results: The combination of ionizing radiation and immunotherapy resulted in a significant decrease in pathologic tumor grade and gross tumor bulk that was not evident with either single-modality therapy. Furthermore, combinatorial therapy resulted in improved overall survival in a preventive metastasis model and in the setting of established micrometastases. Mechanistically, combined therapy resulted in an increase of the ratio of effector-to-regulatory T cells for both CD4 and CD8 tumor-infiltrating lymphocytes. Conclusions: Our preclinical model establishes a potential role for the use of combined radiation-immunotherapy in locally advanced prostate cancer, which warrants further exploration in a clinical setting.

  6. Dietary flaxseed administered post thoracic radiation treatment improves survival and mitigates radiation-induced pneumonopathy in mice

    Directory of Open Access Journals (Sweden)

    Arguiri Evguenia

    2011-06-01

    BAL fluid revealed a significant decrease of specific inflammatory cytokines in FS-fed mice. Conclusions Dietary FS given post-XRT mitigates radiation effects by decreasing pulmonary fibrosis, inflammation, cytokine secretion and lung damage while enhancing mouse survival. Dietary supplementation of FS may be a useful adjuvant treatment mitigating adverse effects of radiation in individuals exposed to inhaled radioisotopes or incidental radiation.

  7. Dietary flaxseed administered post thoracic radiation treatment improves survival and mitigates radiation-induced pneumonopathy in mice.

    Science.gov (United States)

    Christofidou-Solomidou, Melpo; Tyagi, Sonia; Tan, Kay-See; Hagan, Sarah; Pietrofesa, Ralph; Dukes, Floyd; Arguiri, Evguenia; Heitjan, Daniel F; Solomides, Charalambos C; Cengel, Keith A

    2011-06-24

    specific inflammatory cytokines in FS-fed mice. Dietary FS given post-XRT mitigates radiation effects by decreasing pulmonary fibrosis, inflammation, cytokine secretion and lung damage while enhancing mouse survival. Dietary supplementation of FS may be a useful adjuvant treatment mitigating adverse effects of radiation in individuals exposed to inhaled radioisotopes or incidental radiation.

  8. Quality of coverage: conformity measures for stereotactic radiosurgery.

    Science.gov (United States)

    Wu, Q-R Jackie; Wessels, B W; Einstein, D B; Maciunas, R J; Kim, E Y; Kinsella, T J

    2003-01-01

    In radiosurgery, conformity indices are often used to compare competing plans, evaluate treatment techniques, and assess clinical complications. Several different indices have been reported to measure the conformity of the prescription isodose to the target volume. The PITV recommended in the Radiation Therapy Oncology Group (RTOG) radiosurgery guidelines, defined as the ratio of the prescription isodose volume (PI) over the target volume (TV), is probably the most frequently quoted. However, these currently used conformity indices depend on target size and shape complexity. The objectives of this study are to systematically investigate the influence of target size and shape complexity on existing conformity indices, and to propose a different conformity index-the conformity distance index (CDI). The CDI is defined as the average distance between the target and the prescription isodose line. This study examines five case groups with volumes of 0.3, 1.0, 3.0, 10.0, and 30.0 cm(3). Each case group includes four simulated shapes: a sphere, a moderate ellipsoid, an extreme ellipsoid, and a concave "C" shape. Prescription dose coverages are generated for three simplified clinical scenarios, i.e., the PI completely covers the TV with 1 and 2 mm margins, and the PI over-covers one half of the TV with a 1 mm margin and under-covers the other half with a 1 mm margin. Existing conformity indices and the CDI are calculated for these five case groups as well as seven clinical cases. When these values are compared, the RTOG PITV conformity index and other similar conformity measures have much higher values than the CDI for smaller and more complex shapes. With the same quality of prescription dose coverage, the CDI yields a consistent conformity measure. For the seven clinical cases, we also find that the same PITV values can be associated with very different conformity qualities while the CDI predicts the conformity quality accurately. In summary, the proposed CDI provides

  9. Counseling patients about sexual health when considering post-prostatectomy radiation treatment

    Science.gov (United States)

    Wittmann, D; Montie, J E; Hamstra, D A; Sandler, H; Wood, D P

    2009-01-01

    Prostate cancer is the second most frequently diagnosed cancer in men in the United States. Many men with clinically localized prostate cancer survive for 15 years or more. Although early detection and successful definitive treatments are increasingly common, a debate regarding how aggressively to treat prostate cancer is ongoing because of the effect of aggressive treatment on the quality of life, including sexual functioning. We examined current research on the effect of post-prostatectomy radiation treatment on sexual functioning, and suggest a way in which patient desired outcomes might be taken into consideration while making decisions with regard to the timing of radiation therapy after prostatectomy. PMID:19609297

  10. Neutron radiation therapy: application of advanced technology to the treatment of cancer

    CERN Document Server

    Maughan, R L; Kota, C; Burmeister, J; Porter, A T; Forman, J D; Blosser, H G; Blosser, E; Blosser, G

    1999-01-01

    The design and construction of a unique superconducting cyclotron for use in fast neutron radiation therapy is described. The clinical results obtained in the treatment of adenocarcinoma of the prostate with this accelerator are presented. Future use of the boron neutron capture reaction as a means of enhancing fast neutron therapy in the treatment of patients with brain tumors (glioblastoma multiforme) is also discussed.

  11. Hyperbaric oxygen in the treatment of radiation-induced optic neuropathy

    Energy Technology Data Exchange (ETDEWEB)

    Guy, J.; Schatz, N.J.

    1986-08-01

    Four patients with radiation-induced optic neuropathies were treated with hyperbaric oxygen. They had received radiation therapy for treatment of pituitary tumors, reticulum cell sarcoma, and meningioma. Two presented with amaurosis fugax before the onset of unilateral visual loss and began hyperbaria within 72 hours after development of unilateral optic neuropathy. Both had return of visual function to baseline levels. The others initiated treatment two to six weeks after visual loss occurred in the second eye and had no significant improvement of vision. Treatment consisted of daily administration of 100% oxygen under 2.8 atmospheres of pressure for 14-28 days. There were no medical complications of hyperbaria. While hyperbaric oxygen is effective in the treatment of radiation-induced optic neuropathy, it must be instituted within several days of deterioration in vision for restoration of baseline function.

  12. Helical Electron Avoidance Radiation Therapy (HEART) for Breast Cancer Treatment

    Science.gov (United States)

    2005-04-01

    3. K. Li, and L. Ma, "Selective Source Blocking for Treatment of Trigeminal Neuralgia Based on Analytical Gamma Knife Dose Modeling", Phys. Med. Biol...radiosurgery of trigeminal neuralgia " Appl. Clin. Med. Phy., Vol 1(4) 116-119, 2000. (2) Major Presentations 1. The 4 th Era of Hope Conference...treatment planning", Med. Phys. 31(2004) No. 6,1824. 4. L. Ma, and K. Li, " Selective source blocking for treatment of trigeminal neuralgia based on

  13. Dosimetric comparison of different radiation treatment modalities for acoustic neuromas

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dong Wook; Chung, Weon Kuu [Kyung Hee University Hospital at Gangdong, Seoul (Korea, Republic of); Shin, Dong Oh [Kyung Hee Medical Center, Seoul (Korea, Republic of); Shin, Dongho [National Cancer Center, Goyang (Korea, Republic of)

    2014-11-15

    The dosimetric differences for intensity-modulatedradiotherapy (IMRT), volumetric modulated arc therapy (VMAT), proton therapy(PROTON) and stereotactic radiosurgery (SRS) in patient with acoustic neuroma (AN) were compared by using the dose-volume histogram (DVH). In the present study, we estimated the dosimetric differences for patient with AN who received different treatment modalities. In this study, we found proton therapy is relatively effective treatment techniques than the other.

  14. Radiation therapy, an important mode of treatment for head and neck chemodectomas

    Energy Technology Data Exchange (ETDEWEB)

    Verniers, D.A. (Dr. Daniel den Hoad Cancer Centre, Rotterdam (Netherlands)); Keus, R.B.; Schouwenburg, P.F.; Bartelink, H. (Nederlands Kanker Inst. ' Antoni van Leeuwenhoekhuis' , Amsterdam (Netherlands))

    1992-05-01

    Between 1970 and 1990, 22 patients with 44 chemodectomas in the head and neck region were seen at the Netherlands Cancer Institute in Amsterdam. All patients were treated with radiation therapy (17 patients with radiation therapy only and 5 in combination with surgery). One patient was treated two times with an interval of 12 years at each side of the neck. Standard dose was 50 Gy in 25 fractions over 5 weeks. A radiation portal arrangement with oblique fields with paired wedges was used most frequently. The follow-up period ranged from 1 year to 20 years. Two recurrences at 2 and 9 years after treatment were observed. The actuarial local control rate was 88% at 10 years follow-up. Comparison of the results of surgery and radiotherapy demonstrates that radiation therapy is an effective treatment modality without mutilation or severe late morbidity for chemodectomas in the head and neck region. (Author).

  15. Vacuum-UV radiation at 185 nm in water treatment--a review.

    Science.gov (United States)

    Zoschke, Kristin; Börnick, Hilmar; Worch, Eckhard

    2014-04-01

    The vacuum-UV radiation of water results in the in situ generation of hydroxyl radicals. Low-pressure mercury vapor lamps which emit at 185 nm are potential sources of VUV radiation. The scope of this article is to give an overview of the application of VUV radiation at 185 nm for water treatment including the transformation of inorganic and organic water constituents, and the disinfection efficiency. Another focus is on the generation of ozone by VUV radiation from oxygen or air and the application of the produced ozone in combination with VUV irradiation of water in the VUV/O3 process. The advantages and limitation of the VUV process at 185 nm as well as possible applications in water treatment are outlined.

  16. Surgical treatment of radiation injuries of the colon and rectum

    Energy Technology Data Exchange (ETDEWEB)

    Jao, S.W.; Beart, R.W. Jr.; Gunderson, L.L.

    1986-02-01

    Between 1950 and 1983, radiation-induced proctitis was diagnosed proctoscopically in 720 patients at the Mayo Clinic. Sixty-two patients with severe colorectal symptoms were treated surgically. The interval from cessation of radiotherapy to onset of symptoms ranged from 3 weeks to 24 months (mean 33 months). The 62 patients underwent a total of 143 operations with 8 operative deaths (13 percent), and 40 patients (65 percent) had 61 complications. The morbidity rate was lower after colostomy alone (44 percent in 27 patients) than after more aggressive operations (80 percent in 35 patients). Transverse loop colostomy and descending colostomy were safer than sigmoid colostomy. The dissection adhesions, opening of tissue planes, and careless manipulation of intestine may result in necrosis and perforation of the intestine, bladder, or vaginal wall; these were the main causes of fecal and other internal fistulas in our study.

  17. Contribution of radiation treatment to the breast conserving therapy

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, Sho; Shibuya, Hitoshi; Matsumoto, Satoru; Hoshina, Masao (Tokyo Medical and Dental Univ. (Japan). School of Medicine); Nishi, Tsunehiro; Kawahito, Hirotsugu; Inoue, Yoshihiro; Horiuchi, Junichi

    1991-11-01

    Breast-conserving surgery followed by irradiation for the early breast cancer has become the alternative therapy to mastectomy in European countries and U.S.A., but not yet commonly employed in our country. Sixty-one breasts in 60 patients treated with the above mentioned therapy from September 1983 to April 1991 were surveyed. Although the distant metastases of bone and pleura were found in one patient about four years after the therapy, neither failure of local control nor death was disclosed among them. Moderate fibrotic change with slight telangiectsia was found in only one patient. Otherwise, late effect of radiation was generally found to be mild and acceptable. (author) 59 refs.

  18. Cerenkov radiation-induced phototherapy for depth-independent cancer treatment (Conference Presentation)

    Science.gov (United States)

    Akers, Walter J.; Achilefu, Samuel; Kotagiri, Nalinikanth

    2017-02-01

    Light emitted as the result of high-energy particle transport through biological tissues (Cerenkov radiation) can be exploited for noninvasive diagnostic imaging using high sensitivity scientific cameras. We have investigated the energy transfer potential of Cerenkov radiation, discovering a new phototherapeutic technique for treatment of localized and disseminated cancers. This technique, Cerenkov radiation-induced phototherapy (CRIT), like photodynamic therapy, requires the presence of both light and photosensitive agent together to induce cytotoxicity and effective cancer treatment. But unlike conventional phototherapy strategies in which tissue ablation or activation of photoactive molecules is limited to superficial structures, radiation-induced phototherapy enables phototherapy delivery to the tumor sites throughout the body. Titanium oxide nanoparticles, which produce cytotoxic reactive oxygen species upon irradiation with UV light, were targeted to tumor tissue by surface decoration with transferrin. Subsequent administration of tumor-avid radiotracer, 18-fluorodeoxyglucose (18FDG) provided localized UV light source via Cerenkov radiation. Treatment of tumor-bearing mice with the combination of Titanium nanoparticles and 18FDG resulted in effective reduction in tumor growth, while individual agents were not therapeutic. This new strategy in cancer therapy extends the reach of phototherapy beyond what was previously possible, with potential for treatment of cancer metastases and rescue from treatment resistance.

  19. Emergency radiation treatment for paraplegia caused by extradural leukemic invasion; Report of 2 cases

    Energy Technology Data Exchange (ETDEWEB)

    Murakami, Masao; Kuroda, Yasumasa; Sano, Akira (Tenri Hospital, Nara (Japan)) (and others)

    1993-02-01

    We present 2 cases of emergency radiation therapy for paraplegia caused by extradural leukemic invasion. Tumor regression was noted at 12 Gy, and complete disappearance at 20 Gy. MRI proved useful in early detection and in the follow-up. They were doing well for 14 months after irradiation. Irradiation should be the treatment of first choice for these tumors, and the detail such as radiation field, total dosage should be determined in consideration of other therapeutic measures. (author).

  20. Conformational Transitions

    Science.gov (United States)

    Czerminski, Ryszard; Roitberg, Adrian; Choi, Chyung; Ulitsky, Alexander; Elber, Ron

    1991-10-01

    Two computational approaches to study plausible conformations of biological molecules and the transitions between them are presented and discussed. The first approach is a new search algorithm which enhances the sampling of alternative conformers using a mean field approximation. It is argued and demonstrated that the mean field approximation has a small effect on the location of the minima. The method is a combination of the LES protocol (Locally Enhanced Sampling) and simulated annealing. The LES method was used in the past to study the diffusion pathways of ligands from buried active sites in myoglobin and leghemoglobin to the exterior of the protein. The present formulation of LES and its implementation in a Molecular Dynamics program is described. An application for side chain placement in a tetrapeptide is presented. The computational effort associated with conformational searches using LES grows only linearly with the number of degrees of freedom, whereas in the exact case the computational effort grows exponentially. Such saving is of course associated with a mean field approximation. The second branch of studies pertains to the calculation of reaction paths in large and flexible biological systems. An extensive mapping of minima and barriers for two different tetrapeptides is calculated from the known minima and barriers of alanine tetrapeptide which we calculated recently.1 The tetrapeptides are useful models for the formation of secondary structure elements since they are the shortest possible polymers of this type which can still form a complete helical turn. The tetrapeptides are isobutyryl-val(χ1=60)-ala-ala and isobutyryl-val(χ1=-60)-ala-ala. Properties of the hundreds of minima and of the hundreds intervening barriers are discussed. Estimates for thermal transition times between the many conformers (and times to explore the complete phase space) are calculated and compared. It is suggested that the most significant effect of the side chain size is

  1. Conformal radiotherapy for locally advanced juvenile nasopharyngeal angio-fibroma

    Directory of Open Access Journals (Sweden)

    Supriya Mallick

    2015-01-01

    Full Text Available Purpose: To assess the efficacy of radiation in the treatment of juvenile nasopharyngeal angiofibroma (JNA. Materials and Methods: Data were retrieved for JNA treated with radiotherapy from 1987-2012. The demographics, treatment and outcome data were recorded in predesigned proforma. Results: Data of 32 patients were retrieved. Median age was 17 years (range: 12-33 years. All patients received radiation because of refractory, residual or unresectable locally advanced disease. All patients were planned with a three-dimensional conformal technique (3DCRT. The median radiation dose was 30 Gray (range: 30-45 Gray. Median follow-up was 129 months (range: 1-276 months. At the last follow-up, 13 patients were found to have a radiological complete response. Two patients progressed 38 and 43 months after completion of treatment and opted for alternative treatment. One patient developed squamous cell carcinoma of the nasal ale 15 years after radiation. Conclusion: Conformal radiotherapy shows promise as an alternative treatment approach for locally advanced JNA and confers long-term disease control with minimal toxicity.

  2. Simulation and Design of X-Band Conformal Antenna on Airborne Craft with Omni-directional Radiation%X波段全向共形机载天线的仿真与设计

    Institute of Scientific and Technical Information of China (English)

    韩振平; 钱祖平; 倪为民; 刘宗全

    2011-01-01

    针对工作于X频段的机载雷达天线的技术设计,使该天线由矩形平面天线与柱体共形,通过共面波导方式对其进行馈电.天线单元采用介电常数2.55,厚度为0.2mm的薄介质板.利用HFSS12对平面天线和共形天线进行仿真设计,对比了平面天线与共形天线的阻抗特性和辐射特性的变化.实验结果表明,共形后的天线带宽变大,增益提高,波束宽度展宽.在X波段内实现了低仰角扫描和方位面的全向扫描,实测阻抗带宽为7.0~12.5GHz,最大增益可达4dB,辐射特性稳定,满足机载天线的性能指标,可用作机载雷达天线单元.%A cylindrical conformal antenna operation at X band is designed. Firstly, a planar antenna is designed and analyzed, and then it is mounted on a cylindrical surface to form a conform antenna. It is fed by CPW and the permittivity of the substrate is 2.55 and its thickness is only 0.2mm. It is simulated and optimized by using the soft of HFSS 12. Comparing the impedance characteristic and radiation patterns between the planar antenna and the conformal antenna, the experimental results show the conformal antenna has a broader bandwidth and 3dB beam-width and higher gain than the planar antenna, and it has low elevation scanning and Omni-directional radiation patterns at the"X band. The measured impedance bandwidth of conformal antenna covers from 7.0~12.5GHz, the maximum gain is 4dB and radiation performance is stable. The antenna satisfies the capability of airborne antenna well so it can be used in the airborne radar system.

