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Sample records for target volumes based

  1. A local contrast based approach to threshold segmentation for PET target volume delineation

    International Nuclear Information System (INIS)

    Drever, Laura; Robinson, Don M.; McEwan, Alexander; Roa, Wilson

    2006-01-01

    Current radiation therapy techniques, such as intensity modulated radiation therapy and three-dimensional conformal radiotherapy rely on the precise delivery of high doses of radiation to well-defined volumes. CT, the imaging modality that is most commonly used to determine treatment volumes cannot, however, easily distinguish between cancerous and normal tissue. The ability of positron emission tomography (PET) to more readily differentiate between malignant and healthy tissues has generated great interest in using PET images to delineate target volumes for radiation treatment planning. At present the accurate geometric delineation of tumor volumes is a subject open to considerable interpretation. The possibility of using a local contrast based approach to threshold segmentation to accurately delineate PET target cross sections is investigated using well-defined cylindrical and spherical volumes. Contrast levels which yield correct volumetric quantification are found to be a function of the activity concentration ratio between target and background, target size, and slice location. Possibilities for clinical implementation are explored along with the limits posed by this form of segmentation

  2. Automated mediastinal lymph node detection from CT volumes based on intensity targeted radial structure tensor analysis.

    Science.gov (United States)

    Oda, Hirohisa; Bhatia, Kanwal K; Oda, Masahiro; Kitasaka, Takayuki; Iwano, Shingo; Homma, Hirotoshi; Takabatake, Hirotsugu; Mori, Masaki; Natori, Hiroshi; Schnabel, Julia A; Mori, Kensaku

    2017-10-01

    This paper presents a local intensity structure analysis based on an intensity targeted radial structure tensor (ITRST) and the blob-like structure enhancement filter based on it (ITRST filter) for the mediastinal lymph node detection algorithm from chest computed tomography (CT) volumes. Although the filter based on radial structure tensor analysis (RST filter) based on conventional RST analysis can be utilized to detect lymph nodes, some lymph nodes adjacent to regions with extremely high or low intensities cannot be detected. Therefore, we propose the ITRST filter, which integrates the prior knowledge on detection target intensity range into the RST filter. Our lymph node detection algorithm consists of two steps: (1) obtaining candidate regions using the ITRST filter and (2) removing false positives (FPs) using the support vector machine classifier. We evaluated lymph node detection performance of the ITRST filter on 47 contrast-enhanced chest CT volumes and compared it with the RST and Hessian filters. The detection rate of the ITRST filter was 84.2% with 9.1 FPs/volume for lymph nodes whose short axis was at least 10 mm, which outperformed the RST and Hessian filters.

  3. New conformity indices based on the calculation of distances between the target volume and the volume of reference isodose

    Science.gov (United States)

    Park, J M; Park, S-Y; Ye, S-J; Kim, J H; Carlson, J

    2014-01-01

    Objective: To present conformity indices (CIs) based on the distance differences between the target volume (TV) and the volume of reference isodose (VRI). Methods: The points on the three-dimensional surfaces of the TV and the VRI were generated. Then, the averaged distances between the points on the TV and the VRI were calculated (CIdistance). The performance of the presented CIs were evaluated by analysing six situations, which were a perfect match, an expansion and a reduction of the distance from the centroid to the VRI compared with the distance from the centroid to the TV by 10%, a lateral shift of the VRI by 3 cm, a rotation of the VRI by 45° and a spherical-shaped VRI having the same volume as the TV. The presented CIs were applied to the clinical prostate and head and neck (H&N) plans. Results: For the perfect match, CIdistance was 0 with 0 as the standard deviation (SD). When expanding and reducing, CIdistance was 10 and −10 with SDs 11. The average value of the CIdistance in the prostate and H&N plans was 0.13 ± 7.44 and 6.04 ± 23.27, respectively. Conclusion: The performance of the CIdistance was equal or better than those of the conventional CIs. Advances in knowledge: The evaluation of target conformity by the distances between the surface of the TV and the VRI could be more accurate than evaluation with volume information. PMID:25225915

  4. Automated planning target volume generation: an evaluation pitting a computer-based tool against human experts

    International Nuclear Information System (INIS)

    Ketting, Case H.; Austin-Seymour, Mary; Kalet, Ira; Jacky, Jon; Kromhout-Schiro, Sharon; Hummel, Sharon; Unger, Jonathan; Fagan, Lawrence M.; Griffin, Tom

    1997-01-01

    Purpose: Software tools are seeing increased use in three-dimensional treatment planning. However, the development of these tools frequently omits careful evaluation before placing them in clinical use. This study demonstrates the application of a rigorous evaluation methodology using blinded peer review to an automated software tool that produces ICRU-50 planning target volumes (PTVs). Methods and Materials: Seven physicians from three different institutions involved in three-dimensional treatment planning participated in the evaluation. Four physicians drew partial PTVs on nine test cases, consisting of four nasopharynx and five lung primaries. Using the same information provided to the human experts, the computer tool generated PTVs for comparison. The remaining three physicians, designated evaluators, individually reviewed the PTVs for acceptability. To exclude bias, the evaluators were blinded to the source (human or computer) of the PTVs they reviewed. Their scorings of the PTVs were statistically examined to determine if the computer tool performed as well as the human experts. Results: The computer tool was as successful as the human experts in generating PTVs. Failures were primarily attributable to insufficient margins around the clinical target volume and to encroachment upon critical structures. In a qualitative analysis, the human and computer experts displayed similar types and distributions of errors. Conclusions: Rigorous evaluation of computer-based radiotherapy tools requires comparison to current practice and can reveal areas for improvement before the tool enters clinical practice

  5. Calculation of Lung Cancer Volume of Target Based on Thorax Computed Tomography Images using Active Contour Segmentation Method for Treatment Planning System

    Science.gov (United States)

    Patra Yosandha, Fiet; Adi, Kusworo; Edi Widodo, Catur

    2017-06-01

    In this research, calculation process of the lung cancer volume of target based on computed tomography (CT) thorax images was done. Volume of the target calculation was done in purpose to treatment planning system in radiotherapy. The calculation of the target volume consists of gross tumor volume (GTV), clinical target volume (CTV), planning target volume (PTV) and organs at risk (OAR). The calculation of the target volume was done by adding the target area on each slices and then multiply the result with the slice thickness. Calculations of area using of digital image processing techniques with active contour segmentation method. This segmentation for contouring to obtain the target volume. The calculation of volume produced on each of the targets is 577.2 cm3 for GTV, 769.9 cm3 for CTV, 877.8 cm3 for PTV, 618.7 cm3 for OAR 1, 1,162 cm3 for OAR 2 right, and 1,597 cm3 for OAR 2 left. These values indicate that the image processing techniques developed can be implemented to calculate the lung cancer target volume based on CT thorax images. This research expected to help doctors and medical physicists in determining and contouring the target volume quickly and precisely.

  6. Dose-volume analysis of target volume and critical structures in computed tomography image-based multicatheter high-dose-rate interstitial brachytherapy for head and neck cancer

    Directory of Open Access Journals (Sweden)

    Hironori Akiyama

    2017-12-01

    Full Text Available Purpose : To evaluate dose-volume relationships of target volume and critical structures in computed tomography (CT image-based brachytherapy for head and neck cancer. Material and methods : Thirty-seven patients with mobile tongue, floor of mouth, and base of tongue cancer treated with brachytherapy (post-operative alone and as a boost after external beam radiotherapy [EBRT], or definitive alone or as a boost after EBRT were selected. Treatment plans were made using post-implant CT images. The fractionation schedule was 7-15 × 3-5 Gy for post-operative (with or without EBRT, 14-15 × 3 Gy for definitive alone, and 5-10 × 3 Gy for boost treatments. For the target volume, V 100 , D 90 , and dose non-uniformity ratio (DNR were calculated. For the mandible, spinal cord and salivary glands doses to specified volumes were reported. Results : The median values of V 100 and D 90 were 89.9% and 99.9%, respectively; the median values of DNR was 0.46. The median D 2cm 3 of the mandible and spinal cord were 48.3% and 5.8%, respectively. The ipsilateral median D 2cm 3 of parotid and submandibular glands were 6.4% and 12.5%, whereas on the contralateral side, the corresponding values were 5.3% and 7.0%, respectively. Conclusions : Using conformal treatment planning, it was desirable to keep the dose to the mandible, spinal cord, and salivary glands at an acceptable level. The quantitative plan evaluation may help us find correlations between dosimetric parameters and clinical outcome, which may lead to improve the quality of the treatment, but it requires longer follow-up and results from other studies.

  7. Evaluation of atlas based auto-segmentation for head and neck target volume delineation in adaptive/replan IMRT

    International Nuclear Information System (INIS)

    Speight, R; Lindsay, R; Harding, R; Sykes, J; Karakaya, E; Prestwich, R; Sen, M

    2014-01-01

    IMRT for head and neck patients requires clinicians to delineate clinical target volumes (CTV) on a planning-CT (>2hrs/patient). When patients require a replan-CT, CTVs must be re-delineated. This work assesses the performance of atlas-based autosegmentation (ABAS), which uses deformable image registration between planning and replan-CTs to auto-segment CTVs on the replan-CT, based on the planning contours. Fifteen patients with planning-CT and replan-CTs were selected. One clinician delineated CTVs on the planning-CTs and up to three clinicians delineated CTVs on the replan-CTs. Replan-CT volumes were auto-segmented using ABAS using the manual CTVs from the planning-CT as an atlas. ABAS CTVs were edited manually to make them clinically acceptable. Clinicians were timed to estimate savings using ABAS. CTVs were compared using dice similarity coefficient (DSC) and mean distance to agreement (MDA). Mean inter-observer variability (DSC>0.79 and MDA<2.1mm) was found to be greater than intra-observer variability (DSC>0.91 and MDA<1.5mm). Comparing ABAS to manual CTVs gave DSC=0.86 and MDA=2.07mm. Once edited, ABAS volumes agreed more closely with the manual CTVs (DSC=0.87 and MDA=1.87mm). The mean clinician time required to produce CTVs reduced from 169min to 57min when using ABAS. ABAS segments volumes with accuracy close to inter-observer variability however the volumes require some editing before clinical use. Using ABAS reduces contouring time by a factor of three.