  3. Pelvic radiation - discharge

    Science.gov (United States)

    Radiation of the pelvis - discharge; Cancer treatment - pelvic radiation; Prostate cancer - pelvic radiation; Ovarian cancer - pelvic radiation; Cervical cancer - pelvic radiation; Uterine cancer - pelvic radiation; Rectal cancer - pelvic radiation

  4. Optimization of the CHARMM additive force field for DNA: Improved treatment of the BI/BII conformational equilibrium.

    Science.gov (United States)

    Hart, Katarina; Foloppe, Nicolas; Baker, Christopher M; Denning, Elizabeth J; Nilsson, Lennart; Mackerell, Alexander D

    2012-01-10

    The B-form of DNA can populate two different backbone conformations: BI and BII, defined by the difference between the torsion angles ε and ζ (BI = ε-ζ 0). BI is the most populated state, but the population of the BII state, which is sequence dependent, is significant and accumulating evidence shows that BII affects the overall structure of DNA, and thus influences protein-DNA recognition. This work presents a reparametrization of the CHARMM27 additive nucleic acid force field to increase the sampling of the BII form in MD simulations of DNA. In addition, minor modifications of sugar puckering were introduced to facilitate sampling of the A form of DNA under the appropriate environmental conditions. Parameter optimization was guided by quantum mechanical data on model compounds, followed by calculations on several DNA duplexes in the condensed phase. The selected optimized parameters were then validated against a number of DNA duplexes, with the most extensive tests performed on the EcoRI dodecamer, including comparative calculations using the Amber Parm99bsc0 force field. The new CHARMM model better reproduces experimentally observed sampling of the BII conformation, including sampling as a function of sequence. In addition, the model reproduces the A form of the 1ZF1 duplex in 75 % ethanol, and yields a stable Z-DNA conformation of duplex (GTACGTAC) in its crystal environment. The resulting model, in combination with a recent reoptimization of the CHARMM27 force field for RNA, will be referred to as CHARMM36.

  5. Cancer patients with cardiac pacemakers needing radiation treatment: A systematic review

    Directory of Open Access Journals (Sweden)

    Anusheel Munshi

    2013-01-01

    Full Text Available With improving average life expectancy of individuals in most countries, there has been increase in the incidence of cardiovascular diseases and cancers. Radiation oncologists therefore are likely to encounter an increasing number of cancer patients with in situ cardiac pacemaker devices needing radiation treatments. Pacemaker technology has advanced rapidly in recent years. As a result, the potential interactions of these devices with radiation therapy have changed since American Association of Physicists in Medicine (AAPM issued guidelines in 1994. Current approaches to treatment in patients who have these devices vary among radiation oncology centers. Furthermore, the recommendations given by the devices′ manufacturers differ considerably. Common knowledge about pacemaker in radiation oncology community is vital as radiation management needs to be tailored to individual patients in accordance to the information of available for the device. Some general practical guidelines can be gleaned from the literature. It is felt that more robust information is required using web based database sharing to develop total safe practice guidelines in such patients. This article reviews the information available to help create such guidelines and presents recommendations for treatment in this increasingly common clinical situation.

  6. Treatment modalities of oral mucositis after radiation of head and neck cancers; Prise en charge des mucites apres radiotherapie des cancers des voies aerodigestives superieures

    Energy Technology Data Exchange (ETDEWEB)

    Lapeyre, M.; Charra-Brunaud, C.; Kaminsky, M.C.; Geoffrois, L.; Dolivet, G.; Pourel, N.; Marchal, C.; Bey, P.; Maire, F.; Simon, M. [Centre Alexis-Vautrin, 54 - Vandoeuvre-les-Nancy (France); Toussaint, B. [Hopital Central, Service de Chirurgie ORL, 54 - Nancy (France)

    2001-11-01

    Acute mucositis is common after radiotherapy for head and neck cancers. During the past 3 decades, there was a gradual evolution in the treatment modalities for locally advanced carcinomas (concomitant radio-chemotherapy, accelerated radiotherapy). These new strategies are accompanied by an increase in early mucosal reactions. At the present time, there is no widely accepted prophylaxis or effective treatment. Many traditional remedies or new agents seem ineffective (Sucralfate, Chlorhexidine, GM-CSF, Silver nitrate, Prostaglandin, anti-oxidants, Benzydamine hydrochloride), while others seem promising (Povidone-iodine, nonabsorbable antibiotic lozenges and anti-fungal, local GM-CSF, Glutamide, Low-energy laser, corticosteroids). Radioprotectors are controversial and should be only used in experimental protocols and not in routine practice. However, some recommendations can be proposed: general prevention and global care before cancer therapy should be systematic (oral hygiene, dental and periodontal treatment, advice to avoid the use of tobacco and alcohol); frequent oral rinsing with a bland mouthwash (Povidone-iodine or others) should be used at the start of treatment because there are significant modifications of the oral microflora increased by a disturbed salivary flow; these mouthwashes could be associated with nonabsorbable antibiotic lozenges or anti-fungal topical (bicarbonates, Amphotericine B); Systematic percutaneous fluoroscopic gastrostomy should be decided before any aggressive treatments (concomitant radio-chemotherapy, accelerated radiotherapy); pain should be controlled; finally, the radiation technique should be optimized (mucosal sparing block, conformal radiotherapy and intensity modulated radiation therapy). (authors)

  7. Randomized Trial Comparing Conventional-Dose With High-Dose Conformal Radiation Therapy in Early-Stage Adenocarcinoma of the Prostate: Long-Term Results From Proton Radiation Oncology Group/American College of Radiology 95-09

    Science.gov (United States)

    Zietman, Anthony L.; Bae, Kyounghwa; Slater, Jerry D.; Shipley, William U.; Efstathiou, Jason A.; Coen, John J.; Bush, David A.; Lunt, Margie; Spiegel, Daphna Y.; Skowronski, Rafi; Jabola, B. Rodney; Rossi, Carl J.

    2010-01-01

    Purpose To test the hypothesis that increasing radiation dose delivered to men with early-stage prostate cancer improves clinical outcomes. Patients and Methods Men with T1b-T2b prostate cancer and prostate-specific antigen ≤ 15 ng/mL were randomly assigned to a total dose of either 70.2 Gray equivalents (GyE; conventional) or 79.2 GyE (high). No patient received androgen suppression therapy with radiation. Local failure (LF), biochemical failure (BF), and overall survival (OS) were outcomes. Results A total of 393 men were randomly assigned, and median follow-up was 8.9 years. Men receiving high-dose radiation therapy were significantly less likely to have LF, with a hazard ratio of 0.57. The 10-year American Society for Therapeutic Radiology and Oncology BF rates were 32.4% for conventional-dose and 16.7% for high-dose radiation therapy (P < .0001). This difference held when only those with low-risk disease (n = 227; 58% of total) were examined: 28.2% for conventional and 7.1% for high dose (P < .0001). There was a strong trend in the same direction for the intermediate-risk patients (n = 144; 37% of total; 42.1% v 30.4%, P = .06). Eleven percent of patients subsequently required androgen deprivation for recurrence after conventional dose compared with 6% after high dose (P = .047). There remains no difference in OS rates between the treatment arms (78.4% v 83.4%; P = .41). Two percent of patients in both arms experienced late grade ≥ 3 genitourinary toxicity, and 1% of patients in the high-dose arm experienced late grade ≥ 3 GI toxicity. Conclusion This randomized controlled trial shows superior long-term cancer control for men with localized prostate cancer receiving high-dose versus conventional-dose radiation. This was achieved without an increase in grade ≥ 3 late urinary or rectal morbidity. PMID:20124169

  8. Formalin treatment of radiation-induced hemorrhagic proctitis

    Energy Technology Data Exchange (ETDEWEB)

    Rubinstein, E.; Ibsen, T.; Rasmussen, R.B.; Reimer, E.; Sorensen, B.L.

    1986-01-01

    A 71-year-old man developed severe hemorrhagic proctitis 1 year after pelvic irradiation for carcinoma of the urinary bladder. Conservative treatment as well as performance of a colostomy failed to control the rectal bleeding. After irrigation of the rectum with a formalin solution the bleeding stopped, and no recurrence has been observed for the next 14 months.

  9. Imaging-Based Treatment Adaptation in Radiation Oncology

    NARCIS (Netherlands)

    Troost, E.G.; Thorwarth, D.; Oyen, W.J.G.

    2015-01-01

    In many tumor types, significant effort is being put into patient-tailored adaptation of treatment to improve outcome and preferably reduce toxicity. These opportunities first arose with the introduction of modern irradiation techniques (e.g., intensity-modulated radiotherapy) combined with function

  10. Systematic review of hyperbaric oxygen therapy for the treatment of radiation-induced skin necrosis.

    Science.gov (United States)

    Borab, Zachary; Mirmanesh, Michael D; Gantz, Madeleine; Cusano, Alessandro; Pu, Lee L Q

    2017-04-01

    Every year, 1.2 million cancer patients receive radiation therapy in the United States. Late radiation tissue injury occurs in an estimated 5-15% of these patients. Tissue injury can include skin necrosis, which can lead to chronic nonhealing wounds. Despite many treatments available to help heal skin necrosis such as hyperbaric oxygen therapy, no clinical guidelines exist and evidence is lacking. The purpose of this review is to identify and comprehensively summarize studies published to date to evaluate the effectiveness of hyperbaric oxygen therapy for the treatment of radiation-induced skin necrosis. Adhering to PRISMA guidelines, a systematic review of currently published articles was performed, evaluating the use of hyperbaric oxygen to treat skin necrosis. Eight articles were identified, including one observational cohort, five case series, and two case reports. The articles describe changes in symptoms and alteration in wound healing of radiation-induced skin necrosis after treatment with hyperbaric oxygen therapy. Hyperbaric oxygen therapy is a safe intervention with promising outcomes; however, additional evidence is needed to endorse its application as a relevant therapy in the treatment of radiation-induced skin necrosis.

  11. Ionizing radiation treatment to improve postharvest life and maintain quality of fresh guava fruit

    Science.gov (United States)

    Singh, S. P.; Pal, R. K.

    2009-02-01

    We investigated the potential of ionizing radiation for improving physiological responses, quality, and storage time of fresh guava fruit. Ionizing radiation treatment suppressed the respiration and ethylene production rates and thus retarded the process of fruit ripening during storage. Irradiation treatment also retarded the physical and biochemical changes associated with ripening such as firmness, titratable acidity, soluble solids content, and vitamin C during storage, but for doses higher than 0.25 kGy the vitamin C content decreased. The positive effects of ionizing radiation treatment on delayed fruit ripening and other quality attributes diminished during 22 days of storage at 10 °C. Thus, a combination of ionizing radiation with low-temperature storage (10 °C) did not have much synergistic effect on storage life and quality of guava fruit. In conclusion, ionizing radiation treatment of guava fruit with 0.25 kGy dose increased the postharvest life by 3-4 days, maintained fruit quality, and reduced the decay incidence. The optimal dose (0.25 kGy) for postharvest life extension of guava fruit may be exploited to provide phytosanitary security against many insect pests including fruit flies.

  12. Ionizing radiation treatment to improve postharvest life and maintain quality of fresh guava fruit

    Energy Technology Data Exchange (ETDEWEB)

    Singh, S.P. [Handling and Storage Laboratory, Division of Postharvest Technology, Indian Agricultural Research Institute (IARI), Pusa, New Delhi 110 012 (India)], E-mail: sukhvinder.singh@curtin.edu.au; Pal, R.K. [Handling and Storage Laboratory, Division of Postharvest Technology, Indian Agricultural Research Institute (IARI), Pusa, New Delhi 110 012 (India)

    2009-02-15

    We investigated the potential of ionizing radiation for improving physiological responses, quality, and storage time of fresh guava fruit. Ionizing radiation treatment suppressed the respiration and ethylene production rates and thus retarded the process of fruit ripening during storage. Irradiation treatment also retarded the physical and biochemical changes associated with ripening such as firmness, titratable acidity, soluble solids content, and vitamin C during storage, but for doses higher than 0.25 kGy the vitamin C content decreased. The positive effects of ionizing radiation treatment on delayed fruit ripening and other quality attributes diminished during 22 days of storage at 10 deg. C. Thus, a combination of ionizing radiation with low-temperature storage (10 deg. C) did not have much synergistic effect on storage life and quality of guava fruit. In conclusion, ionizing radiation treatment of guava fruit with 0.25 kGy dose increased the postharvest life by 3-4 days, maintained fruit quality, and reduced the decay incidence. The optimal dose (0.25 kGy) for postharvest life extension of guava fruit may be exploited to provide phytosanitary security against many insect pests including fruit flies.

  13. On radiation damage to normal tissues and its treatment. Pt. 2; Anti-inflammatory drugs

    Energy Technology Data Exchange (ETDEWEB)

    Michalowski, A.S. (MRC Cyclotron Unit, Hammersmith Hospital, London (United Kingdom))

    1994-01-01

    In addition to transiently inhibiting cell cycle progression and sterilizing those cells capable of proliferation, irradiation disturbs the homeostasis effected by endogenous mediators of intercellular communication (humoral component of tissue response to radiation). Changes in the mediator levels may modulate radiation effects either by a assisting a return to normality (e.g., through a rise in H-type cell lineage-specific growth factors) or by aggravating the damage. The latter mode is illustrated with reports on changes in eicosanoid levels after irradiation and on results of empirical treatment of radiation injuries with anti-inflammatory drugs. Prodromal, acute and chronic effects of radiation are accompanied by excessive production of eicosanoids (prostaglandins, prostacyclin, thromboxanes and leukotrienes). These endogenous mediators of inflammatory reactions may be responsible for the vasodilatation, vasoconstriction, increased microvascular permeability, thrombosis and chemotaxis observed after radiation exposure. Glucocorticoids inhibit eicosanoid synthesis primarily by interfering with phospholipase A[sub 2] whilst non-steroidal anti-inflammatory drugs prevent prostaglandin/thromboxane synthesis by inhibiting cycloxygenase. When administered after irradiation on empirical grounds, drugs belonging to both groups tend to attenuate a range of prodomal, acute and chronic effects of radiation in man and animals. Taken together, these two sets of observations are highly suggestive of a contribution of humoral factors to the adverse responses of normal tissues and organs to radiation. A full account of radiation damage should therefore consist of complementary descriptions of cellular and humoral events. Further studies on anti-inflammatory drug treatment of radiation damage to normal organs are justified and desirable. (orig.).

  14. Treatment of Head and Neck Paragangliomas With External Beam Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Dupin, Charles, E-mail: c.dupin@bordeaux.unicancer.fr [Department of Radiotherapy, Comprehensive Cancer Center, Institut Bergonié, Bordeaux (France); Lang, Philippe [Department of Radiotherapy, Pitié Salpétrière, Paris (France); Dessard-Diana, Bernadette [Department of Radiotherapy, Hopital Européen Georges Pompidou, Paris (France); Simon, Jean-Marc; Cuenca, Xavier; Mazeron, Jean-Jacques; Feuvret, Loïc [Department of Radiotherapy, Pitié Salpétrière, Paris (France)

    2014-06-01

    Purpose: To retrospectively assess the outcomes of radiation therapy in patients with head and neck paragangliomas. Methods and Materials: From 1990 to 2009, 66 patients with 81 head and neck paragangliomas were treated by conventional external beam radiation therapy in 25 fractions at a median dose of 45 Gy (range, 41.4-68 Gy). One case was malignant. The median gross target volume and planning target volume were 30 cm{sup 3} (range, 0.9-243 cm{sup 3}) and 116 cm{sup 3} (range, 24-731 cm{sup 3}), respectively. Median age was 57.4 years (range, 15-84 years). Eleven patients had multicentric lesions, and 8 had family histories of paraganglioma. Paragangliomas were located in the temporal bone, the carotid body, and the glomus vagal in 51, 18, and 10 patients, respectively. Forty-six patients had exclusive radiation therapy, and 20 had salvage radiation therapy. The median follow-up was 4.1 years (range, 0.1-21.2 years). Results: One patient had a recurrence of temporal bone paraganglioma 8 years after treatment. The actuarial local control rates were 100% at 5 years and 98.7% at 10 years. Patients with multifocal tumors and family histories were significantly younger (42 years vs 58 years [P=.002] and 37 years vs 58 years [P=.0003], respectively). The association between family predisposition and multifocality was significant (P<.001). Two patients had cause-specific death within the 6 months after irradiation. During radiation therapy, 9 patients required hospitalization for weight loss, nausea, mucositis, or ophthalmic zoster. Two late vascular complications occurred (middle cerebral artery and carotid stenosis), and 2 late radiation-related meningiomas appeared 15 and 18 years after treatment. Conclusion: Conventional external beam radiation therapy is an effective and safe treatment option that achieves excellent local control; it should be considered as a first-line treatment of choice for head and neck paragangliomas.

  15. Prophylactic treatment with a potent corticosteroid cream ameliorates radiodermatitis, independent of radiation schedule

    DEFF Research Database (Denmark)

    Ulff, Eva; Maroti, Marianne; Serup, Jörgen;

    2016-01-01

    schedules as well as for anatomical sites, skin type, breast size and BMI. Patients treated the irradiated area during the radiation period and two weeks following cessation of radiation. RESULTS: Patients receiving hypofraction RT developed less skin reactions than those treated with conventional RT...... in patients with breast cancer receiving adjuvant radiotherapy (RT) after surgery. In total, 202 patients were randomized to betamethasone-17-valerate cream or Essex® cream, a moisturizer. Treatment was assessed by RTOG clinical scoring. Patients' symptoms were recorded. The analyses were stratified for RT....... Treatment with a potent steroid resulted in clinically and statistically significantly less skin reactions (p

  16. Pelvic complications after definitive treatment of prostate cancer by interstitial or external beam radiation

    Energy Technology Data Exchange (ETDEWEB)

    Schellhammer, P.F.; El-Mahdi, A.M.

    1983-05-01

    Radiation complications, after definitive treatment of localized prostatic carcinoma by either external beam or interstitial implantation with Iodine-125 seeds, are reviewed. Late serious complications to immediately adjacent structures of the anterior rectal wall, prostatic urethra, bladder neck, and external sphincter occurred with similar frequency in both treatment groups. However, late serious complications of the remotely adjacent structures of the bladder, urethra, distal ureters, and circumferential rectal wall occurred more frequently in the external beam treatment series, a reflection of the fact that larger tissue volumes were irradiated. Rectal ulceration, while occurring in both treatment groups, was amenable to surgical correction or underwent spontaneous healing only in the 125I group. At this point in our experience, morbidity from late radiation complications has been less among those patients having interstitial implantation for definitive treatment of localized prostatic carcinoma.

  17. Assessment of normal tissue complications following prostate cancer irradiation: Comparison of radiation treatment modalities using NTCP models

    Energy Technology Data Exchange (ETDEWEB)

    Takam, Rungdham; Bezak, Eva; Yeoh, Eric E.; Marcu, Loredana [School of Chemistry and Physics, University of Adelaide, Adelaide SA 5000 (Australia) and Department of Medical Physics, Royal Adelaide Hospital, Adelaide SA 5000 (Australia); School of Medicine, University of Adelaide, Adelaide SA 5000 (Australia) and Department of Radiation Oncology, Royal Adelaide Hospital, Adelaide SA 5000 (Australia); School of Chemistry and Physics, University of Adelaide, Adelaide SA 5000 (Australia) and Faculty of Science, University of Oradea, Oradea 410086 (Romania)

    2010-09-15

    Purpose: Normal tissue complication probability (NTCP) of the rectum, bladder, urethra, and femoral heads following several techniques for radiation treatment of prostate cancer were evaluated applying the relative seriality and Lyman models. Methods: Model parameters from literature were used in this evaluation. The treatment techniques included external (standard fractionated, hypofractionated, and dose-escalated) three-dimensional conformal radiotherapy (3D-CRT), low-dose-rate (LDR) brachytherapy (I-125 seeds), and high-dose-rate (HDR) brachytherapy (Ir-192 source). Dose-volume histograms (DVHs) of the rectum, bladder, and urethra retrieved from corresponding treatment planning systems were converted to biological effective dose-based and equivalent dose-based DVHs, respectively, in order to account for differences in radiation treatment modality and fractionation schedule. Results: Results indicated that with hypofractionated 3D-CRT (20 fractions of 2.75 Gy/fraction delivered five times/week to total dose of 55 Gy), NTCP of the rectum, bladder, and urethra were less than those for standard fractionated 3D-CRT using a four-field technique (32 fractions of 2 Gy/fraction delivered five times/week to total dose of 64 Gy) and dose-escalated 3D-CRT. Rectal and bladder NTCPs (5.2% and 6.6%, respectively) following the dose-escalated four-field 3D-CRT (2 Gy/fraction to total dose of 74 Gy) were the highest among analyzed treatment techniques. The average NTCP for the rectum and urethra were 0.6% and 24.7% for LDR-BT and 0.5% and 11.2% for HDR-BT. Conclusions: Although brachytherapy techniques resulted in delivering larger equivalent doses to normal tissues, the corresponding NTCPs were lower than those of external beam techniques other than the urethra because of much smaller volumes irradiated to higher doses. Among analyzed normal tissues, the femoral heads were found to have the lowest probability of complications as most of their volume was irradiated to lower

  18. 3-D conformal treatment of prostate cancer to 74 Gy vs. high-dose-rate brachytherapy boost: A cross-sectional quality-of-life survey

    Energy Technology Data Exchange (ETDEWEB)

    Vordermark, Dirk [Univ. of Wuerzburg (DE). Dept. of Radiation Oncology] (and others)

    2006-09-15

    The effects of two modalities of dose-escalated radiotherapy on health-related quality of life (HRQOL) were compared. Forty-one consecutive patients were treated with a 3-D conformal (3-DC) boost to 74 Gy, and 43 with high-dose rate (HDR) brachytherapy boost (2x9 Gy), following 3-D conformal treatment to 46 Gy. Median age was 70 years in both groups, median initial PSA was 7.9 {mu}g/l in 3-DC boost patients and 8.1 {mu}g/l in HDR boost patients. Stage was 7 in 52% and 47%, respectively. HRQOL was assessed cross-sectionally using EORTC QLQ-C30 and organ-specific PR25 modules 3-32 (median 19) and 4-25 (median 14) months after treatment, respectively. Questionnaires were completed by 93% and 97% of patients, respectively. Diarrhea and insomnia scores were significantly increased in both groups. In the PR25 module, scores of 3-DC boost and HDR boost patients for urinary, bowel and treatment-related symptoms were similar. Among responders, 34% of 3-DC boost patients and 86% of HDR boost patients had severe erectile problems. Dose escalation in prostate cancer by either 3-DC boost to 74 Gy or HDR brachytherapy boost appears to result in similar HRQOL profiles.

  19. Radiation Therapy for the Treatment of Recurrent Glioblastoma: An Overview

    Energy Technology Data Exchange (ETDEWEB)

    Amelio, Dante; Amichetti, Maurizio, E-mail: amelio@atrep.it [ATreP-Agenzia Provinciale per la Protonterapia, Via F.lli Perini 181, Trento 38122 (Italy)

    2012-03-07

    Despite the therapeutic advances in neuro-oncology, most patients with glioblastoma ultimately experience local progression/relapse. Re-irradiation has been poorly viewed in the past, mainly due to the overestimated risk of side effects using conventional radiotherapy. To date, thanks to the improvement of several delivery techniques, together with improved imaging capabilities, re-irradiation is a viable salvage treatment option to manage such clinical scenario. A literature overview on the feasibility and efficacy of the different irradiation modalities for recurrent glioblastoma along with considerations on areas of improvement are provided.

  20. [Brain metastases: Focal treatment (surgery and radiation therapy) and cognitive consequences].

    Science.gov (United States)

    Reygagne, Emmanuelle; Du Boisgueheneuc, Foucaud; Berger, Antoine

    2017-04-01

    Brain metastases represent the first cause of malignant brain tumor. Without radiation therapy, prognosis was poor with fast neurological deterioration, and a median overall survival of one month. Nowadays, therapeutic options depend on brain metastases presentation, extra brain disease, performance status and estimated prognostic (DS GPA). Therefore, for oligometastatic brain patients with a better prognosis, this therapeutic modality is controversial. In fact, whole-brain radiation therapy improves neurological outcomes, but it can also induce late neuro-cognitive sequelae for long-term survivors of brain metastases. Thus, in this strategy for preserving good cognitive functions, stereotactic radiation therapy is a promising treatment. Delivering precisely targeted radiation in few high-doses in one to four brain metastases, allows to reduce radiation damage to normal tissues and it should allow to decrease radiation-induced cognitive decline. In this paper, we will discuss about therapeutic strategies (radiation therapy and surgery) with their neuro-cognitive consequences for brain metastases patients and future concerning preservation of cognitive functions. Copyright © 2016 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.

  1. Extrapleural pneumonectomy, photodynamic therapy and intensity modulated radiation therapy for the treatment of malignant pleural mesothelioma.

    Science.gov (United States)

    Du, Kevin L; Both, Stefan; Friedberg, Joseph S; Rengan, Ramesh; Hahn, Stephen M; Cengel, Keith A

    2010-09-01

    Intensity modulated radiation therapy (IMRT) has recently been proposed for the treatment of malignant pleural mesothelioma (MPM). Here, we describe our experience with a multimodality approach for the treatment of mesothelioma, incorporating extrapleural pneumonectomy, intraoperative photodynamic therapy and postoperative hemithoracic IMRT. From 2004-2007, we treated 11 MPM patients with hemithoracic IMRT, 7 of whom had undergone porfimer sodium-mediated PDT as an intraoperative adjuvant to surgical debulking. The median radiation dose to the planning treatment volume (PTV) ranged from 45.4-54.5 Gy. For the contralateral lung, V20 ranged from 1.4-28.5%, V5 from 42-100% and MLD from 6.8-16.5 Gy. In our series, 1 patient experienced respiratory failure secondary to radiation pneumonitis that did not require mechanical ventilation. Multimodality therapy combining surgery with increased doses of radiation using IMRT, and newer treatment modalities such as PDT , appears safe. Future prospective analysis will be needed to demonstrate efficacy of this approach in the treatment of malignant mesothelioma. Efforts to reduce lung toxicity and improve dose delivery are needed and provide the promise of improved local control and quality of life in a carefully chosen multidisciplinary approach.

  2. Excited atoms in the free-burning Ar arc: treatment of the resonance radiation

    Science.gov (United States)

    Golubovskii, Yu; Kalanov, D.; Gortschakow, S.; Baeva, M.; Uhrlandt, D.

    2016-11-01

    The collisional-radiative model with an emphasis on the accurate treatment of the resonance radiation transport is developed and applied to the free-burning Ar arc plasma. This model allows for analysis of the influence of resonance radiation on the spatial density profiles of the atoms in different excited states. The comparison of the radial density profiles obtained using an effective transition probability approximation with the results of the accurate solution demonstrates the distinct impact of transport on the profiles and absolute densities of the excited atoms, especially in the arc fringes. The departures from the Saha-Boltzmann equilibrium distributions, caused by different radiative transitions, are analyzed. For the case of the DC arc, the local thermodynamic equilibrium (LTE) state holds close to the arc axis, while strong deviations from the equilibrium state on the periphery occur. In the intermediate radial positions the conditions of partial LTE are fulfilled.

  3. Surgical treatment of radiation induced injuries of the intestine

    Energy Technology Data Exchange (ETDEWEB)

    Schmitt, E.H.; Symmonds, R.E.

    1981-12-01

    In the patient who has received high dose irradiation of the pelvis and abdomen, all abdominopelvic operations should be avoided, unless it is absolutely essential. Persisting obstruction, hemorrhage, intestinal perforation with peritonitis and with abscess and fistula formation are valid indications for surgical intervention. Ninety-three patients have been operated upon for these complications after irradiation. Some anastomotic dehiscence occurred in ten patients. Six operative deaths occurred. Of the 93 patients, 65 were managed by means of complete resection of the involved segment of intestine, followed by restoration of intestinal continuity by means of an end-to-end anastomosis. This is the treatment of choice when the involved area can be safely resected. In the absence of actual intestinal necrosis and when segments of strictured small intestine are adherent deep in the pelvis, and intestinal bypass procedure may represent the treatment of choice. This was accomplished in 20 patients, two of whom eventually required a second operation for resection of the bypassed segment of intestine.

  4. Late radiation side effects, cosmetic outcomes and pain in breast cancer patients after breast-conserving surgery and three-dimensional conformal radiotherapy. Risk-modifying factors

    Energy Technology Data Exchange (ETDEWEB)

    Hille-Betz, Ursula; Soergel, Philipp; Kundu, Sudip; Klapdor, Ruediger; Hillemanns, Peter [Hannover Medical School, Department of Obstetrics and Gynaecology, Hannover (Germany); Vaske, Bernhard [Hannover Medical School, Institute of Medical Biometry and Informatics, Hannover (Germany); Bremer, Michael; Henkenberens, Christoph [Hannover Medical School, Department of Radiation Oncology and Special Oncology, Hannover (Germany)

    2016-01-15

    The purpose of this work was to identify parameters influencing the risk of late radiation side effects, fair or poor cosmetic outcomes (COs) and pain in breast cancer patients after breast-conserving therapy (BCT) and three-dimensional conformal radiotherapy (3D-CRT). Between 2006 and 2013, 159 patients were treated at the Hannover Medical School. Physician-rated toxicity according to the LENT-SOMA criteria, CO and pain were assessed by multivariate analysis. LENT-SOMA grade 1-4 toxicity was observed as follows: fibrosis 10.7 %, telangiectasia 1.2 %, arm oedema 8.8 % and breast oedema 5.0 %. In addition, 15.1 % of patients reported moderate or severe breast pain, and 21.4 % complained about moderate or severe pain in the arm or shoulder. In multivariate analysis, axillary clearing (AC) was significantly associated with lymphoedema of the arm [odds ratio (OR) 4.37, p = 0.011, 95 % confidence interval (CI) 1.4-13.58]. Breast oedema was also highly associated with AC (OR 10.59, p = 0.004, 95 % CI 2.1-53.36), a ptosis grade 2/3 or pseudoptosis and a bra size ≥ cup C (OR 5.34, p = 0.029, 95 % CI 1.2-24.12). A ptosis grade 2/3 or pseudoptosis and a bra size ≥ cup C were the parameters significantly associated with an unfavourable CO (OR 3.19, p = 0.019, 95 % CI 1.2-8.4). Concerning chronic breast pain, we found a trend related to the prescribed radiation dose including boost (OR 1.077, p = 0.060, 95 % CI 0.997-1.164). Chronic shoulder or arm pain was statistically significantly associated with lymphoedema of the arm (OR 3.9, p = 0.027, 95 % CI 1.17-13.5). Chronic arm and breast oedema were significantly influenced by the extent of surgery (AC). Ptotic and large breasts were significantly associated with unfavourable COs and chronic breast oedema. Late toxicities exclusive breast pain were not associated with radiotherapy parameters. (orig.) [German] Ziel dieser Arbeit war es, Parameter zu identifizieren, die Spaetschaeden nach Radiotherapie, ein unguenstiges

  5. Adjuvant Radiation Therapy Treatment Time Impacts Overall Survival in Gastric Cancer

    Energy Technology Data Exchange (ETDEWEB)

    McMillan, Matthew T. [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Ojerholm, Eric [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Roses, Robert E., E-mail: Robert.Roses@uphs.upenn.edu [Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Plastaras, John P.; Metz, James M. [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Mamtani, Ronac [Department of Hematology/Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Karakousis, Giorgos C.; Fraker, Douglas L.; Drebin, Jeffrey A. [Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Stripp, Diana; Ben-Josef, Edgar [Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States); Datta, Jashodeep [Department of Surgery, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania (United States)

    2015-10-01

    Purpose: Prolonged radiation therapy treatment time (RTT) is associated with worse survival in several tumor types. This study investigated whether delays during adjuvant radiation therapy impact overall survival (OS) in gastric cancer. Methods and Materials: The National Cancer Data Base was queried for patients with resected gastric cancer who received adjuvant radiation therapy with National Comprehensive Cancer Network–recommended doses (45 or 50.4 Gy) between 1998 and 2006. RTT was classified as standard (45 Gy: 33-36 days, 50.4 Gy: 38-41 days) or prolonged (45 Gy: >36 days, 50.4 Gy: >41 days). Cox proportional hazards models evaluated the association between the following factors and OS: RTT, interval from surgery to radiation therapy initiation, interval from surgery to radiation therapy completion, radiation therapy dose, demographic/pathologic and operative factors, and other elements of adjuvant multimodality therapy. Results: Of 1591 patients, RTT was delayed in 732 (46%). Factors associated with prolonged RTT were non-private health insurance (OR 1.3, P=.005) and treatment at non-academic facilities (OR 1.2, P=.045). Median OS and 5-year actuarial survival were significantly worse in patients with prolonged RTT compared with standard RTT (36 vs 51 months, P=.001; 39 vs 47%, P=.005); OS worsened with each cumulative week of delay (P<.0004). On multivariable analysis, prolonged RTT was associated with inferior OS (hazard ratio 1.2, P=.002); the intervals from surgery to radiation therapy initiation or completion were not. Prolonged RTT was particularly detrimental in patients with node positivity, inadequate nodal staging (<15 nodes examined), and those undergoing a cycle of chemotherapy before chemoradiation therapy. Conclusions: Delays during adjuvant radiation therapy appear to negatively impact survival in gastric cancer. Efforts to minimize cumulative interruptions to <7 days should be considered.

  6. Which place for stem cell therapy in the treatment of acute radiation syndrome?

    Directory of Open Access Journals (Sweden)

    Jean-François Mayol

    2005-12-01

    Full Text Available Radiation-induced (RI tissue injuries can be caused by radiation therapy, nuclear accidents or radiological terrorism. Notwithstanding the complexity of RI pathophysiology, there are some effective approaches to treatment of both acute and chronic radiation damages. Cytokine therapy is the main strategy capable of preventing or reducing the acute radiation syndrome (ARS, and hematopoietic growth factors (GF are particularly effective in mitigating bone marrow (BM aplasia and stimulating hematopoietic recovery. However, first, as a consequence of RI stem and progenitor cell death, use of cytokines should be restricted to a range of intermediate radiation doses (3 to 7 Gy total body irradiation. Second, ARS is a global illness that requires treatment of damages to other tissues (epithelial, endothelial, glial, etc., which could be achieved using pleiotropic or tissue-specific cytokines. Stem cell therapy (SCT is a promising approach developed in the laboratory that could expand the ability to treat severe radiation injuries. Allogeneic hematopoietic stem cell transplantation (BM, mobilized peripheral blood and cord blood transplantation has been used in radiation casualties with variable success due to limiting toxicity related to the degree of graft histocompatibility and combined injuries. Ex vivo expansion should be used to augment cord blood graft size and/or promote very immature stem cells. Autologous SCT might also be applied to radiation casualties from residual hematopoietic stem and progenitor cells (HSPC. Stem cell plasticity of different tissues such as liver or skeletal muscle, may also be used as a source of hematopoietic stem cells. Finally, other types of stem cells such as mesenchymal, endothelial stem cells or other tissue committed stem cells (TCSC, could be used for treating damages to nonhematopoietic organs.

  7. FlexyDos3D: a deformable anthropomorphic 3D radiation dosimeter: radiation properties

    DEFF Research Database (Denmark)

    De Deene, Yves; Skyt, Peter Sandegaard; Hill, Robin

    2015-01-01

    Three dimensional radiation dosimetry has received growing interest with the implementation of highly conformal radiotherapy treatments. The radiotherapy community faces new challenges with the commissioning of image guided and image gated radiotherapy treatments (IGRT) and deformable image...... and oxygen concentration has also been investigated. The radiophysical properties of this new dosimeter are discussed including stability, spatial integrity, temperature dependence of the dosimeter during radiation, readout and storage, dose rate dependence and tissue equivalence....

  8. Role of the Technical Aspects of Hypofractionated Radiation Therapy Treatment of Prostate Cancer: A Review

    Energy Technology Data Exchange (ETDEWEB)

    Clemente, Stefania, E-mail: clemente_stefania@libero.it [Istituto di Ricovero e Cura a Carattere Scientifico Centro di Riferimento Oncologico della Basilicata Rionero in Vulture, Potenza (Italy); Nigro, Roberta [Azienda Sanitaria Locale Rieti, Roma (Italy); Oliviero, Caterina [Istituto di Ricovero e Cura a Carattere Scientifico Centro di Riferimento Oncologico della Basilicata Rionero in Vulture, Potenza (Italy); Marchioni, Chiara [Azienda Sanitaria Locale Rieti, Roma (Italy); Esposito, Marco [Azienda Sanitaria, Firenze (Italy); Giglioli, Francesca Romana [Azienda Ospedaliera Città della Salute e della Scienza di Torino, Torino (Italy); Mancosu, Pietro [Humanitas Clinical and Research Hospital, Rozzano, Milano (Italy); Marino, Carmelo [Humanitas Centro Catanese di Oncologia, Catania (Italy); Russo, Serenella [Azienda Sanitaria, Firenze (Italy); Stasi, Michele [Azienda Ospedaliera Ordine Mauriziano di Torino, Torino (Italy); Strigari, Lidia [Istituto Nazionale Tumori Regina Elena, Roma (Italy); Veronese, Ivan [Universita' degli Studi di Milano, Milano (Italy); Landoni, Valeria [Istituto Nazionale Tumori Regina Elena, Roma (Italy)

    2015-01-01

    The increasing use of moderate (<35 fractions) and extreme (<5 fractions) hypofractionated radiation therapy in prostate cancer is yielding favorable results, both in terms of maintained biochemical response and toxicity. Several hypofractionation (HF) schemes for the treatment of prostate cancer are available, although there is considerable variability in the techniques used to manage intra-/interfraction motion and deliver radiation doses. We performed a review of the published studies on HF regimens as a topic of interest for the Stereotactic Ablative Radiotherapy working group, which is part of the Italian Association of Medical Physics. Aspects of organ motion management (imaging for contouring, target volume definition, and rectum/bladder preparation) and treatment delivery (prostate localization, image guided radiation therapy strategy and frequency) were evaluated and categorized to assess outcome relative to disease control and toxicity. Despite the heterogeneity of the data, some interesting trends that emerged from the review might be useful in identifying an optimum HF strategy.

  9. Synergistic effect of ionizing radiation on chemical disinfectant treatments for reduction of natural microflora on seafood

    Science.gov (United States)

    Kim, Hyunjoo; Ha, Ji-Hyoung; Lee, Ju-Woon; Jo, Cheorun; Ha, Sang-Do

    2012-08-01

    The purpose of this study was to determine whether combined treatments would produce synergistic disinfection effects on seafood products such as mussel and squid compared with single treatments. We investigated the bactericidal effects of chlorine and ionizing radiation on the natural microflora of mussel and squid. Total aerobic bacteria initially ranged from 102 to 104 Log CFU/g. More than 100 ppm of chlorine and irradiation at 1 kGy were sufficient to reduce the total aerobic bacteria on mussel and squid to a level lower than detection limit (10 CFU/g). Synergistic effects against natural microflora were observed for all combined treatment. These results suggest that a significant synergistic benefit results from combine chlorine-ionizing radiation treatment against natural microflora on mussel and squid.