  8. A clip-based protocol for breast boost radiotherapy provides clear target visualisation and demonstrates significant volume reduction over time

    International Nuclear Information System (INIS)

    Lewis, Lorraine; Cox, Jennifer; Morgia, Marita; Atyeo, John; Lamoury, Gillian

    2015-01-01

    The clinical target volume (CTV) for early stage breast cancer is difficult to clearly identify on planning computed tomography (CT) scans. Surgical clips inserted around the tumour bed should help to identify the CTV, particularly if the seroma has been reabsorbed, and enable tracking of CTV changes over time. A surgical clip-based CTV delineation protocol was introduced. CTV visibility and its post-operative shrinkage pattern were assessed. The subjects were 27 early stage breast cancer patients receiving post-operative radiotherapy alone and 15 receiving post-operative chemotherapy followed by radiotherapy. The radiotherapy alone (RT/alone) group received a CT scan at median 25 days post-operatively (CT1rt) and another at 40 Gy, median 68 days (CT2rt). The chemotherapy/RT group (chemo/RT) received a CT scan at median 18 days post-operatively (CT1ch), a planning CT scan at median 126 days (CT2ch), and another at 40 Gy (CT3ch). There was no significant difference (P = 0.08) between the initial mean CTV for each cohort. The RT/alone cohort showed significant CTV volume reduction of 38.4% (P = 0.01) at 40 Gy. The Chemo/RT cohort had significantly reduced volumes between CT1ch: median 54 cm 3 (4–118) and CT2ch: median 16 cm 3 , (2–99), (P = 0.01), but no significant volume reduction thereafter. Surgical clips enable localisation of the post-surgical seroma for radiotherapy targeting. Most seroma shrinkage occurs early, enabling CT treatment planning to take place at 7 weeks, which is within the 9 weeks recommended to limit disease recurrence

  9. A clip-based protocol for breast boost radiotherapy provides clear target visualisation and demonstrates significant volume reduction over time

    Energy Technology Data Exchange (ETDEWEB)

    Lewis, Lorraine [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Cox, Jennifer [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Faculty of Health Sciences, University of Sydney, Sydney, New South Wales (Australia); Morgia, Marita [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia); Atyeo, John [Faculty of Health Sciences, University of Sydney, Sydney, New South Wales (Australia); Lamoury, Gillian [Department of Radiation Oncology, Northern Sydney Cancer Centre, Royal North Shore Hospital, Sydney, New South Wales (Australia)

    2015-09-15

    The clinical target volume (CTV) for early stage breast cancer is difficult to clearly identify on planning computed tomography (CT) scans. Surgical clips inserted around the tumour bed should help to identify the CTV, particularly if the seroma has been reabsorbed, and enable tracking of CTV changes over time. A surgical clip-based CTV delineation protocol was introduced. CTV visibility and its post-operative shrinkage pattern were assessed. The subjects were 27 early stage breast cancer patients receiving post-operative radiotherapy alone and 15 receiving post-operative chemotherapy followed by radiotherapy. The radiotherapy alone (RT/alone) group received a CT scan at median 25 days post-operatively (CT1rt) and another at 40 Gy, median 68 days (CT2rt). The chemotherapy/RT group (chemo/RT) received a CT scan at median 18 days post-operatively (CT1ch), a planning CT scan at median 126 days (CT2ch), and another at 40 Gy (CT3ch). There was no significant difference (P = 0.08) between the initial mean CTV for each cohort. The RT/alone cohort showed significant CTV volume reduction of 38.4% (P = 0.01) at 40 Gy. The Chemo/RT cohort had significantly reduced volumes between CT1ch: median 54 cm{sup 3} (4–118) and CT2ch: median 16 cm{sup 3}, (2–99), (P = 0.01), but no significant volume reduction thereafter. Surgical clips enable localisation of the post-surgical seroma for radiotherapy targeting. Most seroma shrinkage occurs early, enabling CT treatment planning to take place at 7 weeks, which is within the 9 weeks recommended to limit disease recurrence.

  10. Integrating respiratory-gated PET-based target volume delineation in liver SBRT planning, a pilot study

    International Nuclear Information System (INIS)

    Riou, Olivier; Thariat, Juliette; Serrano, Benjamin; Azria, David; Paulmier, Benoit; Villeneuve, Remy; Fenoglietto, Pascal; Artenie, Antonella; Ortholan, Cécile; Faraggi, Marc

    2014-01-01

    To assess the feasibility and benefit of integrating four-dimensional (4D) Positron Emission Tomography (PET) – computed tomography (CT) for liver stereotactic body radiation therapy (SBRT) planning. 8 patients with 14 metastases were accrued in the study. They all underwent a non-gated PET and a 4D PET centered on the liver. The same CT scan was used for attenuation correction, registration, and considered the planning CT for SBRT planning. Six PET phases were reconstructed for each 4D PET. By applying an individualized threshold to the 4D PET, a Biological Internal Target Volume (BITV) was generated for each lesion. A gated Planning Target Volume (PTVg) was created by adding 3 mm to account for set-up margins. This volume was compared to a manual Planning Target Volume (PTV) delineated with the help of a semi-automatic Biological Target Volume (BTV) obtained from the non-gated exam. A 5 mm radial and a 10 mm craniocaudal margins were applied to account for tumor motion and set-up margins to create the PTV. One undiagnosed liver metastasis was discovered thanks to the 4D PET. The semi-automatic BTV were significantly smaller than the BITV (p = 0.0031). However, after applying adapted margins, 4D PET allowed a statistically significant decrease in the PTVg as compared to the PTV (p = 0.0052). In comparison to non-gated PET, 4D PET may better define the respiratory movements of liver targets and improve SBRT planning for liver metastases. Furthermore, non respiratory-gated PET exams can both misdiagnose liver metastases and underestimate the real internal target volumes

  11. Influence of experience and qualification on PET-based target volume delineation. When there is no expert - ask your colleague

    International Nuclear Information System (INIS)

    Doll, C.; Grosu, A.L.; Nestle, U.; Duncker-Rohr, V.; Ruecker, G.; Mix, M.; MacManus, M.; Ruysscher, D. de; Vogel, W.; Eriksen, J.G.; Oyen, W.; Weber, W.

    2014-01-01

    The integration of positron emission tomography (PET) information for target volume delineation in radiation treatment planning is routine in many centers. In contrast to automatic contouring, research on visual-manual delineation is scarce. The present study investigates the dependency of manual delineation on experience and qualification. A total of 44 international interdisciplinary observers each defined a [ 18 F]fluorodeoxyglucose (FDG)-PET based gross tumor volume (GTV) using the same PET/CT scan from a patient with lung cancer. The observers were ''experts'' (E; n = 3), ''experienced interdisciplinary pairs'' (EP; 9 teams of radiation oncologist (RO) + nuclear medicine physician (NP)), ''single field specialists'' (SFS; n = 13), and ''students'' (S; n = 10). Five automatic delineation methods (AM) were also included. Volume sizes and concordance indices within the groups (pCI) and relative to the experts (eCI) were calculated. E (pCI = 0.67) and EP (pCI = 0.53) showed a significantly higher agreement within the groups as compared to SFS (pCI = 0.43, p = 0.03, and p = 0.006). In relation to the experts, EP (eCI = 0.55) showed better concordance compared to SFS (eCI = 0.49) or S (eCI = 0.47). The intermethod variability of the AM (pCI = 0.44) was similar to that of SFS and S, showing poorer agreement with the experts (eCI = 0.35). The results suggest that interdisciplinary cooperation could be beneficial for consistent contouring. Joint delineation by a radiation oncologist and a nuclear medicine physician showed remarkable agreement and better concordance with the experts compared to other specialists. The relevant intermethod variability of the automatic algorithms underlines the need for further standardization and optimization in this field. (orig.) [de

  12. A consensus-based guideline defining clinical target volume for primary disease in external beam radiotherapy for intact uterine cervical cancer

    International Nuclear Information System (INIS)

    Toita, Takafumi; Ohno, Tatsuya; Kaneyasu, Yuko

    2011-01-01

    The objective of this study was to develop a consensus-based guideline to define clinical target volume for primary disease (clinical target volume primary) in external beam radiotherapy for intact uterine cervical cancer. The working subgroup of the Japan Clinical Oncology Group (JCOG) Radiation Therapy Study Group began developing a guideline for primary clinical target volume in November 2009. The group consisted of 10 radiation oncologists and 2 gynecologic oncologists. The process started with comparing the contouring on computed tomographic images of actual cervical cancer cases among the members. This was followed by a comprehensive literature review that included primary research articles and textbooks as well as information on surgical procedures. Extensive discussion occurred in face-to-face meetings (three occasions) and frequent e-mail communications until a consensus was reached. The working subgroup reached a consensus on the definition for the clinical target volume primary. The clinical target volume primary consists of the gross tumor volume, uterine cervix, uterine corpus, parametrium, vagina and ovaries. Definitions for these component structures were determined. Anatomical boundaries in all directions were defined for the parametrium. Examples delineating these boundaries were prepared for the posterior border of the parametrium for various clinical situations (id est (i.e.) central tumor bulk, degree of parametrial involvement). A consensus-based guideline defining the clinical target volume primary was developed for external beam radiotherapy for intact uterine cervical cancer. This guideline will serve as a template for radiotherapy protocols in future clinical trials. It may also be used in actual clinical practice in the setting of highly precise external beam radiotherapy, including intensity-modulated radiotherapy. (author)

  13. Small volume target for F-18 production

    Science.gov (United States)

    Pellicioli, M.; Schuler, J.; Marchand, P.; Brasse, D.

    2017-05-01

    In order to reduce the volume of O-18 enriched water used for each F-18 production for research a small volume target of 1 ml has been designed at IPHC. The designed is derived from ACSI 3.8ml F-18 target and uses both water and Helium cooling. After one year of use production yield is reported.

  14. A Comparison of Amplitude-Based and Phase-Based Positron Emission Tomography Gating Algorithms for Segmentation of Internal Target Volumes of Tumors Subject to Respiratory Motion

    Energy Technology Data Exchange (ETDEWEB)

    Jani, Shyam S., E-mail: sjani@mednet.ucla.edu [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); Robinson, Clifford G. [Department of Radiation Oncology, Siteman Cancer Center, Washington University in St Louis, St Louis, Missouri (United States); Dahlbom, Magnus [Department of Molecular and Medical Pharmacology, David Geffen School of Medicine, University of California, Los Angeles, California (United States); White, Benjamin M.; Thomas, David H.; Gaudio, Sergio; Low, Daniel A.; Lamb, James M. [Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, California (United States)

    2013-11-01

    Purpose: To quantitatively compare the accuracy of tumor volume segmentation in amplitude-based and phase-based respiratory gating algorithms in respiratory-correlated positron emission tomography (PET). Methods and Materials: List-mode fluorodeoxyglucose-PET data was acquired for 10 patients with a total of 12 fluorodeoxyglucose-avid tumors and 9 lymph nodes. Additionally, a phantom experiment was performed in which 4 plastic butyrate spheres with inner diameters ranging from 1 to 4 cm were imaged as they underwent 1-dimensional motion based on 2 measured patient breathing trajectories. PET list-mode data were gated into 8 bins using 2 amplitude-based (equal amplitude bins [A1] and equal counts per bin [A2]) and 2 temporal phase-based gating algorithms. Gated images were segmented using a commercially available gradient-based technique and a fixed 40% threshold of maximum uptake. Internal target volumes (ITVs) were generated by taking the union of all 8 contours per gated image. Segmented phantom ITVs were compared with their respective ground-truth ITVs, defined as the volume subtended by the tumor model positions covering 99% of breathing amplitude. Superior-inferior distances between sphere centroids in the end-inhale and end-exhale phases were also calculated. Results: Tumor ITVs from amplitude-based methods were significantly larger than those from temporal-based techniques (P=.002). For lymph nodes, A2 resulted in ITVs that were significantly larger than either of the temporal-based techniques (P<.0323). A1 produced the largest and most accurate ITVs for spheres with diameters of ≥2 cm (P=.002). No significant difference was shown between algorithms in the 1-cm sphere data set. For phantom spheres, amplitude-based methods recovered an average of 9.5% more motion displacement than temporal-based methods under regular breathing conditions and an average of 45.7% more in the presence of baseline drift (P<.001). Conclusions: Target volumes in images generated

  15. A Comparison of Amplitude-Based and Phase-Based Positron Emission Tomography Gating Algorithms for Segmentation of Internal Target Volumes of Tumors Subject to Respiratory Motion

    International Nuclear Information System (INIS)

    Jani, Shyam S.; Robinson, Clifford G.; Dahlbom, Magnus; White, Benjamin M.; Thomas, David H.; Gaudio, Sergio; Low, Daniel A.; Lamb, James M.

    2013-01-01

    Purpose: To quantitatively compare the accuracy of tumor volume segmentation in amplitude-based and phase-based respiratory gating algorithms in respiratory-correlated positron emission tomography (PET). Methods and Materials: List-mode fluorodeoxyglucose-PET data was acquired for 10 patients with a total of 12 fluorodeoxyglucose-avid tumors and 9 lymph nodes. Additionally, a phantom experiment was performed in which 4 plastic butyrate spheres with inner diameters ranging from 1 to 4 cm were imaged as they underwent 1-dimensional motion based on 2 measured patient breathing trajectories. PET list-mode data were gated into 8 bins using 2 amplitude-based (equal amplitude bins [A1] and equal counts per bin [A2]) and 2 temporal phase-based gating algorithms. Gated images were segmented using a commercially available gradient-based technique and a fixed 40% threshold of maximum uptake. Internal target volumes (ITVs) were generated by taking the union of all 8 contours per gated image. Segmented phantom ITVs were compared with their respective ground-truth ITVs, defined as the volume subtended by the tumor model positions covering 99% of breathing amplitude. Superior-inferior distances between sphere centroids in the end-inhale and end-exhale phases were also calculated. Results: Tumor ITVs from amplitude-based methods were significantly larger than those from temporal-based techniques (P=.002). For lymph nodes, A2 resulted in ITVs that were significantly larger than either of the temporal-based techniques (P<.0323). A1 produced the largest and most accurate ITVs for spheres with diameters of ≥2 cm (P=.002). No significant difference was shown between algorithms in the 1-cm sphere data set. For phantom spheres, amplitude-based methods recovered an average of 9.5% more motion displacement than temporal-based methods under regular breathing conditions and an average of 45.7% more in the presence of baseline drift (P<.001). Conclusions: Target volumes in images generated

  16. Influence of experience and qualification on PET-based target volume delineation. When there is no expert - ask your colleague

    Energy Technology Data Exchange (ETDEWEB)

    Doll, C.; Grosu, A.L.; Nestle, U. [University Medical Center Freiburg, Radiation Oncology Department, Freiburg/Breisgau (Germany); Duncker-Rohr, V. [University Medical Center Freiburg, Radiation Oncology Department, Freiburg/Breisgau (Germany); Ortenau Clinical Center Offenburg, Radiation Oncology Department, Offenburg (Germany); Ruecker, G. [University of Freiburg, Institute of Medical Biometry und Medical Informatics, Freiburg (Germany); Mix, M. [University Medical Center Freiburg, Nuclear Medicine Department, Freiburg (Germany); MacManus, M. [University of Melbourne, The Sir Peter MacCallum Department of Oncology, Melbourne (Australia); Ruysscher, D. de [University Hospital Leuven/KU Leuven, Department of Radiation Oncology, Leuven (Belgium); Vogel, W. [Antoni van Leeuwenhoek Hospital, Department of Nuclear Medicine, The Netherlands Cancer Institute, Amsterdam (Netherlands); Eriksen, J.G. [Odense University Hospital, Department of Oncology, Odense (Denmark); Oyen, W. [Radboud University Nijmegen Medical Center, Department of Nuclear Medicine, Nijmegen (Netherlands); Weber, W. [University Medical Center Freiburg, Nuclear Medicine Department, Freiburg (Germany); Memorial Sloan-Kettering Cancer Center, Department of Radiology/Molecular Imaging and Therapy Service, New York (United States)

    2014-06-15

    The integration of positron emission tomography (PET) information for target volume delineation in radiation treatment planning is routine in many centers. In contrast to automatic contouring, research on visual-manual delineation is scarce. The present study investigates the dependency of manual delineation on experience and qualification. A total of 44 international interdisciplinary observers each defined a [{sup 18}F]fluorodeoxyglucose (FDG)-PET based gross tumor volume (GTV) using the same PET/CT scan from a patient with lung cancer. The observers were ''experts'' (E; n = 3), ''experienced interdisciplinary pairs'' (EP; 9 teams of radiation oncologist (RO) + nuclear medicine physician (NP)), ''single field specialists'' (SFS; n = 13), and ''students'' (S; n = 10). Five automatic delineation methods (AM) were also included. Volume sizes and concordance indices within the groups (pCI) and relative to the experts (eCI) were calculated. E (pCI = 0.67) and EP (pCI = 0.53) showed a significantly higher agreement within the groups as compared to SFS (pCI = 0.43, p = 0.03, and p = 0.006). In relation to the experts, EP (eCI = 0.55) showed better concordance compared to SFS (eCI = 0.49) or S (eCI = 0.47). The intermethod variability of the AM (pCI = 0.44) was similar to that of SFS and S, showing poorer agreement with the experts (eCI = 0.35). The results suggest that interdisciplinary cooperation could be beneficial for consistent contouring. Joint delineation by a radiation oncologist and a nuclear medicine physician showed remarkable agreement and better concordance with the experts compared to other specialists. The relevant intermethod variability of the automatic algorithms underlines the need for further standardization and optimization in this field. (orig.) [German] Die Daten aus der Positronenemissionstomographie (PET) werden in vielen Kliniken routinemaessig zur

  17. A consensus-based guideline defining the clinical target volume for pelvic lymph nodes in external beam radiotherapy for uterine cervical cancer

    International Nuclear Information System (INIS)

    Toita, Takafumi; Ohno, Tatsuya; Kaneyasu, Yuko

    2010-01-01

    The objective of this study was to develop a consensus-based guideline as well as an atlas defining pelvic nodal clinical target volumes in external beam radiotherapy for uterine cervical cancer. A working subgroup to establish the consensus-based guideline on clinical target volumes for uterine cervical cancer was formulated by the Radiation Therapy Study Group of the Japan Clinical Oncology Group in July 2008. The working subgroup consisted of seven radiation oncologists. The process resulting in the consensus included a comparison of contouring on CT images among the members, reviewing of published textbooks and the relevant literature and a distribution analysis of metastatic nodes on computed tomography/magnetic resonance imaging of actual patients. The working subgroup defined the pelvic nodal clinical target volumes for cervical cancer and developed an associated atlas. As a basic criterion, the lymph node clinical target volume was defined as the area encompassed by a 7 mm margin around the applicable pelvic vessels. Modifications were made in each nodal area to cover adjacent adipose tissues at risk of microscopic nodal metastases. Although the bones and muscles were excluded, the bowel was not routinely excluded in the definition. Each of the following pelvic node regions was defined: common iliac, external iliac, internal iliac, obturator and presacral. Anatomical structures bordering each lymph node region were defined for six directions; anterior, posterior, lateral, medial, cranial and caudal. Drafts of the definition and the atlas were reviewed by members of the JCOG Gynecologic Cancer Study Group (GCSG). We developed a consensus-based guideline defining the pelvic node clinical target volumes that included an atlas. The guideline will be continuously updated to reflect the ongoing changes in the field. (author)

  18. Magnetic Resonance Imaging-Based Target Volume Delineation in Radiation Therapy Treatment Planning for Brain Tumors Using Localized Region-Based Active Contour

    International Nuclear Information System (INIS)

    Aslian, Hossein; Sadeghi, Mahdi; Mahdavi, Seied Rabie; Babapour Mofrad, Farshid; Astarakee, Mahdi; Khaledi, Navid; Fadavi, Pedram

    2013-01-01

    Purpose: To evaluate the clinical application of a robust semiautomatic image segmentation method to determine the brain target volumes in radiation therapy treatment planning. Methods and Materials: A local robust region-based algorithm was used on MRI brain images to study the clinical target volume (CTV) of several patients. First, 3 oncologists delineated CTVs of 10 patients manually, and the process time for each patient was calculated. The averages of the oncologists’ contours were evaluated and considered as reference contours. Then, to determine the CTV through the semiautomatic method, a fourth oncologist who was blind to all manual contours selected 4-8 points around the edema and defined the initial contour. The time to obtain the final contour was calculated again for each patient. Manual and semiautomatic segmentation were compared using 3 different metric criteria: Dice coefficient, Hausdorff distance, and mean absolute distance. A comparison also was performed between volumes obtained from semiautomatic and manual methods. Results: Manual delineation processing time of tumors for each patient was dependent on its size and complexity and had a mean (±SD) of 12.33 ± 2.47 minutes, whereas it was 3.254 ± 1.7507 minutes for the semiautomatic method. Means of Dice coefficient, Hausdorff distance, and mean absolute distance between manual contours were 0.84 ± 0.02, 2.05 ± 0.66 cm, and 0.78 ± 0.15 cm, and they were 0.82 ± 0.03, 1.91 ± 0.65 cm, and 0.7 ± 0.22 cm between manual and semiautomatic contours, respectively. Moreover, the mean volume ratio (=semiautomatic/manual) calculated for all samples was 0.87. Conclusions: Given the deformability of this method, the results showed reasonable accuracy and similarity to the results of manual contouring by the oncologists. This study shows that the localized region-based algorithms can have great ability in determining the CTV and can be appropriate alternatives for manual approaches in brain cancer

  19. Efficient approach for determining four-dimensional computed tomography-based internal target volume in stereotactic radiotherapy of lung cancer

    International Nuclear Information System (INIS)

    Yeo, Seung Gu; Kim, Eun Seog

    2013-01-01

    This study aimed to investigate efficient approaches for determining internal target volume (ITV) from four-dimensional computed tomography (4D CT) images used in stereotactic body radiotherapy (SBRT) for patients with early-stage non-small cell lung cancer (NSCLC). 4D CT images were analyzed for 15 patients who received SBRT for stage I NSCLC. Three different ITVs were determined as follows: combining clinical target volume (CTV) from all 10 respiratory phases (ITV 10Phases ); combining CTV from four respiratory phases, including two extreme phases (0% and 50%) plus two intermediate phases (20% and 70%) (ITV 4Phases ); and combining CTV from two extreme phases (ITV 2Phases ). The matching index (MI) of ITV 4Phases and ITV 2Phases was defined as the ratio of ITV 4Phases and ITV 2Phases , respectively, to the ITV 10Phases . The tumor motion index (TMI) was defined as the ratio of ITV 10Phases to CTV mean , which was the mean of 10 CTVs delineated on 10 respiratory phases. The ITVs were significantly different in the order of ITV 10Phases , ITV 4Phases , and ITV 2Phases (all p 4Phases was significantly higher than that of ITV 2Phases (p 4Phases was inversely related to TMI (r = -0.569, p = 0.034). In a subgroup with low TMI (n = 7), ITV 4Phases was not statistically different from ITV 10Phases (p = 0.192) and its MI was significantly higher than that of ITV 2Phases (p = 0.016). The ITV 4Phases may be an efficient approach alternative to optimal ITV 10Phases in SBRT for early-stage NSCLC with less tumor motion.

  20. A comparative study on the volume and localization of the internal gross target volume defined using the seroma and surgical clips based on 4DCT scan for external-beam partial breast irradiation after breast conserving surgery

    International Nuclear Information System (INIS)

    Ding, Yun; Li, Jianbin; Wang, Wei; Wang, Suzhen; Wang, Jinzhi; Ma, Zhifang; Shao, Qian; Xu, Min

    2014-01-01

    To explore the volume and localization of the internal gross target volume defined using the seroma and/or surgical clips based on the four-dimensional computed tomography (4DCT) during free-breathing. Fifteen breast cancer patients after breast-conserving surgery (BCS) were recruited for EB-PBI. On the ten sets CT images, the gross target volume formed by the clips, the seroma, both the clips and seroma delineated by one radiation oncologist and defined as GTVc, GTVs and GTVc + s, respectively. The ten GTVc, GTVs and GTVc + s on the ten sets CT images produced the IGTVc, IGTVs, IGTVc + s, respectively. The IGTV volume and the distance between the center of IGTVc, IGTVs, IGTVc + s were all recorded. Conformity index (CI), degree of inclusion (DI) were calculated for IGTV/IGTV, respectively. The volume of IGTVc + s were significantly larger than the IGTVc and IGTVs (p < 0.05). There was significant difference between the DIs of IGTVc vs IGTVc + s, the DIs of IGTVs vs IGTVc + s. There was significant difference among the CIs of IGTV/IGTV. The DIs and CIs of IGTV/IGTV were negatively correlated with their centroid distance (r < 0, p < 0.05). There were volume difference and spatial mismatch between the IGTVs delineated based on the surgical clips and seroma. The IGTV defined as the seroma and surgical clips provided the best overall representation of the ‘true’ moving GTV

  1. Determination and delineation of nodal target volumes for head-and-neck cancer based on patterns of failure in patients receiving definitive and postoperative IMRT

    International Nuclear Information System (INIS)

    Chao, K.S. Clifford; Wippold, Franz J.; Ozyigit, Gokhan; Tran, Binh N.; Dempsey, James F.