  10. Evaluation of stability using Monte Carlo Simulation in 2 people isolation treatment room of radiation iodine

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Dong Gun [Dept. of Nuclear Medicine, Dongnam Institute of Radiological and Medical Sciences Cancer center, Busan (Korea, Republic of); Ko, Sung Jin; KIm, Chang Soo; Kim, Jung Hoon [Dept. of Radiological Science, College of Health Sciences, Catholic University of Pusan, Busan (Korea, Republic of)

    2016-09-15

    Radioactive iodine treatment that uses the 2 people isolation room is to cause unnecessary radiation exposure between patients. This research is to be tested safety of 2 people Isolation treatment room and dose-rate through conservative perspective except physiology characteristic and biology information on the assumption that patient have iodine without excretion in 2 people isolation treatment room. This research shows that 364 keV gamma rays emitted by the radioiodine was to determine that the air layer about 30 cm or lead shield 3 mm a half-layer. In addition, In addition, patients in the distance, and lead shielding, length of hospital stay (48 hours) for external radiation exposure that is received from the other patients, two of treatment as appears to be lower than the legal isolation standard dose less than 5 mSv isolation room effective analyzed that manageable.

  11. In Vivo Imaging of Microglia Turnover in the Mouse Retina After Ionizing Radiation and Dexamethasone Treatment

    DEFF Research Database (Denmark)

    Alt, C.; Runnels, J. M.; Mortensen, L. J.;

    2014-01-01

    examine if anti-inflammatory treatment can mitigate the radiation-induced turnover of retinal microglia and the replacement by bone marrow-derived cells (BMDCs). METHODS. Two-color chimeric mice were generated by lethal irradiation of heterozygous CX3CR1-GFP mice that express GFP in microglial cells...... to the microglia loss, resulting in a transient depletion of the total immune cell number in the retina. With dexamethasone treatment, both the loss of the resident microglia and the infiltration of BMDCs were suppressed by at least 50%. CONCLUSIONS. Anti-inflammatory treatment with the corticosteroidal agent......PURPOSE. Gamma irradiation and bone marrow transplantation (BMT) are established clinical procedures for the treatment of hematologic malignancies. The radiation targets cells in the bone marrow, but injury to other tissues, including the central nervous system (CNS), have been reported. Here, we...

  12. 赋形波束共形天线口径综合与方向图分析%Analysis on Shaped-beam Aperture Synthesis and Radiation Patternof Conformal Antenna

    Institute of Scientific and Technical Information of China (English)

    张继浩; 王化宇; 李丽娴; 黄一; 章泉源

    2016-01-01

    In order to meet the special requirement of conformal antenna array,a novel shaped⁃beam aperture synthetic method of conformal antenna is proposed,the corresponding calculation and optimization results are provided.The Woodward and Chebyshev linear array synthetic methods are employed to obtain the planar array distribution,which is projected to the cylinder conformal array to achieve the required aperture distribution.The phase and amplitude errors are induced in the antenna elements,and the fabrication and experi⁃ment techniques are considered for error correction,which is valuable for antenna engineering design.The simulated radiation pattern indicates that the proposed method can be applied in shaped⁃beam and low sidelobe conformal aperture array.%针对工程领域对共形阵列天线波束的要求日渐特殊,给出了一种赋形波束共形天线口径的综合方法,以及相应的数值计算和优化结果。在直线阵的基础上结合Woodward综合理论和切比雪夫综合理论,并把综合结果通过投影口径综合法运用到柱面共形阵。将幅度与相位的误差引入各个天线单元通道中,同时考虑到现有加工试验手段对误差的修正,突出了本方法对天线工程设计的指导意义。仿真结果表明,用该方法可以综合常用波束形状和较低副瓣的共形天线口径。

  13. 宫颈癌根治术后三维适形放疗的临床价值%Clinical value of three-dimensional conformal radiation therapy for postoperation cervix cancer

    Institute of Scientific and Technical Information of China (English)

    Yaqin Qu; Yubao He; Xin Jiang; Zhiming Chen

    2008-01-01

    Objective:To observe the clinical value of three dimensional conformal radiation therapy (3D-CRT) followed by radical surgery and discuss the best radiation technique for cervical cancer patients after radical hysterectomy.Methods:From February 2003 to June 2006,115 stage Ⅰ-Ⅲa uterus cervix cancer patients received postoperation radiotherapy in our department after radical surgery.They were randomly divided into two groups.There were 81 patients in 3D-CRT group and 74 patients in traditional radiation group.According to FIGO,there were 45 in stage Ⅰ,77 in stage Ⅰa,31 in stage Ⅱb,2 in stage Ⅲa.Pathological examination confirmed that 148 cases had squamous carcinoma and 7 cases had adenocarcinoma.The target volume included supravaginal portion,the cervical stump,paracervical tissue,common iliac lymph nodes,internal and external iliac lymph nodes,obturator and sacral lymph nodes.For 3D-CRT group we designed four-field or two-fields rotating irradiation in the left-right and the anterior-posterior direction.For traditional radiation group we designed two-field,anterior-posterior,at opposed lateral directions.The radiation dose ranged from 48-50 Gy.Stage Ⅱb patients with a cervical stump recurrence received postoperative boost radiation by 8-10 Gy.Results:There were no significant difference in 0.5-year,1-year,1.5-year,2-year local control rate between 3D-CRT group and traditional radiation group (P>0.05).The occurrence of early and late complications was significant lower in 3D-CRT group than that in traditional radiation group (P<0.05).There was significant difference in gastrointestinal reaction and urinary system reaction between the two groups (P<0.05).In postoperation radiotherapy 3D-CRT was superior compared with traditional two-field radiation at opposed lateral direction.Conclusion:3D-CRT is superior compared with traditional radiation.Four-field rotating irradiation in 3D-CRT has advantages of dose focusing,even dose distribution and cause

  14. Development of a technique for environmental treatment by radiation

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Myun Joo; Jin, J. H.; Jung, Y. D. and others

    2000-04-01

    This study was carried out for the development of pilot plant which can produce industrial water from effluent of sewage treatment plant by irradiation. As a basic study, the characteristics on decomposition of organic compounds, decoloration and sterilization of bacteria were evaluated. An additive mainly composed by sponge type of TiO{sub 2} was developed for reduction of irradiation dose and enhancement of removal efficiency of organic compounds. The optimum pilot plant was composed of sysem with gamma irradiation/ozone/additive/ion exchange. The effluent with BOD 20 ppm, COD 25 ppm and color 25 ADMI could be treated to less than 5 ppm and 5 ADMI under the irradiation of 5 kGy. The disinfection of microorganism also could be done perfectively under the same irradiation. A small amount of heavy metal ions and inorganic ions, nitrogen, contained in effluent were removed by ion exchanger. From the operation of pilot plant it could be concluded that irradiation technique can be a good method for the produce of industrial water from effluent.

  15. Application of Hydrocyclone and UV Radiation as a Ballast Water Treatment Method

    Directory of Open Access Journals (Sweden)

    Željko Kurtela

    2010-05-01

    Full Text Available The ballast water exchange methods in open sea are, for the time being, the prevailing procedures accepted by shipowners. However, such methods do not guarantee full efficacy in elimination of allochthonous organisms. Besides, in some navigation zones, in particular in the closed seas, not even the criteria prescribed by international regulations can be fulfilled, i.e. the position of a ship exchanging ballast must be farther than 200Nm from the shore (alternatively 50Nm at the sea depth exceeding 200m. Numerous research attempts on various treatment methods lead to the conclusion that there is still no scientific opinion on the final choice of methods for wide application on board. The treatment methods, such as hydrocyclone separation in the first stage and UV radiation in the second stage, stand a good chance for application on board. Advantages of such a combined method are in the very application of treatment that can be performed during all stages of ballast water treatment, i.e. loading ballast, voyage in ballast and discharging ballast. In closed seas and on shorter routes the operational advantages of hydrocyclone and UV radiation could be the prevailing factor for application. Within the research on the possible application of ballast water treatment by hydrocyclone and UV radiation, a pilot plant with hydrocyclone cluster and UV device was constructed. The research carried out on the pilot plant installed on board the m/v ‘’Naše more’’ proved the effectiveness of such ballast water treatment method and offered a new approach in using hydrocyclone for the inactivation of organisms by hydrodynamic forces. This approach has largely increased the efficacy of the device and a new method for utilization of hydrocyclone in ballast water treatment on board has been discovered. KEY WORDS: ballast water treatment, hydrocyclone, UV radiation, application of method, pilot plant, hydrodynamic forces

  16. Successful radiation treatment of chylous ascites following pancreaticoduodenectomy

    Energy Technology Data Exchange (ETDEWEB)

    Corradini, Stefanie; Niemoeller, Olivier M. [University of Munich, Department of Radiation Oncology, Munich (Germany); Liebig, Sylke [Gemeinschaftspraxis Prof. Zwicker and Partner, Konstanz (Germany); Zwicker, Felix [Gemeinschaftspraxis Prof. Zwicker and Partner, Konstanz (Germany); German Cancer Research Center (DKFZ), Clinical Cooperation Unit Molecular and Radiation Oncology, Heidelberg (Germany); Lamade, Wolfram [Helios Privatklinik, Allgemein- and Viszeralchirurgie, Ueberlingen (Germany)

    2015-05-01

    Chylous ascites is a rare complication following pancreaticoduodenectomy. We report on a case of chylous ascites following pancreaticoduodenectomy in a 76-year-old patient diagnosed with pancreatic cancer. There are various known conservative management strategies, including dietary measures or total parenteral nutrition. Unfortunately, conservative treatment - with total parenteral nutrition and fasting over a period of 4 weeks - was not successful in the present case. The daily output volume of chylous ascites was up to 2500 ml/day. Based on clinical experiences with successfully treated lymphocutaneous fistulas, low-dose radiotherapy was initiated. External beam radiotherapy comprising a total dose of 8.0 Gy to the paraaortic lymph node region was administered in daily single fractions of 1.0 Gy (five fractions/week). Throughout the course of external beam radiotherapy, the secretion of abdominal ascites rapidly decreased, resulting in complete resolution after 2 weeks. There was no clinical evidence of chylous ascites on follow-up. As a result of this experience, we believe that external beam radiotherapy should be considered as an alternative therapy in refractory cases of chylous ascites. (orig.) [German] Das Chyloperitoneum ist eine seltene Komplikation nach Pankreatikoduodenektomie. Wir berichten ueber einen 76-jaehrigen Patienten mit Chyloperitoneum nach Resektion eines Pankreaskarzinoms. Die konservativen Therapiestrategien, wie beispielsweise diaetetische Massnahmen oder totale parenterale Ernaehrung, waren im vorliegenden Fall ueber einen Zeitraum von 4 Wochen nicht erfolgreich. Es bestand eine persistierende Sekretion von Chylaszites von bis zu 2500 ml/Tag. Basierend auf den klinischen Erfahrungen bei erfolgreich behandelten lymphokutanen Fisteln, wurde eine perkutane Radiotherapie eingeleitet. Die Bestrahlung des paraaortalen Lymphabflusses ueber ventrodorsale Gegenfelder wurde bis zu einer Gesamtdosis von 8,0 Gy in 1,0 Gy Einzeldosis (5 Fraktionen

  17. Treatment Guidelines for Preoperative Radiation Therapy for Retroperitoneal Sarcoma: Preliminary Consensus of an International Expert Panel

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, Elizabeth H., E-mail: ebaldini@partners.org [Department of Radiation Oncology, Dana-Farber Cancer Institute and Brigham and Women' s Hospital, Boston, Massachusetts (United States); Wang, Dian [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States); Haas, Rick L.M. [Department of Radiotherapy, The Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam (Netherlands); Catton, Charles N. [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Indelicato, Daniel J. [Department of Radiation Oncology, University of Florida Medical Center, Jacksonville, Florida (United States); Kirsch, David G. [Department of Radiation Oncology, Duke University Medical Center, Durham, North Carolina (United States); Roberge, David [Department of Radiation Oncology, Centre Hospitalier de l' Université de Montreal, Montreal, Quebec (Canada); Salerno, Kilian [Department of Radiation Oncology, Roswell Park Cancer Institute, Buffalo, New York (United States); Deville, Curtiland [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins Sidney Kimmel Cancer Center, Washington, DC (United States); Guadagnolo, B. Ashleigh [Department of Radiation Oncology, MD Anderson Cancer Center, Houston, Texas (United States); O' Sullivan, Brian [Department of Radiation Oncology, Princess Margaret Cancer Centre, Toronto, Ontario (Canada); Petersen, Ivy A. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Le Pechoux, Cecile [Department of Radiotherapy, Institut Gustave-Roussy, Villejuif (France); Abrams, Ross A. [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States); DeLaney, Thomas F. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States)

    2015-07-01

    Purpose: Evidence for external beam radiation therapy (RT) as part of treatment for retroperitoneal sarcoma (RPS) is limited. Preoperative RT is the subject of a current randomized trial, but the results will not be available for many years. In the meantime, many practitioners use preoperative RT for RPS, and although this approach is used in practice, there are no radiation treatment guidelines. An international expert panel was convened to develop consensus treatment guidelines for preoperative RT for RPS. Methods and Materials: An expert panel of 15 academic radiation oncologists who specialize in the treatment of sarcoma was assembled. A systematic review of reports related to RT for RPS, RT for extremity sarcoma, and RT-related toxicities for organs at risk was performed. Due to the paucity of high-quality published data on the subject of RT for RPS, consensus recommendations were based largely on expert opinion derived from clinical experience and extrapolation of relevant published reports. It is intended that these clinical practice guidelines be updated as pertinent data become available. Results: Treatment guidelines for preoperative RT for RPS are presented. Conclusions: An international panel of radiation oncologists who specialize in sarcoma reached consensus guidelines for preoperative RT for RPS. Many of the recommendations are based on expert opinion because of the absence of higher level evidence and, thus, are best regarded as preliminary. We emphasize that the role of preoperative RT for RPS has not been proven, and we await data from the European Organization for Research and Treatment of Cancer (EORTC) study of preoperative radiotherapy plus surgery versus surgery alone for patients with RPS. Further data are also anticipated pertaining to normal tissue dose constraints, particularly for bowel tolerance. Nonetheless, as we await these data, the guidelines herein can be used to establish treatment uniformity to aid future assessments of efficacy

  18. 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

  19. 21 CFR 579.40 - Ionizing radiation for the treatment of poultry feed and poultry feed ingredients.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Ionizing radiation for the treatment of poultry feed and poultry feed ingredients. 579.40 Section 579.40 Food and Drugs FOOD AND DRUG ADMINISTRATION... § 579.40 Ionizing radiation for the treatment of poultry feed and poultry feed ingredients....

  20. Radiation retinopathy secondary to treatment of maxillary sinus carcinoma: a dramatic case.

    Science.gov (United States)

    Galindo-Bocero, J; Macías-Franco, S; Sánchez-García, S; Fonollá-Gil, M; García-Alonso, A

    2017-10-01

    A 53-year old male presented with visual impairment in right eye after irradiation of right maxillary sinus carcinoma. Funduscopy shows radiation retinopathy: haemorrhages, exudates, macular oedema, and peripheral retinal ischaemia. A poor outcome was achieved despite laser treatment and intravitreal injections of bevacizumab, resulting in evisceration of the affected eye. Radiation retinopathy must be considered in any loss of vision after head and neck irradiation. Ophthalmological long-term follow-up of these patients is essential for an early diagnosis. Copyright © 2017 Sociedad Española de Oftalmología. Publicado por Elsevier España, S.L.U. All rights reserved.

  1. Effect of gamma radiation and endodontic treatment on mechanical properties of human and bovine root dentin

    Energy Technology Data Exchange (ETDEWEB)

    Novais, Veridiana Resende; Soares, Priscilla Barbosa Ferreira; Guimaraes, Carlla Martins; Schliebe, Lais Rani Sales Oliveira; Braga, Stella Sueli Lourenco; Soares, Carlos Jose, E-mail: carlosjsoares@ufu.br [Universidade Federal de Uberlandia (UFU), MG (Brazil)

    2016-11-15

    This study evaluated the effect of gamma radiation and endodontic treatment on the microhardness and flexural strength of human and bovine root dentin. Forty single rooted human teeth and forty bovine incisor teeth were collected, cleaned and stored in distilled water at 4 °C. The human and bovine teeth were divided into 4 groups (n=10) resulting from the combination of two study factors: first, regarding the endodontic treatment in 2 levels: with or without endodontic treatment; and second, radiotherapy in two levels: with or without radiotherapy by 60 Gy of Co-60 gamma radiation fractioned into 2 Gy daily doses five days per week. Each tooth was longitudinally sectioned in two parts; one-half was used for the three-point bending test and the other for the Knoop hardness test (KHN). Data were analyzed by 3-way ANOVA and Tukey HSD test (α=0.05). No significant difference was found for flexural strength values. The human dentin had significantly higher KHN than the bovine. The endodontic treatment and radiotherapy resulted in significantly lower KHN irrespective of tooth origin. The results indicated that the radiotherapy had deleterious effects on the microhardness of human and bovine dentin and this effect is increased by the interaction with endodontic therapy. The endodontic treatment adds additional negative effect on the mechanical properties of radiated tooth dentin; the restorative protocols should be designed taking into account this effect. (author)

  2. Emerging Role of MRI for Radiation Treatment Planning in Lung Cancer.

    Science.gov (United States)

    Cobben, David C P; de Boer, Hans C J; Tijssen, Rob H; Rutten, Emma G G M; van Vulpen, Marco; Peerlings, Jurgen; Troost, Esther G C; Hoffmann, Aswin L; van Lier, Astrid L H M W

    2016-12-01

    Magnetic resonance imaging (MRI) provides excellent soft-tissue contrast and allows for specific scanning sequences to optimize differentiation between various tissue types and properties. Moreover, it offers the potential for real-time motion imaging. This makes magnetic resonance imaging an ideal candidate imaging modality for radiation treatment planning in lung cancer. Although the number of clinical research protocols for the application of magnetic resonance imaging for lung cancer treatment is increasing (www.clinicaltrials.gov) and the magnetic resonance imaging sequences are becoming faster, there are still some technical challenges. This review describes the opportunities and challenges of magnetic resonance imaging for radiation treatment planning in lung cancer. © The Author(s) 2015.

  3. Photonuclear processes in the treatment room and patient during radiation therapy with 50 MV photons

    Energy Technology Data Exchange (ETDEWEB)

    Gudowska, Irena [Karolinska Inst., Stockholm (Sweden). Dept. of Radiation Physics

    1997-10-01

    The objectives of this project were to determine the level of photoneutron radiation around the MM50 Racetrack Microtron at Karolinska Hospital, operating in different modes and to evaluate the photonuclear absorbed dose to the treated volume during therapy with a 50 MV photon beam. The photoneutron radiation has been studied both using a {sup 235}U fission chamber and by computer simulation. The estimated neutron equivalent dose due to accelerator produced neutrons delivered to the tissues inside and outside the treatment volume do not exceed the recommended values. However, there is a potential risk that the sensitive tissues (lens of the eye and gonads), outside the treatment volume, can receive a dose of about 300-500 mSv per photon treatment course of 60 Gy with a slight increase for secondary malignancies. 47 refs, 15 figs, 6 tabs.