    2002-01-01

    Purpose: We present the guidelines for target volume determination and delineation of head-and-neck lymph nodes based on the analysis of the patterns of nodal failure in patients treated with intensity-modulated radiotherapy (IMRT). Methods and Materials: Data pertaining to the natural course of nodal metastasis for each head-and-neck cancer subsite were reviewed. A system was established to provide guidance for nodal target volume determination and delineation. Following these guidelines, 126 patients (52 definitive, 74 postoperative) were treated between February 1997 and December 2000 with IMRT for head-and-neck cancer. The median follow-up was 26 months (range 12-55), and the patterns of nodal failure were analyzed. Results: These guidelines define the nodal target volume based on the location of the primary tumor and the probability of microscopic metastasis to the ipsilateral and contralateral (Level I-V) nodal regions. Following these guidelines, persistent or recurrent nodal disease was found in 6 (12%) of 52 patients receiving definitive IMRT, and 7 (9%) of 74 patients receiving postoperative IMRT had failure in the nodal region. Conclusion: On the basis of our clinical experience in implementing inverse-planning IMRT for head-and-neck cancer, we present guidelines using a simplified, but clinically relevant, method for nodal target volume determination and delineation. The intention was to provide a foundation that enables different institutions to exchange clinical experiences in head-and-neck IMRT. These guidelines will be subject to future refinement when the clinical experience in head-and-neck IMRT advances

  2. Comparison of Computed Tomography– and Magnetic Resonance Imaging–based Clinical Target Volume Contours at Brachytherapy for Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Swanick, Cameron W. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Castle, Katherine O. [Southeast Louisiana Radiation Oncology Group, Baton Rouge, Louisiana (United States); Vedam, Sastry [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Munsell, Mark F. [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Turner, Lehendrick M. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Rauch, Gaiane M. [Department of Diagnostic Radiology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jhingran, Anuja; Eifel, Patricia J. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Klopp, Ann H., E-mail: aklopp@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-11-15

    Purpose: We prospectively compared computed tomography (CT)– and magnetic resonance imaging (MRI)–based high-risk clinical target volume (HR-CTV) contours at the time of brachytherapy for cervical cancer in an effort to identify patients who might benefit most from MRI-based planning. Methods and Materials: Thirty-seven patients who had undergone a pretreatment diagnostic MRI scan were included in the analysis. We delineated the HR-CTV on the brachytherapy CT and brachytherapy MRI scans independently for each patient. We then calculated the absolute volumes for each HR-CTV and the Dice coefficient of similarity (DC, a measure of spatial agreement) for the HR-CTV contours. We identified the clinical and tumor factors associated with (1) a discrepancy in volume between the CT HR-CTV and MRI HR-CTV contours; and (2) DC. The mean values were compared using 1-way analysis of variance or paired or unpaired t tests, as appropriate. Simple and multivariable linear regression analyses were used to model the effects of covariates on the outcomes. Results: Patients with International Federation of Gynecology and Obstetrics stage IB to IVA cervical cancer were treated with intracavitary brachytherapy using tandem and ovoid (n=33) or tandem and cylinder (n=4) applicators. The mean CT HR-CTV volume (44.1 cm{sup 3}) was larger than the mean MRI HR-CTV volume (35.1 cm{sup 3}; P<.0001, paired t test). On multivariable analysis, a higher body mass index (BMI) and tumor size ≥5 cm with parametrial invasion on the MRI scan at diagnosis were associated with an increased discrepancy in volume between the HR-CTV contours (P<.02 for both). In addition, the spatial agreement (as measured by DC) between the HR-CTV contours decreased with an increasing BMI (P=.013). Conclusions: We recommend MRI-based brachytherapy planning for patients with tumors >5 cm and parametrial invasion on MRI at diagnosis and for those with a high BMI.

  3. Drug and enzyme targeting. Methods in enzymology. Volume 112

    International Nuclear Information System (INIS)

    Widder, K.J.; Green, R.

    1985-01-01

    In evaluating methods of drug and enzyme targeting, studies are included which discuss microencapsulation techniques and the preparation and purification of various drug conjugates and radiopharmaceuticals, which can be used as a carrier that either releases the drug more slowly or targets the drug more selectively on the desired tissue. Separate abstracts have been prepared for five chapters of this volume for inclusion in the Energy Data Base

  4. Impact of PET and MRI threshold-based tumor volume segmentation on patient-specific targeted radionuclide therapy dosimetry using CLR1404

    Science.gov (United States)

    Besemer, Abigail E.; Titz, Benjamin; Grudzinski, Joseph J.; Weichert, Jamey P.; Kuo, John S.; Robins, H. Ian; Hall, Lance T.; Bednarz, Bryan P.

    2017-08-01

    Variations in tumor volume segmentation methods in targeted radionuclide therapy (TRT) may lead to dosimetric uncertainties. This work investigates the impact of PET and MRI threshold-based tumor segmentation on TRT dosimetry in patients with primary and metastatic brain tumors. In this study, PET/CT images of five brain cancer patients were acquired at 6, 24, and 48 h post-injection of 124I-CLR1404. The tumor volume was segmented using two standardized uptake value (SUV) threshold levels, two tumor-to-background ratio (TBR) threshold levels, and a T1 Gadolinium-enhanced MRI threshold. The dice similarity coefficient (DSC), jaccard similarity coefficient (JSC), and overlap volume (OV) metrics were calculated to compare differences in the MRI and PET contours. The therapeutic 131I-CLR1404 voxel-level dose distribution was calculated from the 124I-CLR1404 activity distribution using RAPID, a Geant4 Monte Carlo internal dosimetry platform. The TBR, SUV, and MRI tumor volumes ranged from 2.3-63.9 cc, 0.1-34.7 cc, and 0.4-11.8 cc, respectively. The average  ±  standard deviation (range) was 0.19  ±  0.13 (0.01-0.51), 0.30  ±  0.17 (0.03-0.67), and 0.75  ±  0.29 (0.05-1.00) for the JSC, DSC, and OV, respectively. The DSC and JSC values were small and the OV values were large for both the MRI-SUV and MRI-TBR combinations because the regions of PET uptake were generally larger than the MRI enhancement. Notable differences in the tumor dose volume histograms were observed for each patient. The mean (standard deviation) 131I-CLR1404 tumor doses ranged from 0.28-1.75 Gy GBq-1 (0.07-0.37 Gy GBq-1). The ratio of maximum-to-minimum mean doses for each patient ranged from 1.4-2.0. The tumor volume and the interpretation of the tumor dose is highly sensitive to the imaging modality, PET enhancement metric, and threshold level used for tumor volume segmentation. The large variations in tumor doses clearly demonstrate the need for standard

  5. Irradiation of target volumes with concave outlines

    Energy Technology Data Exchange (ETDEWEB)

    De Neve, W.; Fortan, L.; Derycke, S.; Van Duyse, B.; DE Wagter, C. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde

    1995-12-01

    A heuristic planning procedure allowing to obtain a 3-dimensional conformal dose distribution for target volumes with concavities has been investigated. The procedure divides the planning problem into a number of sub-problems each solvable by known methods. By patching together the solutions to the sub-problems, a solution with a predictable dosimetric outcome can be obtained. The procedure can be applied to most 3-dimensional systems. The procedure is described and its applications to the irradiation of neoplasms are discussed. (A.S.).

  6. Target volume definition in radiation oncology

    CERN Document Server

    Grosu, Anca-Ligia

    2015-01-01

    The main objective of this book is to provide radiation oncologists with a clear, up-to-date guide to tumor delineation and contouring of organs at risk. With this in mind, a detailed overview of recent advances in imaging for radiation treatment planning is presented. Novel concepts for target volume delineation are explained, taking into account the innovations in imaging technology. Special attention is paid to the role of the newer imaging modalities, such as positron emission tomography and diffusion and perfusion magnetic resonance imaging. All of the most important tumor entities treate

  7. Definition of the key target volume in radiosurgical management of arteriovenous malformations: a new dynamic concept based on angiographic circulation time.

    Science.gov (United States)

    Valle, Ramiro Del; Zenteno, Marco; Jaramillo, José; Lee, Angel; De Anda, Salvador

    2008-12-01

    The cumulative experience worldwide indicates complete radiosurgical obliteration rates of brain arteriovenous malformations (AVMs) ranging from 35 to 90%. The purpose of this study was to propose a strategy to increase the obliteration rate for AVMs through the dynamic definition of the key target volume (KTV). A prospective series of patients harboring an AVM was assessed using digital subtraction angiography in which a digital counter was used to measure the several stages of the frame-by-frame circulation time. All the patients were analyzed using dynamic measurement planning to define the KTV, corresponding to the volume of the shunt with the least vascular resistance and the earliest venous drainage. All patients underwent catheter-based angiography, a subgroup was additionally assessed by means of a superselective catheterization, and among these a further subgroup received embolization. The shunts were also categorized according to their angioarchitectural type: fistulous, plexiform, or mixed. The authors applied the radiosurgery-based grading system (RBGS) as well to find a correlation with the obliteration rate. This series includes 44 patients treated by radiosurgery; global angiography was performed for all patients, including dynamic measurement planning. Eighty-four percent of them underwent superselective catheterization, and 50% of the total population underwent embolization. In the embolized arm of the study, the pretreatment volume was up to 120 ml. In patients with a single treatment, the mean volume was 8.5 ml, and the median volume was 6.95 +/- 4.56 ml (mean +/- standard deviation), with a KTV of up to 15 ml. For prospectively staged radiosurgery, the mean KTV was 28 ml. The marginal radiation dose was 18-22 Gy, with a mean of dose 20 Gy. The mean RBGS score was 1.70. The overall obliteration rate was 91%, including the repeated radiosurgery group (4 patients), in which 100% showed complete obliteration. The overall permanent deficit was 2 of

  8. Comparison and Consensus Guidelines for Delineation of Clinical Target Volume for CT- and MR-Based Brachytherapy in Locally Advanced Cervical Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Akila N., E-mail: aviswanathan@lroc.harvard.edu [Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Erickson, Beth [Medical College of Wisconsin, Milwaukee, Wisconsin (United States); Gaffney, David K. [University of Utah Huntsman Cancer Hospital, Salt Lake City, Utah (United States); Beriwal, Sushil [University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania (United States); Bhatia, Sudershan K. [University of Iowa, Iowa City, Iowa (United States); Lee Burnett, Omer [University of Alabama, Birmingham, Alabama (United States); D' Souza, David P.; Patil, Nikhilesh [London Health Sciences Centre and Western University, London, Ontario (Canada); Haddock, Michael G. [Mayo Medical Center, Rochester, Minnesota (United States); Jhingran, Anuja [University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Jones, Ellen L. [University of North Carolina, Chapel Hill, North Carolina (United States); Kunos, Charles A. [Case Western Reserve University, Cleveland, Ohio (United States); Lee, Larissa J. [Brigham and Women' s Hospital/Dana-Farber Cancer Institute, Boston, Massachusetts (United States); Lin, Lilie L. [University of Pennsylvania, Philadelphia, Pennsylvania (United States); Mayr, Nina A. [University of Washington, Seattle, Washington (United States); Petersen, Ivy [Mayo Medical Center, Rochester, Minnesota (United States); Petric, Primoz [Division of Radiotherapy, Institute of Oncology Ljubljana, Ljubljana (Slovenia); Department of Radiation Oncology, National Center for Cancer Care and Research, Doha (Qatar); Portelance, Lorraine [University of Miami Miller School of Medicine, Miami, Florida (United States); Small, William [Loyola University Strich School of Medicine, Chicago, Illinois (United States); Strauss, Jonathan B. [The Robert H. Lurie Comprehensive Cancer Center of Northwestern University, Chicago, Illinois (United States); and others

    2014-10-01

    Objective: To create and compare consensus clinical target volume (CTV) contours for computed tomography (CT) and 3-Tesla (3-T) magnetic resonance (MR) image-based cervical-cancer brachytherapy. Methods and Materials: Twenty-three experts in gynecologic radiation oncology contoured the same 3 cervical cancer brachytherapy cases: 1 stage IIB near-complete response (CR) case with a tandem and ovoid, 1 stage IIB partial response (PR) case with tandem and ovoid with needles, and 1 stage IB2 CR case with a tandem and ring applicator. The CT contours were completed before the MRI contours. These were analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with κ statistics as a measure of agreement between participants. The conformity index was calculated for each of the 6 data sets. Dice coefficients were generated to compare the CT and MR contours of the same case. Results: For all 3 cases, the mean tumor volume was smaller on MR than on CT (P<.001). The κ and conformity index estimates were slightly higher for CT, indicating a higher level of agreement on CT. The Dice coefficients were 89% for the stage IB2 case with a CR, 74% for the stage IIB case with a PR, and 57% for the stage IIB case with a CR. Conclusion: In a comparison of MR-contoured with CT-contoured CTV volumes, the higher level of agreement on CT may be due to the more distinct contrast medium visible on the images at the time of brachytherapy. MR at the time of brachytherapy may be of greatest benefit in patients with large tumors with parametrial extension that have a partial or complete response to external beam. On the basis of these results, a 95% consensus volume was generated for CT and for MR. Online contouring atlases are available for instruction at (http://www.nrgoncology.org/Resources/ContouringAtlases/GYNCervicalBrachytherapy.aspx)

  9. Influence of experience and qualification on PET-based target volume delineation. When there is no expert--ask your colleague.

    Science.gov (United States)

    Doll, C; Duncker-Rohr, V; Rücker, G; Mix, M; MacManus, M; De Ruysscher, D; Vogel, W; Eriksen, J G; Oyen, W; Grosu, A-L; Weber, W; Nestle, U

    2014-06-01

    The integration of positron emission tomography (PET) information for target volume delineation in radiation treatment planning is routine in many centers. In contrast to automatic contouring, research on visual-manual delineation is scarce. The present study investigates the dependency of manual delineation on experience and qualification. A total of 44 international interdisciplinary observers each defined a [(18)F]fluorodeoxyglucose (FDG)-PET based gross tumor volume (GTV) using the same PET/CT scan from a patient with lung cancer. The observers were "experts" (E; n = 3), "experienced interdisciplinary pairs" (EP; 9 teams of radiation oncologist (RO) + nuclear medicine physician (NP)), "single field specialists" (SFS; n = 13), and "students" (S; n = 10). Five automatic delineation methods (AM) were also included. Volume sizes and concordance indices within the groups (pCI) and relative to the experts (eCI) were calculated. E (pCI = 0.67) and EP (pCI = 0.53) showed a significantly higher agreement within the groups as compared to SFS (pCI = 0.43, p = 0.03, and p = 0.006). In relation to the experts, EP (eCI = 0.55) showed better concordance compared to SFS (eCI = 0.49) or S (eCI = 0.47). The intermethod variability of the AM (pCI = 0.44) was similar to that of SFS and S, showing poorer agreement with the experts (eCI = 0.35). The results suggest that interdisciplinary cooperation could be beneficial for consistent contouring. Joint delineation by a radiation oncologist and a nuclear medicine physician showed remarkable agreement and better concordance with the experts compared to other specialists. The relevant intermethod variability of the automatic algorithms underlines the need for further standardization and optimization in this field.

  10. Influence of experience and qualification on PET-based target volume delineation : When there is no expert-ask your colleague

    NARCIS (Netherlands)

    Doll, C.; Duncker-Rohr, V.; Rucker, G.; Mix, M.; Macmanus, M.; Ruysscher, D.D.; Vogel, W.; Eriksen, J.G.; Oyen, W.J.G.; Grosu, A.-L.; Weber, W.; Nestle, U.

    2014-01-01

    The integration of positron emission tomography (PET) information for target volume delineation in radiation treatment planning is routine in many centers. In contrast to automatic contouring, research on visual-manual delineation is scarce. The present study investigates the dependency of manual

  11. Determining optimal clinical target volume margins in head-and-neck cancer based on microscopic extracapsular extension of metastatic neck nodes

    International Nuclear Information System (INIS)

    Apisarnthanarax, Smith; Elliott, Danielle D.; El-Naggar, Adel K.; Asper, Joshua A. P.A.; Blanco, Angel; Ang, K. Kian; Garden, Adam S.; Morrison, William H.; Rosenthal, David; Weber, Randal S.; Chao, K.S. Clifford

    2006-01-01

    Purpose: To determine the optimal clinical target volume margins around the gross nodal tumor volume in head-and-neck cancer by assessing microscopic tumor extension beyond cervical lymph node capsules. Methods and Materials: Histologic sections of 96 dissected cervical lymph nodes with extracapsular extension (ECE) from 48 patients with head-and-neck squamous cell carcinoma were examined. The maximum linear distance from the external capsule border to the farthest extent of the tumor or tumoral reaction was measured. The trends of ECE as a function of the distance from the capsule and lymph node size were analyzed. Results: The median diameter of all lymph nodes was 11.0 mm (range: 3.0-30.0 mm). The mean and median ECE extent was 2.2 mm and 1.6 mm, respectively (range: 0.4-9.0 mm). The ECE was <5 mm from the capsule in 96% of the nodes. As the distance from the capsule increased, the probability of tumor extension declined. No significant difference between the extent of ECE and lymph node size was observed. Conclusion: For N1 nodes that are at high risk for ECE but not grossly infiltrating musculature, 1 cm clinical target volume margins around the nodal gross tumor volume are recommended to cover microscopic nodal extension in head-and-neck cancer

  12. Target volume geometric change and/or deviation from the cranium during fractionated stereotactic radiotherapy for brain metastases: potential pitfalls in image guidance based on bony anatomy alignment.

    Science.gov (United States)

    Ohtakara, Kazuhiro; Hoshi, Hiroaki

    2014-12-01

    This study sought to evaluate the potential geometrical change and/or displacement of the target relative to the cranium during fractionated stereotactic radiotherapy (FSRT) for treating newly developed brain metastases. For 16 patients with 21 lesions treated with image-guided frameless FSRT in 5 or 10 fractions using a 6-degree-of-freedom image guidance system-integrated platform, the unenhanced computed tomography or T2-weighted magnetic resonance images acquired until the completion of FSRT were fused to the planning image datasets for comparison. Significant change was defined as ≥3-mm change in the tumour diameter or displacement of the tumour centroid. FSRT was started 1 day after planning image acquisition. Tumour shrinkage, deviation and both were observed in 2, 1 and 1 of the 21 lesions, respectively, over a period of 7-13 days. Tumour shrinkage or deviation resulted in an increase or decrease in the marginal dose to the tumour, respectively, and a substantial increase in the irradiated volume for the surrounding tissue irrespective of the pattern of alteration. No obvious differences in the clinical and treatment characteristics were noted among the populations with or without significant changes in tumour volume or position. Target deformity and/or deviation can unexpectedly occur even during relatively short-course FSRT, inevitably leading to a gradual discrepancy between the planned and actually delivered doses to the tumour and surrounding tissue. To appropriately weigh the treatment outcome against the planned dose distribution, target deformity and/or deviation should also be considered in addition to the immobilisation accuracy, as image guidance with bony anatomy alignment does not necessarily guarantee accurate target localisation until completion of FSRT. © 2014 The Royal Australian and New Zealand College of Radiologists.

  13. Identifying radiotherapy target volumes in brain cancer by image analysis.

    Science.gov (United States)

    Cheng, Kun; Montgomery, Dean; Feng, Yang; Steel, Robin; Liao, Hanqing; McLaren, Duncan B; Erridge, Sara C; McLaughlin, Stephen; Nailon, William H

    2015-10-01

    To establish the optimal radiotherapy fields for treating brain cancer patients, the tumour volume is often outlined on magnetic resonance (MR) images, where the tumour is clearly visible, and mapped onto computerised tomography images used for radiotherapy planning. This process requires considerable clinical experience and is time consuming, which will continue to increase as more complex image sequences are used in this process. Here, the potential of image analysis techniques for automatically identifying the radiation target volume on MR images, and thereby assisting clinicians with this difficult task, was investigated. A gradient-based level set approach was applied on the MR images of five patients with grades II, III and IV malignant cerebral glioma. The relationship between the target volumes produced by image analysis and those produced by a radiation oncologist was also investigated. The contours produced by image analysis were compared with the contours produced by an oncologist and used for treatment. In 93% of cases, the Dice similarity coefficient was found to be between 60 and 80%. This feasibility study demonstrates that image analysis has the potential for automatic outlining in the management of brain cancer patients, however, more testing and validation on a much larger patient cohort is required.

  14. Target volumes in gastric cancer radiation therapy

    International Nuclear Information System (INIS)

    Caudry, M.; Maire, J.P.; Ratoanina, J.L.; Escarmant, P.

    2001-01-01

    The spread of gastric adenocarcinoma may follow three main patterns: hemato-genic, lymphatic and intraperitoneal. A GTV should be considered in preoperative or exclusive radiation therapy. After non-radical surgery, a 'residual GTV' will be defined with the help of the surgeon. The CTV encompasses three intricated volumes. a) A 'tumor bed' volume. After radical surgery, local recurrences appear as frequent as distant metastases. The risk depends upon the depth of parietal invasion and the nodal status. Parietal infiltration may extend beyond macroscopic limits of the tumor, especially in dinitis plastica. Therefore this volume will include: the tumor and the remaining stomach or their 'bed of resection', a part of the transverse colon, the duodenum, the pancreas and the troncus of the portal vein. In postoperative RT, this CTV also includes the jejuno-gastric or jejuno-esophageal anastomosis. b) A peritoneal volume. For practical purposes, two degrees of spread must be considered: (1) contiguous microscopic extension from deeply invasive T3 and T4 tumors, that remain amenable to local sterilization with doses of 45-50 Gy, delivered in a CTV including the peritoneal cavity at the level of the gastric bed, and under the parietal incision; (2) true 'peritoneal carcinomatosis', with widespread seeds, where chemotherapy (systemic or intraperitoneal) is more appropriate. c) A lymphatic volume including the lymph node groups 1 to 16 of the Japanese classification. This volume must encompass the hepatic pedicle and the splenic hilum. In proximal tumors, it is possible to restrict the lover part of the CTV to the lymphatic volume, and therefore to avoid irradiation of large intestinal and renal volumes. In distal and proximal tumors, involvement of resection margins is of poor prognosis -a radiation boost must be delivered at this level. The CTV in tumors of the cardia should encompass the lover part of the thoracic esophagus and the corresponding posterior mediastinum. In

  15. Design of 4D treatment planning target volumes

    International Nuclear Information System (INIS)

    Rietzel, Eike; Liu, Arthur K. Ph.D.; Doppke, Karen P.; Wolfgang, John A.; Chen, Aileen B.; Chen, George T.Y.; Choi, Noah C.