  4. Abdominal radiation - discharge

    Science.gov (United States)

    Radiation - abdomen - discharge; Cancer - abdominal radiation; Lymphoma - abdominal radiation ... When you have radiation treatment for cancer, your body goes through changes. About 2 weeks after radiation treatment starts, you might notice changes ...

  5. PET-Based Thoracic Radiation Oncology.

    Science.gov (United States)

    Simone, Charles B; Houshmand, Sina; Kalbasi, Anusha; Salavati, Ali; Alavi, Abass

    2016-07-01

    Fluorodeoxyglucose-PET is increasingly being integrated into multiple aspects of oncology. PET/computed tomography (PET/CT) has become especially important in radiation oncology. With the increasing use of advanced techniques like intensity-modulated radiation therapy and proton therapy, PET/CT scans have played critical roles in the target delineation of tumors for radiation oncologists delivering conformal treatment techniques. Use of PET/CT is well established in lung cancer and several other thoracic malignancies. This article details the current uses of PET/CT in thoracic radiation oncology with a focus on lung cancer and describes expected future roles of PET/CT for thoracic tumors.

  6. Stereotactic Radiosurgery and Fractionated Stereotactic Radiation Therapy for the Treatment of Uveal Melanoma.

    Science.gov (United States)

    Yazici, Gozde; Kiratli, Hayyam; Ozyigit, Gokhan; Sari, Sezin Yuce; Cengiz, Mustafa; Tarlan, Bercin; Mocan, Burce Ozgen; Zorlu, Faruk

    2017-05-01

    To evaluate treatment results of stereotactic radiosurgery or fractionated stereotactic radiation therapy (SRS/FSRT) for uveal melanoma. We retrospectively evaluated 181 patients with 182 uveal melanomas receiving SRS/FSRT between 2007 and 2013. Treatment was administered with CyberKnife. According to Collaborative Ocular Melanoma Study criteria, tumor size was small in 1%, medium in 49.5%, and large in 49.5% of the patients. Seventy-one tumors received treatment outcome was achieved using ≥45 Gy in 3 fractions. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. Orthovoltage radiation therapy treatment planning using Monte Carlo simulation: treatment of neuroendocrine carcinoma of the maxillary sinus

    Science.gov (United States)

    Gao, Wanbao; Raeside, David E.

    1997-12-01

    Dose distributions that result from treating a patient with orthovoltage beams are best determined with a treatment planning system that uses the Monte Carlo method, and such systems are not readily available. In the present work, the Monte Carlo method was used to develop a computer code for determining absorbed dose distributions in orthovoltage radiation therapy. The code was used in planning treatment of a patient with a neuroendocrine carcinoma of the maxillary sinus. Two lateral high-energy photon beams supplemented by an anterior orthovoltage photon beam were utilized in the treatment plan. For the clinical case and radiation beams considered, a reasonably uniform dose distribution TOP"/> is achieved within the target volume, while the dose to the lens of each eye is 4 - 8% of the prescribed dose. Therefore, an orthovoltage photon beam, when properly filtered and optimally combined with megavoltage beams, can be effective in the treatment of cancers below the skin, providing that accurate treatment planning is carried out to establish with accuracy and precision the doses to critical structures.

  8. Intensity-Modulated Radiation Therapy With Concurrent Chemotherapy as Preoperative Treatment for Localized Gastric Adenocarcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Chakravarty, Twisha; Crane, Christopher H. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Ajani, Jaffer A. [Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mansfield, Paul F. [Department of Surgical Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Briere, Tina M.; Beddar, A. Sam [Department of Radiation Physics, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Mok, Henry; Reed, Valerie K.; Krishnan, Sunil; Delclos, Marc E. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States); Das, Prajnan, E-mail: PrajDas@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, TX (United States)

    2012-06-01

    Purpose: The goal of this study was to evaluate dosimetric parameters, acute toxicity, pathologic response, and local control in patients treated with preoperative intensity-modulated radiation therapy (IMRT) and concurrent chemotherapy for localized gastric adenocarcinoma. Methods: Between November 2007 and April 2010, 25 patients with localized gastric adenocarcinoma were treated with induction chemotherapy, followed by preoperative IMRT and concurrent chemotherapy and, finally, surgical resection. The median radiation therapy dose was 45 Gy. Concurrent chemotherapy was 5-fluorouracil and oxaliplatin in 18 patients, capecitabine in 3, and other regimens in 4. Subsequently, resection was performed with total gastrectomy in 13 patients, subtotal gastrectomy in 7, and other surgeries in 5. Results: Target coverage, expressed as the ratio of the minimum dose received by 99% of the planning target volume to the prescribed dose, was a median of 0.97 (range, 0.92-1.01). The median V{sub 30} (percentage of volume receiving at least 30 Gy) for the liver was 26%; the median V{sub 20} (percentage of volume receiving at least 20 Gy) for the right and left kidneys was 14% and 24%, respectively; and the median V{sub 40} (percentage of volume receiving at least 40 Gy) for the heart was 18%. Grade 3 acute toxicity developed in 14 patients (56%), including dehydration in 10, nausea in 8, and anorexia in 5. Grade 4 acute toxicity did not develop in any patient. There were no significant differences in the rates of acute toxicity, hospitalization, or feeding tube use in comparison to those in a group of 50 patients treated with preoperative three-dimensional conformal radiation therapy with concurrent chemotherapy. R0 resection was obtained in 20 patients (80%), and pathologic complete response occurred in 5 (20%). Conclusions: Preoperative IMRT for gastric adenocarcinoma was well tolerated, accomplished excellent target coverage and normal structure sparing, and led to appropriate

  9. Experimental study of the impact of antimicrobial treatments on Campylobacter, Enterococcus and PCR-capillary electrophoresis single-strand conformation polymorphism profiles of the gut microbiota of chickens.

    Science.gov (United States)

    Mourand, Gwenaëlle; Jouy, Eric; Bougeard, Stéphanie; Dheilly, Alexandra; Kérouanton, Annaëlle; Zeitouni, Salman; Kempf, Isabelle

    2014-11-01

    An experiment was conducted to compare the impact of antimicrobial treatments on the susceptibility of Campylobacter, Enterococcus faecium and Enterococcus faecalis, and on the diversity of broiler microbiota. Specific-pathogen-free chickens were first orally inoculated with strains of Campylobacter and Enterococcus faecium. Birds were then orally treated with recommended doses of oxytetracycline, sulfadimethoxine/trimethoprim, amoxicillin or enrofloxacin. Faecal samples were collected before, during and after antimicrobial treatment. The susceptibility of Campylobacter, Enterococcus faecium and Enterococcus faecalis strains isolated on supplemented or non-supplemented media was studied and PCR-capillary electrophoresis single-strand conformation polymorphism (CE-SSCP) profiles of the gut microbiota were analysed. Enrofloxacin-resistant Campylobacter were selected in the enrofloxacin-treated group and showed the Thr86Ile mutation in the gyrA gene. Acquisition of the tetO gene in Campylobacter coli isolates was significantly more frequent in birds given oxytetracycline. No impact of amoxicillin treatment on the susceptibility of Campylobacter could be detected. Ampicillin- and sulfadimethoxine/trimethoprim-resistant Enterococcus faecium were selected in amoxicillin-treated broilers, but no selection of the inoculated vancomycin-resistant Enterococcus faecium could be detected, although it was also resistant to tetracycline and sulfadimethoxine/trimethoprim. PCR-CE-SSCP revealed significant variations in a few peaks in treated birds as compared with non-treated chickens. In conclusion, antimicrobial treatments perturbed chicken gut microbiota, and certain antimicrobial treatments selected or co-selected resistant strains of Campylobacter and Enterococcus.

  10. Treatment of radiation-induced hemorrhagic gastritis with prednisolone: A case report

    Institute of Scientific and Technical Information of China (English)

    Lan Zhang; Xiao-Ying Xie; Yan Wang; Yan-Hong Wang; Yi Chen; Zheng-Gang Ren

    2012-01-01

    Radiation-induced gastritis is an infrequent cause of gastrointestinal bleeding.It is a serious complication arising from radiation therapy,and the standard treatment method has not been established.The initial injury is characteristically acute inflammation of gastric mucosa.We presented a 46-year-old male patient with hemorrhagic gastritis induced by external radiotherapy for metastatic retroperitoneal lymph node of hepatocellular carcinoma.The endoscopic examination showed diffuse edematous hyperemicmucosa with telangiectasias in the whole muscosa of the stomach and duodenal bulb.Mlultiple hemorrhagic patches with active oozing were found over the antrum.Anti-secretary therapy was initiated for hemostasis,but melena still occurred off and on.Finally,he was successfully treated by prednisolone therapy.We therefore strongly argue in favor of perdnisolone therapy to effectively treat patients with radiation-induced hemorrhagic gastritis.

  11. SU-E-T-538: Lung SBRT Dosimetric Comparison of 3D Conformal and RapidArc Planning

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, R; Zhan, L; Osei, E [Grand River Hospital, Kitchener, ON (Canada)

    2015-06-15

    Purpose: Dose distributions of RapidArc Plan can be quite different from standard 3D conformal radiation therapy. SBRT plans can be optimized with high conformity or mimic the 3D conformal treatment planning with very high dose in the center of the tumor. This study quantifies the dosimetric differences among 3D conformal plan; flattened beam and FFF beam RapidArc Plans for lung SBRT. Methods: Five lung cancer patients treated with 3D non-coplanar SBRT were randomly selected. All the patients were CT scanned with 4DCT to determine the internal target volume. Abdominal compression was applied to minimize respiratory motion for SBRT patients. The prescription dose was 48 Gy in 4 fractions. The PTV coverage was optimized by two groups of objective function: one with high conformity, another mimicking 3D conformal dose distribution with high dose in the center of PTV. Optimization constraints were set to meet the criteria of the RTOG-0915 protocol. All VMAT plans were optimized with the RapidArc technique using four full arcs in Eclipse treatment planning system. The RapidArc SBRT plans with flattened 6MV beam and 6MV FFF beam were generated and dosimetric results were compared with the previous treated 3D non-coplanar plans. Results: All the RapidArc plans with flattened beam and FFF beam had similar results for the PTV and OARs. For the high conformity optimization group, The DVH of PTV exhibited a steep dose fall-off outside the PTV compared to the 3D non-coplanar plan. However, for the group mimicking the 3D conformal target dose distribution, although the PTV is very similar to the 3D conformal plan, the ITV coverage is better than 3D conformal plan. Conclusion: Due to excellent clinical experiences of 3D conformal SBRT treatment, the Rapid Arc optimization mimicking 3D conformal planning may be suggested for clinical use.

  12. Risk of second bone sarcoma following childhood cancer: role of radiation therapy treatment.

    Science.gov (United States)

    Schwartz, Boris; Benadjaoud, Mohamed Amine; Cléro, Enora; Haddy, Nadia; El-Fayech, Chiraz; Guibout, Catherine; Teinturier, Cécile; Oberlin, Odile; Veres, Cristina; Pacquement, Hélène; Munzer, Martine; N'guyen, Tan Dat; Bondiau, Pierre-Yves; Berchery, Delphine; Laprie, Anne; Hawkins, Mike; Winter, David; Lefkopoulos, Dimitri; Chavaudra, Jean; Rubino, Carole; Diallo, Ibrahima; Bénichou, Jacques; de Vathaire, Florent

    2014-05-01

    Bone sarcoma as a second malignancy is rare but highly fatal. The present knowledge about radiation-absorbed organ dose-response is insufficient to predict the risks induced by radiation therapy techniques. The objective of the present study was to assess the treatment-induced risk for bone sarcoma following a childhood cancer and particularly the related risk of radiotherapy. Therefore, a retrospective cohort of 4,171 survivors of a solid childhood cancer treated between 1942 and 1986 in France and Britain has been followed prospectively. We collected detailed information on treatments received during childhood cancer. Additionally, an innovative methodology has been developed to evaluate the dose-response relationship between bone sarcoma and radiation dose throughout this cohort. The median follow-up was 26 years, and 39 patients had developed bone sarcoma. It was found that the overall incidence was 45-fold higher [standardized incidence ratio 44.8, 95 % confidence interval (CI) 31.0-59.8] than expected from the general population, and the absolute excess risk was 35.1 per 100,000 person-years (95 % CI 24.0-47.1). The risk of bone sarcoma increased slowly up to a cumulative radiation organ absorbed dose of 15 Gy [hazard ratio (HR) = 8.2, 95 % CI 1.6-42.9] and then strongly increased for higher radiation doses (HR for 30 Gy or more 117.9, 95 % CI 36.5-380.6), compared with patients not treated with radiotherapy. A linear model with an excess relative risk per Gy of 1.77 (95 % CI 0.6213-5.935) provided a close fit to the data. These findings have important therapeutic implications: Lowering the radiation dose to the bones should reduce the incidence of secondary bone sarcomas. Other therapeutic solutions should be preferred to radiotherapy in bone sarcoma-sensitive areas.

  13. Treatment of small cell lung cancer with TRA-8 in combination with cisplatin and radiation.

    Science.gov (United States)

    Bonner, James A; Willey, Christopher D; Yang, Eddy S; Dobelbower, Michael C; Sanford, Leisa L; Bright, Sheila J; Buchsbaum, Donald J; Raisch, Kevin P

    2011-10-01

    Limited stage small cell lung cancer (SCLC) represents a minority of SCLC. Despite extensive clinical trials, standard treatment remains cisplatin-based chemotherapy and thoracic irradiation (TI). This study focused on the interaction of cisplatin/radiation with the anti-human DR5 monoclonal antibody TRA-8 in SCLC cells. TRA-8 binds specifically to DR5 and has been shown to activate apoptosis. Four human SCLC cell lines were utilized for experimentation (SCLC-41, SCLC-58, SCLC-68, and SCLC-74). Immunoblot analysis was used to determine relative protein levels of DR5, DR4 and pro-caspase 8 for each cell line. Using a tetrazolium-based assay (XTT), the IC(50) values for cisplatin with or without TRA-8 were determined for the SCLC cell lines. Four SCLC lines were assayed with a combination of TRA-8 (10 μg/ml), 2 Gy radiation and various concentrations of cisplatin. Apoptosis was evaluated using Annexin V-FITC and cleaved caspase immunoblotting. Using a SCLC-58 subcutaneous xenograft model, treatment began 21 d after tumor cell injection. Treatment included weekly cisplatin (4 mg/kg) and radiation of 1 Gy (24 h after cisplatin) and TRA-8 (200 μg) was administered i.p. twice weekly for three weeks. Immunoblot analysis showed similar levels of DR5 for all cell lines with variable levels of DR4. Various concentrations of TRA-8 antibody (≤ 10 μg/ml) induced no significant cytotoxicity in the SCLC cell lines. The in vitro combination treatment with TRA-8 (10 μg/ml), 1.25 μg/ml cisplatin and 2 Gy radiation showed increased cytotoxicity when compared to combinations without TRA-8. Furthermore, the triple combination demonstrated the greatest amount of apoptosis as measured by Annexin V staining. The in vivo studies showed the combination of 1G y, cisplatin and TRA-8 extended the tumor doubling time to 44 d as compared to any doublet treatment groups that ranged from 12 to 20 d. Analysis of survival data showed 100% of the combination group (RT+cisplatin+TRA-8) were

  14. Androgen Induces Adaptation to Oxidative Stress in Prostate Cancer: Implications for Treatment with Radiation Therapy

    Directory of Open Access Journals (Sweden)

    Jehonathan H. Pinthus

    2007-01-01

    Full Text Available Radiation therapy is a standard treatment for prostate cancer (PC. The postulated mechanism of action for radiation therapy is the generation of reactive oxygen species (ROS. Adjuvant androgen deprivation (AD therapy has been shown to confer a survival advantage over radiation alone in high-risk localized PC. However, the mechanism of this interaction is unclear. We hypothesize that androgens modify the radioresponsiveness of PC through the regulation of cellular oxidative homeostasis. Using androgen receptor (AR+ 22rv1 and AR− PC3 human PC cell lines, we demonstrated that testosterone increased basal reactive oxygen species (bROS levels, resulting in dose-dependent activation of phospho-p38 and pAKT, increased expression of clusterin, catalase, manganese superoxide dismutase. Similar data were obtained in three human PC xenografts; WISH-PC14, WISH-PC23, CWR22, growing in testosterone-supplemented or castrated SCID mice. These effects were reversible through AD or through incubation with a reducing agent. Moreover, testosterone increased the activity of catalase, superoxide dismutases, glutathione reductase. Consequently, AD significantly facilitated the response of AR+ cells to oxidative stress challenge. Thus, testosterone induces a preset cellular adaptation to radiation through the generation of elevated bROS, which is modified by AD. These findings provide a rational for combined hormonal and radiation therapy for localized PC.

  15. Exposure to Mobile Phone Radiation Opens New Horizons in Alzheimer’s Disease Treatment

    Science.gov (United States)

    Mortazavi, SAR; Shojaei-Fard, MB; Haghani, M; Shokrpour, N; Mortazavi, SMJ

    2013-01-01

    Alzheimer’s disease, the most common type of dementia and a progressive neurodegenerative disease, occurs when the nerve cells in the brain die. Although there are medications that can help delay the development of Alzheimer’s disease, there is currently no cure for this disease. Exposure to ionizing and non-ionizing radiation may cause adverse health effects such as cancer.  Looking at the other side of the coin, there are reports indicating stimulatory or beneficial effects after exposure to cell phone radiofrequency radiation. Mortazavi et al. have previously reported some beneficial cognitive effects such as decreased reaction time after human short-term exposure to cell phone radiation or occupational exposure to radar microwave radiation. On the other hand, some recent reports have indicated that RF radiation may have a role in protecting against cognitive impairment in Alzheimer’s disease. Although the majority of these data come from animal studies that cannot be easily extrapolated to humans, it can be concluded that this memory enhancing approach may open new horizons in treatment of cognitive impairment in Alzheimer disease. PMID:25505755

  16. Reply to 'Comment on genetic and global algorithms for optimization of three-dimensional conformal radiotherapy treatment planning'

    Energy Technology Data Exchange (ETDEWEB)

    Wu Xingen; Zhu Yunping [Department of Radiation Oncology, St. Jude Children' s Research Hospital, Memphis, TN (United States)

    2001-06-01

    In reply to the letter by Dr. Vaarkamp, we would like first to offer him our thank for pointing out some issues in the complex problem of radiotherapy planning optimization that will require our closer attention in the future. We certainly can add any organs at risk (OARs) to help improve the overall radiotherapy ratio. We can objectively judge the merit of our planning on the basis of the resulting dose volume histogram (DVH) information for certain OARs chosen on the basis of the tumour location and clinical decision. In addition, any treatment planning, regardless of the method used, must still be approved by the radiation oncologist. Response to the first comment: Different plans may select different OARs for different clinical considerations and patient outcomes. Our selection of OARs (left or right eye, thyroid or spinal cord) is based mainly on clinical judgement about the specific case under investigation. For example, the first case (Wu et al 2000) used three OARs (left eye, right eye and thyroid). In this clinical case, the radiation oncologist did not specify the volumes for hypothalamus, pituitary, optic chiasm an any auditory apparatus. That is not to say that these organs are not important. We think it is reasonable to choose the OARs according to clinical judgement, since it is very convenient for us to make a comparison with the manual plans where those DVHs are available. In the case of the right temporal lobe, for example, we look at it closely when we want to treat the right eye. But when the parotid gland is treated, the hypothalamus and pituitary are normally no problem, because few beams go directly through them. We are aware of all the OARs mentioned by Dr. Vaarkamp and can take any or all of them into consideration in our planning optimization. We can also apply relative weighting to them. We are working on a model that will not only limit the maximum dose in OARs but also take the DVHs of these OARs into consideration in our optimization

  17. Preoperative, intraoperative, and postoperative radiation in the treatment of primary soft tissue sarcoma.

    Science.gov (United States)

    Suit, H D; Mankin, H J; Wood, W C; Proppe, K H

    1985-06-01

    The rationale for combining radiation with conservative surgery in the treatment of sarcoma of soft tissue is discussed, as well as the advantages for performing the radiation preoperatively on the one hand and postoperatively on the other. The results of treatment of soft tissue sarcoma by radical resectional surgery or amputation in 464 patients at four centers and by conservative surgery, and postoperative radiation in 416 patients at three centers, have been reviewed. The local failure rates were 18.1% and 18.3%, respectively. The results obtained by radiation administered postoperatively (110 patients) or preoperatively (60 patients) at the Massachusetts General Hospital during the period September 1971 to August 1982 are analyzed and discussed with reference to 5-year actuarial local control and survival results as well as causes of failure with respect to AJC stage, histologic type, anatomic site, and size of tumor. The results which have been obtained by the preoperative approach are judged to be superior, particularly for the larger lesions and higher grades that predominated in that group. Of a total of 170 patients, there were 19 local failures; 13 of these were diagnosed at the time when metastatic disease was not evident. Of those 13, 12 have been subjected to salvage surgery and 7 remain with no evidence of disease at 1 to 3.5 years after the salvage procedure. A major problem in the management of these patients remains the occult metastatic disease.