    2006-01-01

    Purpose: When using non-patient-specific treatment planning margins, respiratory motion may lead to geometric miss of the target while unnecessarily irradiating normal tissue. Imaging different respiratory states of a patient allows patient-specific target design. We used four-dimensional computed tomography (4DCT) to characterize tumor motion and create treatment volumes in 10 patients with lung cancer. These were compared with standard treatment volumes. Methods and Materials: Four-dimensional CT and free breathing helical CT data of 10 patients were acquired. Gross target volumes (GTV) were delineated on the helical scan as well as on each phase of the 4D data. Composite GTVs were defined on 4DCT. Planning target volumes (PTV) including clinical target volume, internal margin (IM), and setup margin were generated. 4DPTVs with different IMs and standard PTVs were compared by computing centroid positions, volumes, volumetric overlap, and bounding boxes. Results: Four-dimensional PTVs and conventional PTVs differed in volume and centroid positions. Overlap between 4DPTVs generated from two extreme tumor positions only compared with 10 respiratory phases was 93.7%. Comparing PTVs with margins of 15 mm (IM 5 mm) on composite 4D target volumes to PTVs with 20 mm (IM 10 mm) on helical CT data resulted in a decrease in target volume sizes by 23% on average. Conclusion: With patient-specific characterization of tumor motion, it should be possible to decrease internal margins. Patient-specific treatment volumes can be generated using extreme tumor positions on 4DCT. To date, more than 150 patients have been treated using 4D target design

  16. A method for mapping tissue volume model onto target volume using volumetric self-organizing deformable model

    Science.gov (United States)

    Miyauchi, Shoko; Morooka, Ken'ichi; Tsuji, Tokuo; Miyagi, Yasushi; Fukuda, Takaichi; Kurazume, Ryo

    2016-03-01

    This paper proposes a new method for mapping volume models of human tissues onto a target volume with simple shapes. The proposed method is based on our modified self-organizing deformable model (mSDM)1, 2 which finds the one-to-one mapping with no foldovers between arbitrary surface model and a target surface. By extending mSDM to apply to volume models, the proposed method, called volumetric SDM (vSDM), establishes the one-to-one correspondence between the tissue volume model and its target volume. At the same time, vSDM can preserve geometrical properties of the original model before and after mapping. This characteristic of vSDM makes it easy to find the correspondence between tissue models.

  17. SU-G-BRA-04: Simulation of Errors in Maximal Intensity Projection (MIP)-Based Lung Tumor Internal Target Volumes (ITV) Using Real-Time 2D MRI and Deformable Image Registration Based Lung Tumor Tracking

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, D; Kishan, A; Santhanam, A; Min, Y; O’Connell, D; Lamb, J; Cao, M; Agazaryan, N; Yang, Y; Lee, P; Low, D [University of California, Los Angeles, Ca (United States)

    2016-06-15

    Purpose: To evaluate the effect of inter- and intra-fractional tumor motion on the error in four-dimensional computed tomography (4DCT) maximal intensity projection (MIP)–based lung tumor internal target volumes (ITV), using deformable image registration of real-time 2D-sagital cine-mode MRI acquired during lung SBRT treatments. Methods: Five lung tumor patients underwent free breathing SBRT treatment on the ViewRay, with dose prescribed to PTV (4DCT MIP-based ITV+3–6mm margin). Sagittal slice cine-MR images (3.5×3.5mm pixels) were acquired through the center of the tumor at 4 frames per second throughout the treatments (3–4 fractions of 21–32 minutes duration). Tumor GTVs were contoured on the first frame of the cine and tracked throughout the treatment using off-line optical-flow based deformable registration implemented on a GPU cluster. Pseudo-4DCT MIP-based ITVs were generated from MIPs of the deformed GTV contours limited to short segments of image data. All possible pseudo-4DCT MIP-based ITV volumes were generated with 1s resolution and compared to the ITV volume of the entire treatment course. Varying pseudo-4DCT durations from 10-50s were analyzed. Results: Tumors were covered in their entirety by PTV in the patients analysed here. However, pseudo-4DCT based ITV volumes were observed that were as small as 29% of the entire treatment-ITV, depending on breathing irregularity and the duration of pseudo-4DCT. With an increase in duration of pseudo-4DCT from 10–50s the minimum volume acquired from 95% of all pseudo-4DCTs increased from 62%–81% of the treatment ITV. Conclusion: A 4DCT MIP-based ITV offers a ‘snap-shot’ of breathing motion for the brief period of time the tumor is imaged on a specific day. Real time MRI over prolonged periods of time and over multiple treatment fractions shows that the accuracy of this snap-shot varies according to inter- and intra-fractional tumor motion. Further work is required to investigate the dosimetric

  18. Investigating different computed tomography techniques for internal target volume definition

    Directory of Open Access Journals (Sweden)

    S A Yoganathan

    2017-01-01

    Conclusions: When comparing with 4DCT, all the CT techniques underestimated ITV. In the absence of 4DCT, the HF-CBCT target volumes with appropriate margin may be a reasonable approach for defining the ITV.

  19. Geometrical differences in target volumes based on 18F-fluorodeoxyglucose positron emission tomography/computed tomography and four-dimensional computed tomography maximum intensity projection images of primary thoracic esophageal cancer.

    Science.gov (United States)

    Guo, Y; Li, J; Wang, W; Zhang, Y; Wang, J; Duan, Y; Shang, D; Fu, Z

    2014-01-01

    The objective of the study was to compare geometrical differences of target volumes based on four-dimensional computed tomography (4DCT) maximum intensity projection (MIP) and 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) images of primary thoracic esophageal cancer for radiation treatment. Twenty-one patients with thoracic esophageal cancer sequentially underwent contrast-enhanced three-dimensional computed tomography (3DCT), 4DCT, and 18F-FDG PET/CT thoracic simulation scans during normal free breathing. The internal gross target volume defined as IGTVMIP was obtained by contouring on MIP images. The gross target volumes based on PET/CT images (GTVPET ) were determined with nine different standardized uptake value (SUV) thresholds and manual contouring: SUV≥2.0, 2.5, 3.0, 3.5 (SUVn); ≥20%, 25%, 30%, 35%, 40% of the maximum (percentages of SUVmax, SUVn%). The differences in volume ratio (VR), conformity index (CI), and degree of inclusion (DI) between IGTVMIP and GTVPET were investigated. The mean centroid distance between GTVPET and IGTVMIP ranged from 4.98 mm to 6.53 mm. The VR ranged from 0.37 to 1.34, being significantly (P<0.05) closest to 1 at SUV2.5 (0.94), SUV20% (1.07), or manual contouring (1.10). The mean CI ranged from 0.34 to 0.58, being significantly closest to 1 (P<0.05) at SUV2.0 (0.55), SUV2.5 (0.56), SUV20% (0.56), SUV25% (0.53), or manual contouring (0.58). The mean DI of GTVPET in IGTVMIP ranged from 0.61 to 0.91, and the mean DI of IGTVMIP in GTVPET ranged from 0.34 to 0.86. The SUV threshold setting of SUV2.5, SUV20% or manual contouring yields the best tumor VR and CI with internal-gross target volume contoured on MIP of 4DCT dataset, but 3DPET/CT and 4DCT MIP could not replace each other for motion encompassing target volume delineation for radiation treatment. © 2014 International Society for Diseases of the Esophagus.

  20. Target volume definition and target conformal irradiation technique for breast cancer patients

    Energy Technology Data Exchange (ETDEWEB)

    Kiricuta, I.C.; Gotz, U.; Schwab, F.; Fehn, M.; Neumann, H.H. [St. Vincenz-Hospital, Limburg (Germany). Inst. of Radiation Oncology

    2000-07-01

    The aim of this study was to present the target volume and irradiation technique in the most complex situation where the breast or chest wall and the locoregional lymphatics (mammarial internal lymph nodes, axillary and supraclavicular lymph nodes) have to be irradiated. The study comprised 125 breast cancer patients treated with curative intent after primary surgery in the last two years at our institute. In 62 cases the target volume included the breast or chest wall and the locoregional lymphatics, which were treated using our irradiation technique. The target conformal irradiation technique is a multiple non-opposed beams one isocenter technique developed to protect the heart and lungs. This technique, consisting of several rotation beams modulated with wedge filters and individual lung absorbers as well as additional fixed beams, was used in our study to apply a homogeneous dose of 46 to 56 Gy to the target volume; the irradiation technique was optimized by means of dose-volume histograms. After pre-localization, the patients underwent computerized tomographic scanning, with sections at 1.0 cm intervals. Contouring of target volume and organs at risk was carried out with a MULTIDATA workstation for regions of interest (mammarial internal and/or axillary and/or supraclavicular lymphatics and the breast or chest wall) as well as the organs at risk, such as heart and lung parenchyma. Planning target volume coverage was examined by three-dimensional isodose visualization for all CT axial sections for each patient. To determine the incidence of acute or late side effects on the lung parenchyma, conventional chest x-rays and CT studies were carried out at 1 month, 3 months and 6 months after completion of radiotherapy. Dose-volume histogram analysis revealed that this irradiation technique permits the application of a homogeneous dose to the target volume, conforming to the ICRU norms. The maximum dose applied to the ipsilateral lung parenchyma was less than 50

  1. Dictionary Based Segmentation in Volumes

    DEFF Research Database (Denmark)

    Emerson, Monica Jane; Jespersen, Kristine Munk; Jørgensen, Peter Stanley

    2015-01-01

    We present a method for supervised volumetric segmentation based on a dictionary of small cubes composed of pairs of intensity and label cubes. Intensity cubes are small image volumes where each voxel contains an image intensity. Label cubes are volumes with voxelwise probabilities for a given...... label. The segmentation process is done by matching a cube from the volume, of the same size as the dictionary intensity cubes, to the most similar intensity dictionary cube, and from the associated label cube we get voxel-wise label probabilities. Probabilities from overlapping cubes are averaged...... and hereby we obtain a robust label probability encoding. The dictionary is computed from labeled volumetric image data based on weighted clustering. We experimentally demonstrate our method using two data sets from material science – a phantom data set of a solid oxide fuel cell simulation for detecting...

  2. Octree-based Volume Sculpting

    DEFF Research Database (Denmark)

    Bærentzen, Jakob Andreas

    1998-01-01

    A volume sculpting system is presented. The system provides tools for interactive editing of a voxel raster that is stored in an octree data structure. Two different modes of sculpting are supported: Sculpting by adding and subtracting solids, and sculpting with tools that are based on a spray can...

  3. Prospective evaluation of early treatment outcome in patients with meningiomas treated with particle therapy based on target volume definition with MRI and {sup 68}Ga-DOTATOC-PET

    Energy Technology Data Exchange (ETDEWEB)

    Combs, Stephanie E.; Welzel, Thomas; Habermehl, Daniel; Rieken, Stefan; Dittmar, Jan-Oliver; Kessel, Kerstin; Debus, Juergen [Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany)], e-mail: Stephanie.Combs@med.uni-heidelberg.de; Jaekel, Oliver [Heidelberg Ion Therapy Center (HIT), Heidelberg (Germany); Haberkorn, Uwe [Univ. Hospital of Heidelberg, Dept. of Nuclear Medicine, Heidelberg (Germany)

    2013-04-15

    Purpose: To evaluate early treatment results and toxicity in patients with meningiomas treated with particle therapy. Material and methods: Seventy patients with meningiomas were treated with protons (n = 38) or carbon ion radiotherapy (n = 26). Median age was 49 years. Median age at treatment was 55 years, 24 were male (34%), and 46 were female (66%). Histology was benign meningioma in 26 patients (37%), atypical in 23 patients (33%) and anaplastic in four patients (6%). In 17 patients (24%) with skull base meningiomas diagnosis was based on the typical appearance of a meningioma. For benign meningiomas, total doses of 52.2-57.6 GyE were applied with protons. For high-grade lesions, the boost volume was 18 GyE carbon ions, with a median dose of 50 GyE applied as highly conformal radiation therapy. Nineteen patients were treated as re-irradiation. Treatment planning with MRI and 68-Ga-DOTATOC-PET was evaluated. Results: Very low rates of side effects developed, including headaches, nausea and dizziness. No severe treatment-related toxicity was observed. Local control for benign meningiomas was 100%. Five of 27 patients (19%) developed tumor recurrence during follow-up. Of these, four patients had been treated as re-irradiation for recurrent high-risk meningiomas. Actuarial local control after re-irradiation of high-risk meningiomas was therefore 67% at six and 12 months. In patients treated with primary radiotherapy, only one of 13 patients (8%) developed tumor recurrence 17 months after radiation therapy (photon and carbon ion boost). Conclusion: Continuous prospective follow-up and development of novel study concepts are required to fully exploit the long-term clinical data after particle therapy for meningiomas. To date, it may be concluded that when proton therapy is available, meningioma patients can be offered a treatment at least comparable to high-end photon therapy.

  4. Rectal cancer: The radiation basis of radiotherapy, target volume

    International Nuclear Information System (INIS)

    Bosset, J.F.; Servagi-Vernat, S.; Crehange, G.; Azria, D.; Gerard, J.P.; Hennequin, C.

    2011-01-01

    Since the implementation of preoperative chemo-radiotherapy and meso-rectal excision, the 5-year rates of locoregional failures in T3-T4 N0-N1M0 rectal cancer fell from 25-30% thirty years ago to 5-8% nowadays. A critical analysis of the locoregional failures sites and mechanisms, as well as the identification of nodal extension, helps the radiation oncologist to optimize the radiotherapy target definition. The upper limit of the clinical target volume is usually set at the top of the third sacral vertebra. The lateral pelvic nodes should be included when the tumor is located in the distal part of the rectum. The anal sphincter and the levator muscles should be spared when a conservative surgery is planned. In case of abdomino-perineal excision, the ischio-rectal fossa and the sphincters should be included in the clinical target volume. A confrontation with radiologist and surgeon is mandatory to improve the definition of the target volumes to be treated. (authors)

  5. Clinical target volume for rectal cancer. Preoperative radiotherapy

    International Nuclear Information System (INIS)

    Lorchel, F.; Bossel, J.F.; Baron, M.H.; Goubard, O.; Bartholomot, B.; Mantion, G.; Pelissier, E.P.; Maingon, P.

    2001-01-01

    The total meso-rectal excision allows the marked increase of the local control rate in rectal cancer. Therefore, the meso-rectal space is the usual field for the spread of rectal cancer cells. It could therefore be considered as the clinical target volume in the preoperative plan by the radiation oncologist. We propose to identify the mesorectum on anatomical structures of a treatment-position CT scan. (authors)

  6. Influence of experience and qualification on PET-based target volume delineation. When there is no expert--ask your colleague

    DEFF Research Database (Denmark)

    Doll, C; Duncker-Rohr, V; Rücker, G

    2014-01-01

    "experts" (E; n = 3), "experienced interdisciplinary pairs" (EP; 9 teams of radiation oncologist (RO) + nuclear medicine physician (NP)), "single field specialists" (SFS; n = 13), and "students" (S; n = 10). Five automatic delineation methods (AM) were also included. Volume sizes and concordance indices....... Joint delineation by a radiation oncologist and a nuclear medicine physician showed remarkable agreement and better concordance with the experts compared to other specialists. The relevant intermethod variability of the automatic algorithms underlines the need for further standardization...

  7. Target volumes in radiation therapy of childhood brain tumours

    International Nuclear Information System (INIS)

    Habrand, J.L.; Abdulkarim, B.; Beaudre, A.; El Khouri, M.; Kalifa, C.

    2001-01-01

    Pediatric tumors have enjoyed considerable improvements for the past 30 years. This is mainly due to the extensive use of combined therapeutical modalities in which chemotherapy plays a prominent role. In many children, local treatment including radiotherapy, can nowadays be adapted in terms of target volume and dose to the 'response' to an initial course of chemotherapy almost on a case by case basis. This makes precise recommendation on local therapy highly difficult in this age group. We will concentrate in this paper on brain tumors in which chemotherapy is of limited value and radiotherapy still plays a key-role. (authors)

  8. Target volume uncertainty and a method to visualize its effect on the target dose prescription

    International Nuclear Information System (INIS)

    McCormick, Traci; Dink, Delal; Orcun, Seza; Pekny, Joseph; Rardin, Ron; Baxter, Larry; Thai, Van; Langer, Mark

    2004-01-01

    Purpose: To consider the uncertainty in the construction of target boundaries for optimization, and to demonstrate how the principles of mathematical programming can be applied to determine and display the effect on the tumor dose of making small changes to the target boundary. Methods: The effect on the achievable target dose of making successive small shifts to the target boundary within its range of uncertainty was found by constructing a mixed-integer linear program that automated the placement of the beam angles using the initial target volume. Results: The method was demonstrated using contours taken from a nasopharynx case, with dose limits placed on surrounding structures. In the illustrated case, enlarging the target anteriorly to provide greater assurance of disease coverage did not force a sacrifice in the minimum or mean tumor doses. However, enlarging the margin posteriorly, near a critical structure, dramatically changed the minimum, mean, and maximum tumor doses. Conclusion: Tradeoffs between the position of the target boundary and the minimum target dose can be developed using mixed-integer programming, and the results projected as a guide to contouring and plan selection

  9. The effect of targeting scheme on tidal volume delivery during volume control mechanical ventilation.

    Science.gov (United States)

    Volsko, Teresa A; Hoffman, Justin; Conger, Alecia; Chatburn, Robert L

    2012-08-01

    Technological advances have increased ventilator mode complexity and risk of operator error. To compare differences in volume control (VC) ventilation with set-point and dual targeting. Two hypotheses were tested: tidal volume (V(T)) delivery is different with VC using set-point versus dual targeting during active versus passive breathing; VC with dual targeting delivers V(T) similar to pressure support ventilation (PS) with active breathing. The Ingmar Medical ASL 5000 lung model simulated pulmonary mechanics of an adult patient with ARDS during active and passive ventilation. Resistance was standardized at 10 cm H(2)O/L/s and compliance at 32 mL/cm H(2)O. Active breathing was simulated by setting the frequency (f) = 26 breaths/min, and adjusting the muscle pressure (P(mus)) to produce a V(T) of 384 mL. VC was initiated with the Puritan Bennett 840 (set-point targeting) and the Servo-i (dual targeting) at V(T) = 430 mL, mandatory f = 15 breaths/min, and PEEP = 10 cm H(2)O. During PS, cycle threshold was set to 30% and peak inspiratory pressure adjusted to produce a V(T) similar to that delivered during VC. Expiratory V(T) was collected on 10 consecutive breaths during active and passive breathing with VC and PS. Mean V(T) differences (active vs passive model) were compared using analysis of variance. Statistical significance was established at P targeting schemes: VC set-point = 37.3 ± 3.5 mL, VC-dual = 77.1 ± 3.3 mL, and PS = 406.1 ± 1.5 mL (P targeting during VC allows increased V(T), compared to set-point, but not as much as PS.

  10. Integration of three-dimensional magnetic resonance spectrometry to the irradiation treatment plan for glioblastomas: definition of new target volumes

    International Nuclear Information System (INIS)

    Ken, S.; Vieillevigne, L.; Cohen-Jonathan, E.M.; Laprie, A.; Ken, S.; Franceries, X.; Lotterie, J.A.; Lubrano, V.; Catalaa, I.; Celsis, P.; Berry, I.; Laprie, A.; Lotterie, J.A.; Lubrano, V.; Berry, I.; Catalaa, I.

    2010-01-01

    Based on a clinic trial, the authors report the definition of a new reliable and reproducible method to delimit and integrate targets to the treatment plan which are specific to magnetic resonance spectrometry imagery for the radiotherapy of glioblastomas, in order to perform a treatment by intensity-modulated conformational radiotherapy (IMRT). A weighted conventional MRI has been performed before radiotherapy. The importation of anatomic-metabolic images into the dose planning system comprises two steps: normalization on the whole volume of magnetic resonance spectrometry imagery, and segmentation of target volumes specific to spectrometry anomalies. This integration of target volumes is thus facilitated. Short communication

  11. Target Centroid Position Estimation of Phase-Path Volume Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Fengjun Hu

    2016-01-01

    Full Text Available For the problem of easily losing track target when obstacles appear in intelligent robot target tracking, this paper proposes a target tracking algorithm integrating reduced dimension optimal Kalman filtering algorithm based on phase-path volume integral with Camshift algorithm. After analyzing the defects of Camshift algorithm, compare the performance with the SIFT algorithm and Mean Shift algorithm, and Kalman filtering algorithm is used for fusion optimization aiming at the defects. Then aiming at the increasing amount of calculation in integrated algorithm, reduce dimension with the phase-path volume integral instead of the Gaussian integral in Kalman algorithm and reduce the number of sampling points in the filtering process without influencing the operational precision of the original algorithm. Finally set the target centroid position from the Camshift algorithm iteration as the observation value of the improved Kalman filtering algorithm to fix predictive value; thus to make optimal estimation of target centroid position and keep the target tracking so that the robot can understand the environmental scene and react in time correctly according to the changes. The experiments show that the improved algorithm proposed in this paper shows good performance in target tracking with obstructions and reduces the computational complexity of the algorithm through the dimension reduction.

  12. Control volume based hydrocephalus research

    Science.gov (United States)

    Cohen, Benjamin; Voorhees, Abram; Wei, Timothy

    2008-11-01

    Hydrocephalus is a disease involving excess amounts of cerebral spinal fluid (CSF) in the brain. Recent research has shown correlations to pulsatility of blood flow through the brain. However, the problem to date has presented as too complex for much more than statistical analysis and understanding. This talk will highlight progress on developing a fundamental control volume approach to studying hydrocephalus. The specific goals are to select physiologically control volume(s), develop conservation equations along with the experimental capabilities to accurately quantify terms in those equations. To this end, an in vitro phantom is used as a simplified model of the human brain. The phantom's design consists of a rigid container filled with a compressible gel. The gel has a hollow spherical cavity representing a ventricle and a cylindrical passage representing the aquaducts. A computer controlled piston pump supplies pulsatile volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity, and volume change as functions of time. Independent pressure measurements and flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients.

  13. Relapse patterns after radiochemotherapy of glioblastoma with FET PET-guided boost irradiation and simulation to optimize radiation target volume

    International Nuclear Information System (INIS)

    Piroth, Marc D.; Galldiks, Norbert; Pinkawa, Michael; Holy, Richard; Stoffels, Gabriele; Ermert, Johannes; Mottaghy, Felix M.; Shah, N. Jon; Langen, Karl-Josef; Eble, Michael J.

    2016-01-01

    O-(2-18 F-fluoroethyl)-L-tyrosine-(FET)-PET may be helpful to improve the definition of radiation target volumes in glioblastomas compared with MRI. We analyzed the relapse patterns in FET-PET after a FET- and MRI-based integrated-boost intensity-modulated radiotherapy (IMRT) of glioblastomas to perform an optimized target volume definition. A relapse pattern analysis was performed in 13 glioblastoma patients treated with radiochemotherapy within a prospective phase-II-study between 2008 and 2009. Radiotherapy was performed as an integrated-boost intensity-modulated radiotherapy (IB-IMRT). The prescribed dose was 72 Gy for the boost target volume, based on baseline FET-PET (FET-1) and 60 Gy for the MRI-based (MRI-1) standard target volume. The single doses were 2.4 and 2.0 Gy, respectively. Location and volume of recurrent tumors in FET-2 and MRI-2 were analyzed related to initial tumor, detected in baseline FET-1. Variable target volumes were created theoretically based on FET-1 to optimally cover recurrent tumor. The tumor volume overlap in FET and MRI was poor both at baseline (median 12 %; range 0–32) and at time of recurrence (13 %; 0–100). Recurrent tumor volume in FET-2 was localized to 39 % (12–91) in the initial tumor volume (FET-1). Over the time a shrinking (mean 12 (5–26) ml) and shifting (mean 6 (1–10 mm) of the resection cavity was seen. A simulated target volume based on active tumor in FET-1 with an additional safety margin of 7 mm around the FET-1 volume covered recurrent FET tumor volume (FET-2) significantly better than a corresponding target volume based on contrast enhancement in MRI-1 with a same safety margin of 7 mm (100 % (54–100) versus 85 % (0–100); p < 0.01). A simulated planning target volume (PTV), based on FET-1 and additional 7 mm margin plus 5 mm margin for setup-uncertainties was significantly smaller than the conventional, MR-based PTV applied in this study (median 160 (112–297) ml versus 231 (117–386) ml, p < 0

  14. Dictionary Based Segmentation in Volumes

    DEFF Research Database (Denmark)

    Emerson, Monica Jane; Jespersen, Kristine Munk; Jørgensen, Peter Stanley

    Method for supervised segmentation of volumetric data. The method is trained from manual annotations, and these annotations make the method very flexible, which we demonstrate in our experiments. Our method infers label information locally by matching the pattern in a neighborhood around a voxel ...... to a dictionary, and hereby accounts for the volume texture....