  18. Radiation Therapy

    Science.gov (United States)

    Radiation therapy is a cancer treatment. It uses high doses of radiation to kill cancer cells and stop them from ... half of all cancer patients receive it. The radiation may be external, from special machines, or internal, ...

  19. Implications of a high-definition multileaf collimator (HD-MLC on treatment planning techniques for stereotactic body radiation therapy (SBRT: a planning study

    Directory of Open Access Journals (Sweden)

    Chen Yiyi

    2009-07-01

    Full Text Available Abstract Purpose To assess the impact of two multileaf collimator (MLC systems (2.5 and 5 mm leaf widths on three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, and dynamic conformal arc techniques for stereotactic body radiation therapy (SBRT of liver and lung lesions. Methods Twenty-nine SBRT plans of primary liver (n = 11 and lung (n = 18 tumors were the basis of this study. Five-millimeter leaf width 120-leaf Varian Millennium (M120 MLC-based plans served as reference, and were designed using static conformal beams (3DCRT, sliding-window intensity-modulated beams (IMRT, or dynamic conformal arcs (DCA. Reference plans were either re-optimized or recomputed, with identical planning parameters, for a 2.5-mm width 120-leaf BrainLAB/Varian high-definition (HD120 MLC system. Dose computation was based on the anisotropic analytical algorithm (AAA, Varian Medical Systems with tissue heterogeneity taken into account. Each plan was normalized such that 100% of the prescription dose covered 95% of the planning target volume (PTV. Isodose distributions and dose-volume histograms (DVHs were computed and plans were evaluated with respect to target coverage criteria, normal tissue sparing criteria, as well as treatment efficiency. Results Dosimetric differences achieved using M120 and the HD120 MLC planning were generally small. Dose conformality improved in 51.7%, 62.1% and 55.2% of the IMRT, 3DCRT and DCA cases, respectively, with use of the HD120 MLC system. Dose heterogeneity increased in 75.9%, 51.7%, and 55.2% of the IMRT, 3DCRT and DCA cases, respectively, with use of the HD120 MLC system. DVH curves demonstrated a decreased volume of normal tissue irradiated to the lower (90%, 50% and 25% isodose levels with the HD120 MLC. Conclusion Data derived from the present comparative assessment suggest dosimetric merit of the high definition MLC system over the millennium MLC system. However, the clinical significance of these results

  20. The peer review system (PRS) for quality assurance and treatment improvement in radiation therapy

    Science.gov (United States)

    Le, Anh H. T.; Kapoor, Rishabh; Palta, Jatinder R.

    2012-02-01

    Peer reviews are needed across all disciplines of medicine to address complex medical challenges in disease care, medical safety, insurance coverage handling, and public safety. Radiation therapy utilizes technologically advanced imaging for treatment planning, often with excellent efficacy. Since planning data requirements are substantial, patients are at risk for repeat diagnostic procedures or suboptimal therapeutic intervention due to a lack of knowledge regarding previous treatments. The Peer Review System (PRS) will make this critical radiation therapy information readily available on demand via Web technology. The PRS system has been developed with current Web technology, .NET framework, and in-house DICOM library. With the advantages of Web server-client architecture, including IIS web server, SOAP Web Services and Silverlight for the client side, the patient data can be visualized through web browser and distributed across multiple locations by the local area network and Internet. This PRS will significantly improve the quality, safety, and accessibility, of treatment plans in cancer therapy. Furthermore, the secure Web-based PRS with DICOM-RT compliance will provide flexible utilities for organization, sorting, and retrieval of imaging studies and treatment plans to optimize the patient treatment and ultimately improve patient safety and treatment quality.

  1. A suspected case of radiation induced-cancer 13 years after initial treatment for tongue cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nakashima, Mikio; Ozeki, Satoru; Oobu, Kazunari; Ohishi, Masamichi; Matsuo, Kou [Kyushu Univ., Fukuoka (Japan). Faculty of Dentistry

    1996-06-01

    A suspected case of radiation-induced cancer 13 years after initial treatment for tongue cancer was reported. The patient was a 61-year-old female, treated by 60 Gy radiotherapy for tongue cancer of the right side. Seven years later, recurrent tongue tumor arose and was irradiated up to the total dosage of 82.5 Gy. Thirteen years after the initial treatment, a tumor arose near the flap resembling a mucocele at first, and its growth was rapid. She underwent surgery in 1993. Histopathological examination revealed partial mesenchymal features, but it was difficult to determine its origin. Based on Sakai`s criteria, the points of location, latency, and histopathological observation, the tumor was considered to be radiation-induced cancer. (author)

  2. Application of mass spectrometry based electronic nose and chemometrics for fingerprinting radiation treatment

    Science.gov (United States)

    Gupta, Sumit; Variyar, Prasad S.; Sharma, Arun

    2015-01-01

    Volatile compounds were isolated from apples and grapes employing solid phase micro extraction (SPME) and subsequently analyzed by GC/MS equipped with a transfer line without stationary phase. Single peak obtained was integrated to obtain total mass spectrum of the volatile fraction of samples. A data matrix having relative abundance of all mass-to-charge ratios was subjected to principal component analysis (PCA) and linear discriminant analysis (LDA) to identify radiation treatment. PCA results suggested that there is sufficient variability between control and irradiated samples to build classification models based on supervised techniques. LDA successfully aided in segregating control from irradiated samples at all doses (0.1, 0.25, 0.5, 1.0, 1.5, 2.0 kGy). SPME-MS with chemometrics was successfully demonstrated as simple screening method for radiation treatment.

  3. Is argon plasma coagulation an effective and safe treatment option for patients with chronic radiation proctitis after high doses of radiotherapy?

    Directory of Open Access Journals (Sweden)

    Eduardo Hortelano

    Full Text Available Introduction: In severe cases refractory to medical treatment, APC appears to be the preferred alternative to control persistent rectal bleeding of patients with chronic radiation proctitis. Although successful outcomes have been demonstrated in patients previously treated with moderate doses of radiotherapy, there is reluctance towards its indication due to the concern of severe adverse events in patients treated with high doses of radiation. Objectives: The aim of this study was to assess the efficacy and toxicity of APC in the management of bleeding radiation-induced proctitis in patients treated with high doses of radiation for prostate cancer. Methods and materials: Data from 30 patients were treated with APC due to chronic radiation proctitis, were reviewed retrospectively. All cases had prostate cancer and 9 of them (30 % underwent previous radical prostatectomy. The median dose of conformal 3D External Beam Radiotherapy (EBRT delivered was 74 Gy (range 46-76. Median rectal D1cc and D2cc was 72.5 and 72.4 Gy respectively. Median rectal V70, V60 and V40 was 12, 39.5 and 80 %. Cardiovascular and digestive disease, diabetes, smoking behaviour, lowest haemoglobin and transfusion requirements were recorded. Indications for treatment with APC were anemia and persistent bleeding despite medical treatment. Argon gas flow was set at 1.8 l/min with an electrical power setting of 50 W. Results: Median age of all patients was 69.6 years. The median lowest haemoglobin level was 9.6 g/dL. Median time between completion of radiotherapy and first session of APC was 13 months. Ninety-four therapeutic sessions were performed (median 3 sessions. Median time follow-up was 14.5 months (range 2-61. Complete response with resolved rectal bleeding was achieved in 23 patients (77 %, partial response in 5 (16 % and no control in 2 (6 %. No patients required transfusion following therapy. Two patients developed long-term (> 6 weeks grade 2 rectal ulceration and

  4. Conformal transformations and conformal invariance in gravitation

    CERN Document Server

    Dabrowski, Mariusz P; Blaschke, David B

    2008-01-01

    Conformal transformations are frequently used tools in order to study relations between various theories of gravity and Einstein relativity. Because of that, in this paper we discuss the rules of conformal transformations for geometric quantities in general relativity. In particular, we discuss the conformal transformations of the matter energy-momentum tensor. We thoroughly discuss the latter and show the subtlety of the conservation law (i.e., the geometrical Bianchi identity) imposed in one of the conformal frames in reference to the other. The subtlety refers to the fact that conformal transformation ``creates'' an extra matter term composed of the conformal factor which enters the conservation law. In an extreme case of the flat original spacetime the matter is ``created'' due to work done by the conformal transformation to bend the spacetime which was originally flat. We also discuss how to construct the conformally invariant gravity which, in the simplest version, is a special case of the Brans-Dicke t...

  5. Dosimetric benefits of IMRT and VMAT in the treatment of middle thoracic esophageal cancer: is the conformal radiotherapy still an alternative option?

    Science.gov (United States)

    Wu, Zhiqin; Xie, Congying; Hu, Meilong; Han, Ce; Yi, Jinling; Zhou, Yongqiang; Yuan, Huawei; Jin, Xiance

    2014-05-08

    The purpose of this study is to investigate the dosimetric differences among conformal radiotherapy (CRT), intensity-modulated radiotherapy (IMRT), and volumetric-modulated radiotherapy (VMAT) in the treatment of middle thoracic esophageal cancer, and determine the most appropriate treatment modality. IMRT and one-arc VMAT plans were generated for eight middle thoracic esophageal cancer patients treated previous with CRT. The planning target volume (PTV) coverage and protections on organs at risk of three planning schemes were compared. All plans have sufficient PTV coverage and no significant differences were observed, except for the conformity and homogeneity. The lung V5, V10, and V13 in CRT were 47.9% ± 6.1%, 36.5% ± 4.6%, and 33.2% ± 4.2%, respectively, which were greatly increased to 78.2% ± 13.7% (p VMAT, respectively. The lung V20 (p = 0.03) in VMAT and the V30 (p = 0.04) in IMRT were lower than those in CRT. Both IMRT and VMAT achieved a better protection on heart. However, the volumes of the healthy tissue outside of PTV irradiated by a low dose were higher for IMRT and VMAT. IMRT and VMAT also had a higher MU, optimization time, and delivery time compared to CRT. In conclusion, all CRT, IMRT, and VMAT plans are able to meet the prescription and there is no clear distinction on PTV coverage. IMRT and VMAT can only decrease the volume of lung and heart receiving a high dose, but at a cost of delivering low dose to more volume of lung and normal tissues. CRT is still a feasible option for middle thoracic esophageal cancer radiotherapy, especially for the cost-effective consideration.

  6. Stereotactic body radiation therapy for the primary treatment of localized prostate cancer

    OpenAIRE

    Oliai, Caspian; Lanciano, Rachelle; Sprandio, Brian; Yang, Jun; Lamond, John; Arrigo, Steven; Good, Michael; Mooreville, Michael; Garber, Bruce; Brady, Luther W.

    2012-01-01

    Objective The low alpha/beta ratio of prostate cancer suggests that hypofractionated schemes of dose-escalated radiotherapy should be advantageous. We report our experience using stereotactic body radiation therapy (SBRT) for the primary treatment of prostate cancer to assess efficacy and toxicity. Methods From 2007 to 2010, 70 patients (51 % low risk, 31 % intermediate risk, and 17 % high risk) with localized prostate cancer were treated with SBRT using the CyberKnife system. One-third of pa...

  7. Two Cases of Post-Radiation Sarcoma after Breast Cancer Treatment

    OpenAIRE

    Noh, Jae Myoung; Huh, Seung Jae; Choi, Doo Ho; Park, Won; Nam, Seok Jin

    2012-01-01

    We describe two cases of post-radiation sarcoma after breast cancer treatment. The first patient was a 61-year-old woman who underwent partial mastectomy of the right breast and adjuvant whole breast irradiation 7 years previously. Subsequently, a rapidly growing mass from the anterior arc of the right fifth rib was incidentally detected on an abdomino-pelvic computed tomography scan. The second patient was a 70-year-old woman who received neoadjuvant chemotherapy and a partial mastectomy of ...

  8. Hodgkin lymphoma: Evolution and dilemma in radiation treatments; Evolution et dilemmes dans les traitements du lymphome de Hodgkin

    Energy Technology Data Exchange (ETDEWEB)

    Girinsky, T.; Ghalibafian, M.; Paumier, A. [Institut Gustave-Roussy, Dept. des Radiations, 94 - Villejuif (France); Ghalibafian, M. [Hopital Marak, Dept. des radiations, Teheran (Iran, Islamic Republic of)

    2009-10-15

    Multiple new developments in the treatments of patients with Hodgkin lymphoma have occurred in the last 10 years. Radiation treatments have become extremely precise in localized Hodgkin lymphomas, on the other hand, they have almost completely disappeared in advanced stages. For patients with refractory or recurrent disease, it is strongly advocated, whenever feasible, to deliver a mantle field radiation treatment after an autologous stem cell transplant to avoid any further recurrence of the disease. (authors)

  9. Argon beam coagulation for treatment of symptomatic radiation-induced proctitis.

    Science.gov (United States)

    Fantin, A C; Binek, J; Suter, W R; Meyenberger, C

    1999-04-01

    Radiation proctitis is a complication of radiotherapy for malignant pelvic disease. Argon beam coagulation is a new and rapidly evolving technology that permits a "no-touch" electrocoagulation of diseased tissue. We analyzed retrospectively the records of 7 patients with prostatic and endometrial cancers treated with irrradiation (median radiation dose was 6840 cGy, range 2400 to 7200 cGy). The median time to onset of symptoms after the conclusion of radiotherapy was 20 months (range 16 to 48 months); symptoms consisted of rectal bleeding and tenesmus in all patients. The patients underwent argon beam coagulation after colonoscopic evaluation. The usual treatment interval was 3 weeks (range 1 to 3 weeks). A median of 2 treatment sessions (range 2 to 4) was necessary for complete symptom relief. All interventions were well tolerated without complications. During follow-up (median 24 months, range 18 to 24 months), there was no recurrence of symptoms (bleeding, tenesmus). Argon beam coagulation is a safe, well tolerated, and effective treatment option in symptomatic radiation proctitis.

  10. Radiation-induced bowel injury: the impact of radiotherapy on survivorship after treatment for gynaecological cancers

    Science.gov (United States)

    Kuku, S; Fragkos, C; McCormack, M; Forbes, A

    2013-01-01

    Background: The number of women surviving cancer who live with symptoms of bowel toxicity affecting their quality of life continues to rise. In this retrospective study, we sought to describe and analyse the presenting clinical features in our cohort, and evaluate possible predictors of severity and chronicity in women with radiation-induced bowel injury after treatment for cervical and endometrial cancers. Methods: Review of records of 541 women treated within the North London Gynaecological Cancer Network between 2003 and 2010 with radiotherapy with or without chemotherapy for cervical and endometrial cancer identified 152 women who reported significant new bowel symptoms after pelvic radiation. Results: Factor analysis showed that the 14 most common and important presenting symptoms could be ‘clustered' into 3 groups with predictive significance for chronicity and severity of disease. Median follow-up for all patients was 60 months. Univariate analysis showed increasing age, smoking, extended field radiation, cervical cancer treatment and the need for surgical intervention to be significant predictors for severity of ongoing disease at last follow-up. On multivariate analysis, only age, cancer type (cervix) and symptom combinations/‘cluster' of (bloating, flatulence, urgency, rectal bleeding and per-rectal mucus) were found to be significant predictors of disease severity. Fifteen (19%) women in the cervical cancer group had radiation-induced bowel injury requiring surgical intervention compared with five (6.7%) in the endometrial cancer group. Conclusion: Women with cervical cancer are younger and appear to suffer more severe symptoms of late bowel toxicity, whereas women treated for endometrial cancer suffer milder more chronic disease. The impact of radiation-induced bowel injury and the effect on cancer survivorship warrants further research into investigation of predictors of severe late toxicity. There is a need for prospective trials to aid early

  11. Radiation absorbed dose measurement after I-131 metaiodobenzylguanidine treatment in a patient with pheochromycytoma

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Won Il; Kim, Byeung Il; Lee, Jae Sung; Lee, Jung Rim; Choi, Chang Woon; Lim, Sang Moo; Hong, Sung Woon [Korea Cancer Center, Seoul (Korea, Republic of)

    1999-08-01

    The measurement of radiation absorbed dose is useful to predict the response after I-131 labeled metaiodobenzylguanidine (MIBG) therapy and determine therapy dose in patients with unresectable or malignant pheochromocytoma. We estimated the absorbed dose in tumor tissue after high dose I-131 MIBG in a patient with pheochromocytoma using a gamma camera and Medical Internal Radiation Dose (MIRD) formula. A 64-year old female patient with pheochromocytoma who had multiple metastases of mediastinum, right kidney and periaortic lymph nodes, received 74 GBq (200 mCi) of K-131 MIBG. We obtained anterior and posterior images at 0.5, 16, 24, 64 and 145 hours after treatment. Two standard sources of 37 and 74 MBq of I-131 were imaged simulatanously. Cummulated I-131 MIBG uptake in tumor tissue was calculated after the correction of background activity, attenuation, system sensitivity and count loss at a high count rate. The calculated absorbed radiation dose was 32-63 Gy/ 74 GBq, which was lower than the known dose for tumor remission (150-200 Gy). Follow-up studies at 1 month showed minimally reduced tumor size on computed tomography, and mildly reduced I-131 MIBG uptake. We estimated radiation absorbed dose after therapeutic I-131 MIBG using a gamma camera and MIRD formula, which can be peformed in a clinical nuclear medicine laboratory. Our results suggest that the measurement of radiation absorbed dose in I-131 MIBG therapy is feasible as a routine clinical practice that can guide further treatment plan. The accuracy of dose measurement and correlation with clinical outcome should be evaluated further.

  12. [Stereotactic radiation therapy].

    Science.gov (United States)

    Aristu, J J; Ciérvide, R; Guridi, J; Moreno, M; Arbea, L; Azcona, J D; Ramos, L I; Zubieta, J L

    2009-01-01

    Stereotactic radiotherapy is a form of external radiotherapy that employs a system of three dimensional coordinates independent of the patient for the precise localisation of the lesion. It also has the characteristic that the radiation beams are conformed and precise, and converge on the lesion, making it possible to administer very high doses of radiotherapy without increasing the radiation to healthy adjacent organs or structures. When the procedure is carried out in one treatment session it is termed radiosurgery, and when administered over several sessions it is termed stereotactic radiotherapy. Special systems of fixing or immobilising the patient (guides or stereotactic frames) are required together with radiotherapy devices capable of generating conformed beams (lineal accelerator, gammaknife, cyberknife, tomotherapy, cyclotrons). Modern stereotactic radiotherapy employs intra-tumoural radio-opaque frames or CAT image systems included in the irradiation device, which make possible a precise localisation of mobile lesions in each treatment session. Besides, technological advances make it possible to coordinate the lesion's movements in breathing with the radiotherapy unit (gating and tracking) for maximum tightening of margins and excluding a greater volume of healthy tissue. Radiosurgery is mainly indicated in benign or malign cerebral lesions less than 3-4 centimetres (arteriovenous malformations, neurinomas, meningiomas, cerebral metastases) and stereotactic radiotherapy is basically administered in tumours of extracraneal localisation that require high conforming and precision, such as inoperable early lung cancer and hepatic metastasis.

  13. Conformal isoparametric hypersurfaces with two distinct conformal principal curvatures in conformal space

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The conformal geometry of regular hypersurfaces in the conformal space is studied.We classify all the conformal isoparametric hypersurfaces with two distinct conformal principal curvatures in the conformal space up to conformal equivalence.

  14. MO-B-BRB-03: Systems Engineering Tools for Treatment Planning Process Optimization in Radiation Medicine

    Energy Technology Data Exchange (ETDEWEB)

    Kapur, A. [Long Island Jewish Medical Center (United States)

    2015-06-15

    The radiotherapy treatment planning process has evolved over the years with innovations in treatment planning, treatment delivery and imaging systems. Treatment modality and simulation technologies are also rapidly improving and affecting the planning process. For example, Image-guided-radiation-therapy has been widely adopted for patient setup, leading to margin reduction and isocenter repositioning after simulation. Stereotactic Body radiation therapy (SBRT) and Radiosurgery (SRS) have gradually become the standard of care for many treatment sites, which demand a higher throughput for the treatment plans even if the number of treatments per day remains the same. Finally, simulation, planning and treatment are traditionally sequential events. However, with emerging adaptive radiotherapy, they are becoming more tightly intertwined, leading to iterative processes. Enhanced efficiency of planning is therefore becoming more critical and poses serious challenge to the treatment planning process; Lean Six Sigma approaches are being utilized increasingly to balance the competing needs for speed and quality. In this symposium we will discuss the treatment planning process and illustrate effective techniques for managing workflow. Topics will include: Planning techniques: (a) beam placement, (b) dose optimization, (c) plan evaluation (d) export to RVS. Planning workflow: (a) import images, (b) Image fusion, (c) contouring, (d) plan approval (e) plan check (f) chart check, (g) sequential and iterative process Influence of upstream and downstream operations: (a) simulation, (b) immobilization, (c) motion management, (d) QA, (e) IGRT, (f) Treatment delivery, (g) SBRT/SRS (h) adaptive planning Reduction of delay between planning steps with Lean systems due to (a) communication, (b) limited resource, (b) contour, (c) plan approval, (d) treatment. Optimizing planning processes: (a) contour validation (b) consistent planning protocol, (c) protocol/template sharing, (d) semi

  15. Physics strategies for sparing neural stem cells during whole-brain radiation treatments

    Energy Technology Data Exchange (ETDEWEB)

    Kirby, Neil; Chuang, Cynthia; Pouliot, Jean; Hwang, Andrew; Barani, Igor J. [Department of Radiation Oncology, University of California San Francisco, San Francisco, California 94143-1708 (United States)

    2011-10-15

    Purpose: Currently, there are no successful long-term treatments or preventive strategies for radiation-induced cognitive impairments, and only a few possibilities have been suggested. One such approach involves reducing the dose to neural stem cell compartments (within and outside of the hippocampus) during whole-brain radiation treatments for brain metastases. This study investigates the fundamental physics issues associated with the sparing of neural stem cells during photon radiotherapy for brain metastases. Methods: Several factors influence the stem cell dose: intracranial scattering, collimator leakage, beam energy, and total number of beams. The relative importance of these factors is investigated through a set of radiation therapy plans, which are all variations of an initial 6 MV intensity-modulated radiation therapy (IMRT) plan designed to simultaneously deliver a whole-brain dose of 30 Gy and maximally reduce stem cell compartment dose. Additionally, an in-house leaf segmentation algorithm was developed that utilizes jaw motion to minimize the collimator leakage. Results: The plans are all normalized such that 50% of the PTV receives 30 Gy. For the initial 6 MV IMRT plan, 50% of the stem cells receive a dose greater than 6.3 Gy. Calculations indicate that 3.6 Gy of this dose originates from intracranial scattering. The jaw-tracking segmentation algorithm, used in conjunction with direct machine parameter optimization, reduces the 50% stem cell dose to 4.3 and 3.7 Gy for 6 and 10 MV treatment beams, respectively. Conclusions: Intracranial scattering alone is responsible for a large dose contribution to the stem cell compartment. It is, therefore, important to minimize other contributing factors, particularly the collimator leakage, to maximally reduce dose to these critical structures. The use of collimator jaw tracking in conjunction with modern collimators can minimize this leakage.

  16. Treatment Effects and Sequelae of Radiation Therapy for Orbital Mucosa-Associated Lymphoid Tissue Lymphoma

    Energy Technology Data Exchange (ETDEWEB)

    Hata, Masaharu, E-mail: mhata@syd.odn.ne.jp [Department of Radiology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa (Japan); Omura, Motoko; Koike, Izumi [Department of Radiology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa (Japan); Tomita, Naoto [Department of Internal Medicine and Clinical Immunology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa (Japan); Iijima, Yasuhito [Department of Ophthalmology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa (Japan); Tayama, Yoshibumi; Odagiri, Kazumasa; Minagawa, Yumiko [Department of Radiology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa (Japan); Ogino, Ichiro [Department of Radiation Oncology, Yokohama City University Medical Center, Yokohama, Kanagawa (Japan); Inoue, Tomio [Department of Radiology, Yokohama City University Graduate School of Medicine, Yokohama, Kanagawa (Japan)

    2011-12-01

    Purpose: Among extranodal lymphomas, orbital mucosa-associated lymphoid tissue (MALT) lymphoma is a relatively rare presentation. We performed a review to ascertain treatment efficacy and toxicity of radiation therapy for orbital MALT lymphoma. We also evaluated changes in visual acuity after irradiation. Methods and Materials: Thirty patients with orbital MALT lymphoma underwent radiation therapy with curative intent. Clinical stages at diagnosis were stage I{sub E}A in 29 patients and stage II{sub E}A in 1 patient. Total doses of 28.8 to 45.8 Gy (median, 30 Gy) in 15 to 26 fractions (median, 16 fractions) were delivered to the tumors. Results: All irradiated tumors were controlled during the follow-up period of 2 to 157 months (median, 35 months) after treatment. Two patients had relapses that arose in the cervical lymph node and the ipsilateral palpebral conjunctiva outside the radiation field at 15 and 67 months after treatment, respectively. The 5-year local progression-free and relapse-free rates were 100% and 96%, respectively. All 30 patients are presently alive; the overall and relapse-free survival rates at 5 years were 100% and 96%, respectively. Although 5 patients developed cataracts of grade 2 at 8 to 45 months after irradiation, they underwent intraocular lens implantation, and their eyesight recovered. Additionally, there was no marked deterioration in the visual acuity of patients due to irradiation, with the exception of cataracts. No therapy-related toxicity of grade 3 or greater was observed. Conclusions: Radiation therapy was effective and safe for patients with orbital MALT lymphoma. Although some patients developed cataracts after irradiation, visual acuity was well preserved.

  17. Correcting radiation survey data to account for increased leakage during intensity modulated radiotherapy treatments

    Energy Technology Data Exchange (ETDEWEB)

    Kairn, T. [Premion Cancer Care, Wesley Medical Centre, Suite 1, 40 Chasely St, Auchenflower Qld 4066, Australia and Science and Engineering Faculty, Queensland University of Technology, G.P.O. Box 2434, Brisbane Qld 4000 (Australia); Crowe, S. B.; Trapp, J. V. [Science and Engineering Faculty, Queensland University of Technology, G.P.O. Box 2434, Brisbane Qld 4000 (Australia)

    2013-11-15

    Purpose: Intensity modulated radiotherapy (IMRT) treatments require more beam-on time and produce more linac head leakage to deliver similar doses to conventional, unmodulated, radiotherapy treatments. It is necessary to take this increased leakage into account when evaluating the results of radiation surveys around bunkers that are, or will be, used for IMRT. The recommended procedure of applying a monitor-unit based workload correction factor to secondary barrier survey measurements, to account for this increased leakage when evaluating radiation survey measurements around IMRT bunkers, can lead to potentially costly overestimation of the required barrier thickness. This study aims to provide initial guidance on the validity of reducing the value of the correction factor when applied to different radiation barriers (primary barriers, doors, maze walls, and other walls) by evaluating three different bunker designs.Methods: Radiation survey measurements of primary, scattered, and leakage radiation were obtained at each of five survey points around each of three different radiotherapy bunkers and the contribution of leakage to the total measured radiation dose at each point was evaluated. Measurements at each survey point were made with the linac gantry set to 12 equidistant positions from 0° to 330°, to assess the effects of radiation beam direction on the results.Results: For all three bunker designs, less than 0.5% of dose measured at and alongside the primary barriers, less than 25% of the dose measured outside the bunker doors and up to 100% of the dose measured outside other secondary barriers was found to be caused by linac head leakage.Conclusions: Results of this study suggest that IMRT workload corrections are unnecessary, for survey measurements made at and alongside primary barriers. Use of reduced IMRT workload correction factors is recommended when evaluating survey measurements around a bunker door, provided that a subset of the measurements used in

  18. Evaluation of planning dose accuracy in case of radiation treatment on inhomogeneous organ structure

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Chan Yong; Lee, Jae Hee; Kwak, Yong Kook; Ha, Min Yong [Dept. of Radiation Oncology, Seoul National University Hospital, Seoul (Korea, Republic of)

    2013-09-15

    We are to find out the difference of calculated dose of treatment planning system (TPS) and measured dose in case of inhomogeneous organ structure. Inhomogeneous phantom is made with solid water phantom and cork plate. CT image of inhomogeneous phantom is acquired. Treatment plan is made with TPS (Pinnacle3 9.2. Royal Philips Electronics, Netherlands) and calculated dose of point of interest is acquired. Treatment plan was delivered in the inhomogeneous phantom by ARTISTE (Siemens AG, Germany) measured dose of each point of interest is obtained with Gafchromic EBT2 film (International Specialty Products, US) in the gap between solid water phantom or cork plate. To simulate lung cancer radiation treatment, artificial tumor target of paraffin is inserted in the cork volume of inhomogeneous phantom. Calculated dose and measured dose are acquired as above. In case of inhomogeneous phantom experiment, dose difference of calculated dose and measured dose is about -8.5% at solid water phantom-cork gap and about -7% lower in measured dose at cork-solid water phantom gap. In case of inhomogeneous phantom inserted paraffin target experiment, dose difference is about 5% lower in measured dose at cork-paraffin gap. There is no significant difference at same material gap in both experiments. Radiation dose at the gap between two organs with different electron density is significantly lower than calculated dose with TPS. Therefore, we must be aware of dose calculation error in TPS and great care is suggested in case of radiation treatment planning on inhomogeneous organ structure.

  19. SU-E-J-267: Change in Mean CT Intensity of Lung Tumors During Radiation Treatment

    Energy Technology Data Exchange (ETDEWEB)

    Mahon, R; Tennyson, N; Weiss, E; Hugo, G [Virginia Commonwealth University, Richmond, VA (United States)

    2015-06-15

    Purpose: To evaluate CT intensity change of lung tumors during radiation therapy. Methods: Repeated 4D CT images were acquired on a CT simulator during the course of therapy for 27 lung cancer patients on IRB approved protocols. All subjects received definitive radiation treatment ± chemotherapy. CT scans were completed prior to treatment, and 2–7 times during the treatment course. Primary tumor was delineated by an experienced Radiation Oncologist. Contours were thresholded between −100 HU and 200 HU to remove airways and bone. Correlations between the change in the mean tumor intensity and initial tumor intensity, SUVmax, and tumor volume change rate were investigated. Reproducibility was assessed by evaluating the variation in mean intensity over all phases in 4DCT, for a subgroup of 19 subjects. Results: Reproducibility of tumor intensity between phases as characterized by the root mean square of standard deviation across 19 subjects was 1.8 HU. Subjects had a mean initial tumor intensity of 16.5 ± 11.6 HU and an overall reduction in HU by 10.3 ± 8.5 HU. Evaluation of the changes in tumor intensity during treatment showed a decrease of 0.3 ± 0.3 HU/day for all subjects, except three. No significant correlation was found between change in HU/day and initial HU intensity (p=0.53), initial PET SUVmax (p=0.69), or initial tumor volume (p=0.70). The rate of tumor volume change was weakly correlated (R{sup 2}=0.05) with HU change (p=0.01). Conclusion: Most lung cancer subjects showed a marked trend of decreasing mean tumor CT intensity throughout radiotherapy, including early in the treatment course. Change in HU/day is not correlated with other potential early predictors for response, such as SUV and tumor volume change. This Result supports future studies to evaluate change in tumor intensity on CT as an early predictor of response.

  20. Acutely exacerbated hypertension and increased inflammatory signs due to radiation treatment for metastatic pheochromocytoma

    Energy Technology Data Exchange (ETDEWEB)

    Teno, Shinichi; Tanabe, Akiyo; Nomura, Kaoru; Demura, Hiroshi [Tokyo Women`s Medical Coll. (Japan)

    1996-10-01

    Hypertension and norepinephrine hypersecretion in a 59-year-old woman suffering from malignant pheochromocytoma with multiple metastases were appropriately controlled with {alpha}- and {beta}- blockers, and {alpha}-methyltyrosine ({alpha}-MT), a catecholamine-synthesis inhibitor. Metastasized vertebrae were treated with external radiation to relieve pain, but this treatment had to be interrupted at a total dose of 20 Gy because the patient suffered acutely exacerbated hypertension (200/110 mmHg), tachycardia (160 beats/min) and a low-grade fever. Simultaneously her serum levels of LDH, potassium, urea nitrogen, creatinine, white blood cell count, CRP and norepinephrine were significantly increased, suggesting that this episode was due to radiation-induced tissue destruction and the leakage of catecholamines and possibly interleukin-6, a cytokine mediating inflammation which is reportedly present in pheochromocytoma. The marked hypertension was controlled by continuous iv administration of phentolamine and propranolol. Although radiation therapy effectively relieves pain due to neoplasmic metastasis to the bone, physicians should be aware that life-threatening complications such as the above occur in malignant pheochromocytoma. Sufficient pretreatment with adrenergic blocking agents and/or {alpha}-MT and careful monitoring of the patient`s general condition during radiation therapy, even at a low dose, are highly recommended. (author)

  1. SU-E-T-208: Incidence Cancer Risk From the Radiation Treatment for Acoustic Neuroma Patient

    Energy Technology Data Exchange (ETDEWEB)

    Kim, D [Kyung Hee University International Med. Serv., Seoul (Korea, Republic of); Chung, W [Kyung Hee University Hospital at Gangdong, Seoul, Seoul (Korea, Republic of); Shin, D [Kyung Hee University Hospital, Seoul, Seoul (Korea, Republic of); Yoon, M [Korea University, Seoul (Korea, Republic of)

    2014-06-01

    Purpose: The present study aimed to compare the incidence risk of a secondary cancer from therapeutic doses in patients receiving intensitymodulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT), and stereotactic radiosurgery (SRS). Methods: Four acoustic neuroma patients were treated with IMRT, VMAT, or SRS. Their incidnece excess relative risk (ERR), excess absolute risk (EAR), and lifetime attributable risk (LAR) were estimated using the corresponding therapeutic doses measured at various organs by radio-photoluminescence glass dosimeters (RPLGD) placed inside a humanoid phantom. Results: When a prescription dose was delivered in the planning target volume of the 4 patients, the average organ equivalent doses (OED) at the thyroid, lung, normal liver, colon, bladder, prostate (or ovary), and rectum were measured. The OED decreased as the distance from the primary beam increased. The thyroid received the highest OED compared to other organs. A LAR were estimated that more than 0.03% of AN patients would get radiation-induced cancer. Conclusion: The tyroid was highest radiation-induced cancer risk after radiation treatment for AN. We found that LAR can be increased by the transmitted dose from the primary beam. No modality-specific difference in radiation-induced cancer risk was observed in our study.

  2. Efficiency of Stereotactic Conformal Radiotherapy in Lung Metastases with Active Breathing Control

    Directory of Open Access Journals (Sweden)

    Olga Yu. Anikeeva, PhD

    2013-06-01

    Full Text Available Twenty four patients with lung metastases underwent radiosurgery treatment between October 2010 and December 2012. Stereotactic conformal high-dose radiation therapy with Active Breathing Control (ABC was conducted using the volumetric modulated arc therapy (VMAT technique. The median overall follow-up was 18 months (range 6-24 months, overall survival was 75%, and local control rate was 92%. The median time to progression was 4 months (range 1-18 months.There have been no cases of leucopenia, radiation esophagitis, mediastinitis or severe acute radiation pneumonitis. The late radiation effects Grade 2, according to the LENT SOMA scales, was observed in one patient (4%. The results of this study indicate that the usage of the stereotactic high-dose radiation therapy with ABC is safe and effective in the treatment of lung metastases.

  3. Dosimetric Comparison of Three-Dimensional Conformal Proton Radiotherapy, Intensity-Modulated Proton Therapy, and Intensity-Modulated Radiotherapy for Treatment of Pediatric Craniopharyngiomas

    Energy Technology Data Exchange (ETDEWEB)

    Boehling, Nicholas S. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Grosshans, David R., E-mail: dgrossha@mdanderson.org [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Bluett, Jaques B. [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Palmer, Matthew T. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Song, Xiaofei; Amos, Richard A.; Sahoo, Narayan [Department of Radiation Physics, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States); Meyer, Jeffrey J.; Mahajan, Anita; Woo, Shiao Y. [Department of Radiation Oncology, University of Texas M. D. Anderson Cancer Center, Houston, TX (United States)

    2012-02-01

    Purpose: Cranial irradiation in pediatric patients is associated with serious long-term adverse effects. We sought to determine whether both three-dimensional conformal proton radiotherapy (3D-PRT) and intensity-modulated proton therapy (IMPT) compared with intensity-modulated radiotherapy (IMRT) decrease integral dose to brain areas known to harbor neuronal stem cells, major blood vessels, and other normal brain structures for pediatric patients with craniopharyngiomas. Methods and Materials: IMRT, forward planned, passive scattering proton, and IMPT plans were generated and optimized for 10 pediatric patients. The dose was 50.4 Gy (or cobalt Gy equivalent) delivered in 28 fractions with the requirement for planning target volume (PTV) coverage of 95% or better. Integral dose data were calculated from differential dose-volume histograms. Results: The PTV target coverage was adequate for all modalities. IMRT and IMPT yielded the most conformal plans in comparison to 3D-PRT. Compared with IMRT, 3D-PRT and IMPT plans had a relative reduction of integral dose to the hippocampus (3D-PRT, 20.4; IMPT, 51.3%{sup Asterisk-Operator }), dentate gyrus (27.3, 75.0%{sup Asterisk-Operator }), and subventricular zone (4.5, 57.8%{sup Asterisk-Operator }). Vascular organs at risk also had reduced integral dose with the use of proton therapy (anterior cerebral arteries, 33.3{sup Asterisk-Operator }, 100.0%{sup Asterisk-Operator }; middle cerebral arteries, 25.9%{sup Asterisk-Operator }, 100%{sup Asterisk-Operator }; anterior communicating arteries, 30.8{sup Asterisk-Operator }, 41.7%{sup Asterisk-Operator }; and carotid arteries, 51.5{sup Asterisk-Operator }, 77.6{sup Asterisk-Operator }). Relative reduction of integral dose to the infratentorial brain (190.7{sup Asterisk-Operator }, 109.7%{sup Asterisk-Operator }), supratentorial brain without PTV (9.6, 26.8%{sup Asterisk-Operator }), brainstem (45.6, 22.4%{sup Asterisk-Operator }), and whole brain without PTV (19.4{sup Asterisk

  4. Acquired Tumor Cell Radiation Resistance at the Treatment Site Is Mediated Through Radiation-Orchestrated Intercellular Communication

    Energy Technology Data Exchange (ETDEWEB)

    Aravindan, Natarajan, E-mail: naravind@ouhsc.edu [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Aravindan, Sheeja; Pandian, Vijayabaskar; Khan, Faizan H.; Ramraj, Satish Kumar; Natt, Praveen [Department of Radiation Oncology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma (United States); Natarajan, Mohan [Department of Pathology, The University of Texas Health Science Center at San Antonio, San Antonio, Texas (United States)

    2014-03-01

    Purpose: Radiation resistance induced in cancer cells that survive after radiation therapy (RT) could be associated with increased radiation protection, limiting the therapeutic benefit of radiation. Herein we investigated the sequential mechanistic molecular orchestration involved in radiation-induced radiation protection in tumor cells. Results: Radiation, both in the low-dose irradiation (LDIR) range (10, 50, or 100 cGy) or at a higher, challenge dose IR (CDIR), 4 Gy, induced dose-dependent and sustained NFκB-DNA binding activity. However, a robust and consistent increase was seen in CDIR-induced NFκB activity, decreased DNA fragmentation, apoptosis, and cytotoxicity and attenuation of CDIR-inhibited clonal expansion when the cells were primed with LDIR prior to challenge dose. Furthermore, NFκB manipulation studies with small interfering RNA (siRNA) silencing or p50/p65 overexpression unveiled the influence of LDIR-activated NFκB in regulating CDIR-induced DNA fragmentation and apoptosis. LDIR significantly increased the transactivation/translation of the radiation-responsive factors tumor necrosis factor-α (TNF-α), interleukin-1α (IL-1α), cMYC, and SOD2. Coculture experiments exhibit LDIR-influenced radiation protection and increases in cellular expression, secretion, and activation of radiation-responsive molecules in bystander cells. Individual gene-silencing approach with siRNAs coupled with coculture studies showed the influence of LDIR-modulated TNF-α, IL-1α, cMYC, and SOD2 in induced radiation protection in bystander cells. NFκB inhibition/overexpression studies coupled with coculture experiments demonstrated that TNF-α, IL-1α, cMYC, and SOD2 are selectively regulated by LDIR-induced NFκB. Conclusions: Together, these data strongly suggest that scattered LDIR-induced NFκB-dependent TNF-α, IL-1α, cMYC, and SOD2 mediate radiation protection to the subsequent challenge dose in tumor cells.

  5. Optimization of Heart Block in the Left-sided Whole Breast Radiation Treatments

    Directory of Open Access Journals (Sweden)

    Ning Jeff Yue

    2014-12-01

    Full Text Available Purpose: Blocks have been used to protect heart from potential radiation damage in left-sided breast treatments. Since cardiac motion pattern may not be fully captured on conventional 3DCT or 4DCT simulation scans, this study was intended to investigate the optimization of the heart block design taking the cardiac motion into consideration.Materials and Methods: Whole breast treatment plans using two opposed tangential fields were designed based on 4DCT simulation images for 10 left-sided breast cancer patients. Using an OBI system equipped to a Varian Linac, beam-eye viewed fluoroscopy images were acquired for each of the treatment beams after patient treatment setup, and the MLC heart blocks were overlaid onto the fluoroscopy images with an in-house software package. A non-rigid image registration and tracking algorithm was utilized to track the cardiac motion on the fluoroscopy images with minimal manual delineation for initialization, and the tracked cardiac motion information was used to optimize the heart block design to minimize the radiation damage to heart while avoiding the over-shielding that may lead to underdosing certain breast tissues. Results: Twenty-three sets of fluoroscopy images were acquired on 23 different days of treatment for the 10 patients. As expected, heart moved under the influences of both respiratory and cardiac motion. It was observed that for 16 out of the 23 treatments heart moved beyond the planed heart block into treatment fields and MLC had to be adjusted to fully block heart. The adjustment was made for all but one patient. The number of the adjusted MLC leaves ranged from 1 to 16 (mean = 10, and the MLC leaf position adjustment ranged from 2 mm to 10 mm (mean = 6 mm. The added heart block areas ranged from 3 mm2 to 1230 mm2 (mean = 331 mm2. Conclusion: In left-sided whole breast radiation treatments, simulation CT (and 4DCT based heart block design may not provide adequate heart protection for all the

  6. Long-term results and complications of preoperative radiation in the treatment of rectal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Reed, W.P.; Garb, J.L.; Park, W.C.; Stark, A.J.; Chabot, J.R.; Friedmann, P.

    1988-02-01

    A retrospective study of 149 patients with rectal cancer diagnosed between 1972 and 1979 was undertaken to compare survival, disease-free survival, recurrence sites, and long-term complications of 40 patients who received 4000 to 4500 rads of preoperative adjuvant radiotherapy (radiation group) with those of 109 patients treated by resection alone (control group). After a mean follow-up of 84 months and 99 months, respectively, survival of the irradiated patients was significantly better than that of controls (68% versus 52%, p less than 0.05). Disease-free survival of those patients rendered free of disease by treatment was also superior for the irradiated group (84% versus 57%, p less than 0.005). Local recurrence without signs of distant metastases developed only one-third as often in irradiated patients (6% versus 18%). Distant metastases, alone or in combination with local recurrence, were also less common after radiation (12% versus 27%). Second primary tumors developed in 15% and 10% of the respective groups, a difference that was not statistically significant. When we consider the survival benefit of preoperative radiation therapy, long-term complications were relatively mild. Delayed healing of the perineum was noted in two irradiated patients. Persistent diarrhea was severe enough to warrant treatment in only one case, and one patient required a colostomy for intestinal obstruction from pelvic fibrosis.

  7. Successful treatment of a case of extensive radiation burns with multiple organ dysfunction syndrome.

    Science.gov (United States)

    Li, Yeyang; Wang, Jinlun; Li, Gang; Lin, Weihua; Li, Xiaojian; Tong, Renlian

    2013-01-01

    A patient sustained acute third-degree radiation burns over 41% of his body surface. The burns were due to occupational injury caused by an electron accelerator. Most of his wounds appeared and spread gradually during the 10th week after the radiation burn. Subsequently, severe wound infection with methicillin-resistant Staphylococcus aureus, severe pneumonia, respiratory failure, systemic inflammatory response syndrome, nephropathy, and hypoproteinemia had developed 3 months after the radiation injury. Most of the skin grafts could neither survive nor spread on the fresh wound after removing the necrotic tissue. This phenomenon resulted in many more wounds after operations, increasing the risk of wound infection. Parenteral nutrition, respiratory support with a ventilator, antibiotics for methicillin-resistant Staphylococcus aureus, steroid therapeutics for nephropathy, deeper debridement for wounds, and skin grafting were applied for treatment of this patient. The patient recovered gradually and was discharged from the hospital in good condition after 18 months. The authors suggest that deeper excision of necrotic tissue and skin grafting as well as appropriate antibiotics are principal measures to counteract systemic inflammatory response syndrome. Sufficient albumen by vein and steroid should be administered for treatment against nephropathy and for control of infection. Functions of organs should be carefully monitored to fine-tune the therapeutic programs and to minimize complications of organs.

  8. [Evaluation of Radiation Dose during Stent-graft Treatment Using a Hybrid Operating Room System].

    Science.gov (United States)

    Haga, Yoshihiro; Chida, Kouichi; Kaga, Yuji; Saitou, Kazuhisa; Arai, Takeshi; Suzuki, Shinichi; Iwaya, Yoshimi; Kumasaka, Eriko; Kataoka, Nozomi; Satou, Naoto; Abe, Mitsuya

    2015-12-01

    In recent years, aortic aneurysm treatment with stent graft grafting in the X-ray fluoroscopy is increasing. This is an endovascular therapy, because it is a treatment which includes the risk of radiation damage, having to deal with radiation damage, to know in advance is important. In this study, in order to grasp the trend of exposure stent graft implantation in a hybrid operating room (OR) system, focusing on clinical data (entrance skin dose and fluoroscopy time), was to count the total. In TEVAR and EVAR, fluoroscopy time became 13.40 ± 7.27 minutes, 23.67 ± 11.76 minutes, ESD became 0.87 ± 0.41 mGy, 1.11 ± 0.57 mGy. (fluoroscopy time of EVAR was 2.0 times than TEVAR. DAP of EVAR was 1.2 times than TEVAR.) When using the device, adapted lesions and usage are different. This means that care changes in exposure-related factors. In this study, exposure trends of the stent graft implantation was able to grasp. It can be a helpful way to reduce/optimize the radiation dose in a hybrid OR system.

  9. A surrogate-based metaheuristic global search method for beam angle selection in radiation treatment planning

    Science.gov (United States)

    Zhang, H. H.; Gao, S.; Chen, W.; Shi, L.; D'Souza, W. D.; Meyer, R. R.

    2013-03-01

    An important element of radiation treatment planning for cancer therapy is the selection of beam angles (out of all possible coplanar and non-coplanar angles in relation to the patient) in order to maximize the delivery of radiation to the tumor site and minimize radiation damage to nearby organs-at-risk. This category of combinatorial optimization problem is particularly difficult because direct evaluation of the quality of treatment corresponding to any proposed selection of beams requires the solution of a large-scale dose optimization problem involving many thousands of variables that represent doses delivered to volume elements (voxels) in the patient. However, if the quality of angle sets can be accurately estimated without expensive computation, a large number of angle sets can be considered, increasing the likelihood of identifying a very high quality set. Using a computationally efficient surrogate beam set evaluation procedure based on single-beam data extracted from plans employing equally-spaced beams (eplans), we have developed a global search metaheuristic process based on the nested partitions framework for this combinatorial optimization problem. The surrogate scoring mechanism allows us to assess thousands of beam set samples within a clinically acceptable time frame. Tests on difficult clinical cases demonstrate that the beam sets obtained via our method are of superior quality.

  10. Hafnium-doped hydroxyapatite nanoparticles with ionizing radiation for lung cancer treatment.

    Science.gov (United States)

    Chen, Min-Hua; Hanagata, Nobutaka; Ikoma, Toshiyuki; Huang, Jian-Yuan; Li, Keng-Yuan; Lin, Chun-Pin; Lin, Feng-Huei

    2016-06-01

    Recently, photodynamic therapy (PDT) is one of the new clinical options by generating cytotoxic reactive oxygen species (ROS) to kill cancer cells. However, the optical approach of PDT is limited by tissue penetration depth of visible light. In this study, we propose that a ROS-enhanced nanoparticle, hafnium-doped hydroxyapatite (Hf:HAp), which is a material to yield large quantities of ROS inside the cells when the nanoparticles are bombarded with high penetrating power of ionizing radiation. Hf:HAp nanoparticles are generated by wet chemical precipitation with total doping concentration of 15mol% Hf(4+) relative to Ca(2+) in HAp host material. The results show that the HAp particles could be successfully doped with Hf ions, resulted in the formation of nano-sized rod-like shape and with pH-dependent solubility. The impact of ionizing radiation on Hf:HAp nanoparticles is assessed by using in-vitro and in-vivo model using A549 cell line. The 2',7'-dichlorofluorescein diacetate (DCFH-DA) results reveal that after being exposed to gamma rays, Hf:HAp could significantly lead to the formation of ROS in cells. Both cell viability (WST-1) and cytotoxicity (LDH) assay show the consistent results that A549 lung cancer cell lines are damaged with changes in the cells' ROS level. The in-vivo studies further demonstrate that the tumor growth is inhibited owing to the cells apoptosis when Hf:HAp nanoparticles are bombarded with ionizing radiation. This finding offer a new therapeutic method of interacting with ionizing radiation and demonstrate the potential of Hf:HAp nanoparticles in tumor treatment, such as being used in a palliative treatment after lung surgical procedure. Photodynamic therapy (PDT) is one of the new clinical options by generating cytotoxic reactive oxygen species (ROS) to kill cancer cells. Unfortunately, the approach of PDT is usually limited to the treatment of systemic disease and deeper tumor, due to the limited tissue penetration depth of visible

  11. On the importance of prompt oxygen changes for hypofractionated radiation treatments

    Science.gov (United States)

    Kissick, Michael; Campos, David; van der Kogel, Albert; Kimple, Randall

    2013-10-01

    This discussion is motivated by observations of prompt oxygen changes occurring prior to a significant number of cancer cells dying (permanently stopping their metabolic activity) from therapeutic agents like large doses of ionizing radiation. Such changes must be from changes in the vasculature that supplies the tissue or from the metabolic changes in the tissue itself. An adapted linear-quadratic treatment is used to estimate the cell survival variation magnitudes from repair and reoxygenation from a two-fraction treatment in which the second fraction would happen prior to significant cell death from the first fraction, in the large fraction limit. It is clear the effects of oxygen changes are likely to be the most significant factor for hypofractionation because of large radiation doses. It is a larger effect than repair. Optimal dose timing should be determined by the peak oxygen timing. A call is made to prioritize near real time measurements of oxygen dynamics in tumors undergoing hypofractionated treatments in order to make these treatments adaptable and patient-specific.

  12. Efficacy and safety of far infrared radiation in lymphedema treatment: clinical evaluation and laboratory analysis.

    Science.gov (United States)

    Li, Ke; Zhang, Zheng; Liu, Ning Fei; Feng, Shao Qing; Tong, Yun; Zhang, Ju Fang; Constantinides, Joannis; Lazzeri, Davide; Grassetti, Luca; Nicoli, Fabio; Zhang, Yi Xin

    2017-01-26

    Swelling is the most common symptom of extremities lymphedema. Clinical evaluation and laboratory analysis were conducted after far infrared radiation (FIR) treatment on the main four components of lymphedema: fluid, fat, protein, and hyaluronan. Far infrared radiation is a kind of hyperthermia therapy with several and additional benefits as well as promoting microcirculation flow and improving collateral lymph circumfluence. Although FIR therapy has been applied for several years on thousands of lymphedema patients, there are still few studies that have reported the biological effects of FIR on lymphatic tissue. In this research, we investigate the effects of far infrared rays on the major components of lymphatic tissue. Then, we explore the effectiveness and safety of FIR as a promising treatment modality of lymphedema. A total of 32 patients affected by lymphedema in stage II and III were treated between January 2015 and January 2016 at our department. After therapy, a significant decrease of limb circumference measurements was noted and improving of quality of life was registered. Laboratory examination showed the treatment can also decrease the deposition of fluid, fat, hyaluronan, and protein, improving the swelling condition. We believe FIR treatment could be considered as both an alternative monotherapy and a useful adjunctive to the conservative or surgical lymphedema procedures. Furthermore, the real and significant biological effects of FIR represent possible future applications in wide range of the medical field.

  13. Impact of Boost Radiation in the Treatment of Ductal Carcinoma In Situ: A Population-Based Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Rakovitch, Eileen, E-mail: Eileen.rakovitch@sunnybrook.ca [Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario (Canada); Institute for Clinical Evaluative Sciences, Toronto, Ontario (Canada); University of Toronto, Toronto, Ontario (Canada); Narod, Steven A. [University of Toronto, Toronto, Ontario (Canada); Women’s College Research Institute, Toronto, Ontario (Canada); Nofech-Moses, Sharon; Hanna, Wedad [Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario (Canada); University of Toronto, Toronto, Ontario (Canada); Thiruchelvam, Deva; Saskin, Refik; Taylor, Carole [Institute for Clinical Evaluative Sciences, Toronto, Ontario (Canada); Tuck, Alan [London Health Sciences Center, London, Ontario (Canada); Youngson, Bruce; Miller, Naomi; Done, Susan J. [University Health Network, Toronto, Ontario (Canada); Sengupta, Sandip [Kingston General Hospital, Kingston, Ontario (Canada); Elavathil, Leela [University of Toronto, Toronto, Ontario (Canada); Henderson General Hospital, 711 Concession Street, Hamilton, Ontario (Canada); Jani, Prashant A. [University of Toronto, Toronto, Ontario (Canada); Regional Health Sciences Centre, Thunder Bay, Ontario (Canada); Bonin, Michel [Sudbury Regional Hospital, Sudbury, Ontario (Canada); Metcalfe, Stephanie [Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario (Canada); Paszat, Lawrence [Sunnybrook Health Sciences Centre, 2075 Bayview Avenue, Toronto, Ontario (Canada); Institute for Clinical Evaluative Sciences, Toronto, Ontario (Canada); University of Toronto, Toronto, Ontario (Canada)

    2013-07-01

    Purpose: To report the outcomes of a population of women with ductal carcinoma in situ (DCIS) treated with breast-conserving surgery and radiation and to evaluate the independent effect of boost radiation on the development of local recurrence. Methods and Materials: All women diagnosed with DCIS and treated with breast-conserving surgery and radiation therapy in Ontario from 1994 to 2003 were identified. Treatments and outcomes were identified through administrative databases and validated by chart review. The impact of boost radiation on the development of local recurrence was determined using survival analyses. Results: We identified 1895 cases of DCIS that were treated by breast-conserving surgery and radiation therapy; 561 patients received boost radiation. The cumulative 10-year rate of local recurrence was 13% for women who received boost radiation and 12% for those who did not (P=.3). The 10-year local recurrence-free survival (LRFS) rate among women who did and who did not receive boost radiation was 88% and 87%, respectively (P=.27), 94% and 93% for invasive LRFS (P=.58), and was 95% and 93% for DCIS LRFS (P=.31). On multivariable analyses, boost radiation was not associated with a lower risk of local recurrence (hazard ratio = 0.82, 95% confidence interval 0.59-1.15) (P=.25). Conclusions: Among a population of women treated with breast-conserving surgery and radiation for DCIS, additional (boost) radiation was not associated with a lower risk of local or invasive recurrence.

  14. SU-C-19A-05: Treatment Chairs for Modern Radiation Therapy Treatments<