  15. Patterns of Primary Tumor Invasion and Regional Lymph Node Spread Based on Magnetic Resonance Imaging in Early-Stage Nasal NK/T-cell Lymphoma: Implications for Clinical Target Volume Definition and Prognostic Significance

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Run-Ye [Department of Radiation Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Liu, Kang [Department of Imaging Diagnosis, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Wang, Wei-Hu; Jin, Jing; Song, Yong-Wen; Wang, Shu-Lian; Liu, Yue-Ping; Ren, Hua; Fang, Hui; Liu, Qing-Feng; Yang, Yong; Chen, Bo; Qi, Shu-Nan; Lu, Ning-Ning; Tang, Yu; Tang, Yuan; Li, Ning [Department of Radiation Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Ouyang, Han [Department of Imaging Diagnosis, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Li, Ye-Xiong, E-mail: yexiong12@163.com [Department of Radiation Oncology, National Cancer Center/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China)

    2017-01-01

    Purpose: This study aimed to determine the pathways of primary tumor invasion (PTI) and regional lymph node (LN) spread based on magnetic resonance imaging (MRI) in early-stage nasal NK/T-cell lymphoma (NKTCL), to improve clinical target volume (CTV) delineation and evaluate the prognostic value of locoregional extension patterns. Methods and Materials: A total of 105 patients with newly diagnosed early-stage nasal NKTCL who underwent pretreatment MRI were retrospectively reviewed. All patients received radiation therapy with or without chemotherapy. Results: The incidences of PTI and regional LN involvement were 64.7% and 25.7%, respectively. Based on the incidence of PTI, involved sites surrounding the nasal cavity were classified into 3 risk subgroups: high-risk (>20%), intermediate-risk (5%-20%), and low-risk (<5%). The most frequently involved site was the nasopharynx (35.2%), followed by the maxillary (21.9%) and ethmoid (21.9%) sinuses. Local disease and regional LN spread followed an orderly pattern without LN skipping. The retropharyngeal nodes (RPNs) were most frequently involved (19.0%), followed by level II (11.4%). The 5-year overall survival (OS), progression-free survival (PFS), and locoregional control (LRC) rates for all patients were 72.8%, 65.2%, and 90.0%, respectively. The presence of PTI and regional LN involvement based on MRI significantly and negatively affected PFS and OS. Conclusions: Early-stage nasal NKTCL presents with a high incidence of PTI but a relatively low incidence of regional LN spread. Locoregional spread followed an orderly pattern, and PTI and regional LN spread are powerful prognostic factors for poorer survival outcomes. CTV reduction may be feasible for selected patients.

  16. Target volume for adjuvant radiotherapy after prostatectomy; Volume cible de la radiotherapie adjuvante apres prostatectomie

    Energy Technology Data Exchange (ETDEWEB)

    Bossi, A. [Institut Gustave-Roussy, Dept. de Radiotherapie, 94 - Villejuif (France)

    2007-11-15

    Although radical prostatectomy is an effective treatment for clinically localized prostate cancer, it fails in up to 20 to 40% of the cases. Local failure represents one of the possible patterns of relapse and is announced by detectable serum P.S.A. levels. Patients at high risk for local relapse have extra prostatic disease, positive surgical margins or seminal vesicles infiltration at pathology. Three recently published phase III randomized clinical trials have clearly shown that, for these patients, immediate adjuvant irradiation reduces the risk of progression. For patients undergoing postoperative irradiation the standardisation of the target volume definition and delineation is required because no general consensus exists on prostate bed definition. The Genito-Urinary Working Party of the Radiation Oncology Group of the European Organization for the Research and treatment of cancer (R.O.G. O.R.T.C.) has developed a set of Guidelines to assist radiotherapists in the contouring of target volumes for postoperative irradiation: a consensus has been reached on a set of recommendations that are proposed to the radiation oncologist community. Emphasis has been put on the optimal cooperation between the surgeon, the pathologist and the radiotherapist in the frame of a multidisciplinary approach. Data on the presence and on the localization of extra prostatic extension and on positive surgical margins must be used. Placement of metallic clips in the tumor bed is of great help in localizing fixed anatomical sites as the anastomosis. The goal of such a document is to reduce inter-observer variability in target delineation in the framework of future clinical trials. (author)

  17. More Accurate Definition of Clinical Target Volume Based on the Measurement of Microscopic Extensions of the Primary Tumor Toward the Uterus Body in International Federation of Gynecology and Obstetrics Ib-IIa Squamous Cell Carcinoma of the Cervix

    International Nuclear Information System (INIS)

    Xie, Wen-Jia; Wu, Xiao; Xue, Ren-Liang; Lin, Xiang-Ying; Kidd, Elizabeth A.; Yan, Shu-Mei; Zhang, Yao-Hong; Zhai, Tian-Tian; Lu, Jia-Yang; Wu, Li-Li; Zhang, Hao; Huang, Hai-Hua; Chen, Zhi-Jian; Li, De-Rui; Xie, Liang-Xi

    2015-01-01

    Purpose: To more accurately define clinical target volume for cervical cancer radiation treatment planning by evaluating tumor microscopic extension toward the uterus body (METU) in International Federation of Gynecology and Obstetrics stage Ib-IIa squamous cell carcinoma of the cervix (SCCC). Patients and Methods: In this multicenter study, surgical resection specimens from 318 cases of stage Ib-IIa SCCC that underwent radical hysterectomy were included. Patients who had undergone preoperative chemotherapy, radiation, or both were excluded from this study. Microscopic extension of primary tumor toward the uterus body was measured. The association between other pathologic factors and METU was analyzed. Results: Microscopic extension toward the uterus body was not common, with only 12.3% of patients (39 of 318) demonstrating METU. The mean (±SD) distance of METU was 0.32 ± 1.079 mm (range, 0-10 mm). Lymphovascular space invasion was associated with METU distance and occurrence rate. A margin of 5 mm added to gross tumor would adequately cover 99.4% and 99% of the METU in the whole group and in patients with lymphovascular space invasion, respectively. Conclusion: According to our analysis of 318 SCCC specimens for METU, using a 5-mm gross tumor volume to clinical target volume margin in the direction of the uterus should be adequate for International Federation of Gynecology and Obstetrics stage Ib-IIa SCCC. Considering the discrepancy between imaging and pathologic methods in determining gross tumor volume extent, we recommend a safer 10-mm margin in the uterine direction as the standard for clinical practice when using MRI for contouring tumor volume

  18. More accurate definition of clinical target volume based on the measurement of microscopic extensions of the primary tumor toward the uterus body in international federation of gynecology and obstetrics Ib-IIa squamous cell carcinoma of the cervix.

    Science.gov (United States)

    Xie, Wen-Jia; Wu, Xiao; Xue, Ren-Liang; Lin, Xiang-Ying; Kidd, Elizabeth A; Yan, Shu-Mei; Zhang, Yao-Hong; Zhai, Tian-Tian; Lu, Jia-Yang; Wu, Li-Li; Zhang, Hao; Huang, Hai-Hua; Chen, Zhi-Jian; Li, De-Rui; Xie, Liang-Xi

    2015-01-01

    To more accurately define clinical target volume for cervical cancer radiation treatment planning by evaluating tumor microscopic extension toward the uterus body (METU) in International Federation of Gynecology and Obstetrics stage Ib-IIa squamous cell carcinoma of the cervix (SCCC). In this multicenter study, surgical resection specimens from 318 cases of stage Ib-IIa SCCC that underwent radical hysterectomy were included. Patients who had undergone preoperative chemotherapy, radiation, or both were excluded from this study. Microscopic extension of primary tumor toward the uterus body was measured. The association between other pathologic factors and METU was analyzed. Microscopic extension toward the uterus body was not common, with only 12.3% of patients (39 of 318) demonstrating METU. The mean (±SD) distance of METU was 0.32 ± 1.079 mm (range, 0-10 mm). Lymphovascular space invasion was associated with METU distance and occurrence rate. A margin of 5 mm added to gross tumor would adequately cover 99.4% and 99% of the METU in the whole group and in patients with lymphovascular space invasion, respectively. According to our analysis of 318 SCCC specimens for METU, using a 5-mm gross tumor volume to clinical target volume margin in the direction of the uterus should be adequate for International Federation of Gynecology and Obstetrics stage Ib-IIa SCCC. Considering the discrepancy between imaging and pathologic methods in determining gross tumor volume extent, we recommend a safer 10-mm margin in the uterine direction as the standard for clinical practice when using MRI for contouring tumor volume. Copyright © 2015 Elsevier Inc. All rights reserved.

  19. More Accurate Definition of Clinical Target Volume Based on the Measurement of Microscopic Extensions of the Primary Tumor Toward the Uterus Body in International Federation of Gynecology and Obstetrics Ib-IIa Squamous Cell Carcinoma of the Cervix

    Energy Technology Data Exchange (ETDEWEB)

    Xie, Wen-Jia [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Wu, Xiao [Department of Pathology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Xue, Ren-Liang; Lin, Xiang-Ying [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Kidd, Elizabeth A. [Department of Radiation Oncology, Stanford University, Stanford, California (United States); Yan, Shu-Mei [Department of Pathology, Sun Yat-Sen University Cancer Center, Guangzhou, Guangdong Province (China); Zhang, Yao-Hong [Department of Radiation Oncology, Chaozhou Hospital of Chaozhou City, Guangdong Province (China); Zhai, Tian-Tian; Lu, Jia-Yang; Wu, Li-Li; Zhang, Hao [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Huang, Hai-Hua [Department of Pathology, The Second Affiliated Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Chen, Zhi-Jian; Li, De-Rui [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China); Xie, Liang-Xi, E-mail: xieliangxi1@qq.com [Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong Province (China)

    2015-01-01

    Purpose: To more accurately define clinical target volume for cervical cancer radiation treatment planning by evaluating tumor microscopic extension toward the uterus body (METU) in International Federation of Gynecology and Obstetrics stage Ib-IIa squamous cell carcinoma of the cervix (SCCC). Patients and Methods: In this multicenter study, surgical resection specimens from 318 cases of stage Ib-IIa SCCC that underwent radical hysterectomy were included. Patients who had undergone preoperative chemotherapy, radiation, or both were excluded from this study. Microscopic extension of primary tumor toward the uterus body was measured. The association between other pathologic factors and METU was analyzed. Results: Microscopic extension toward the uterus body was not common, with only 12.3% of patients (39 of 318) demonstrating METU. The mean (±SD) distance of METU was 0.32 ± 1.079 mm (range, 0-10 mm). Lymphovascular space invasion was associated with METU distance and occurrence rate. A margin of 5 mm added to gross tumor would adequately cover 99.4% and 99% of the METU in the whole group and in patients with lymphovascular space invasion, respectively. Conclusion: According to our analysis of 318 SCCC specimens for METU, using a 5-mm gross tumor volume to clinical target volume margin in the direction of the uterus should be adequate for International Federation of Gynecology and Obstetrics stage Ib-IIa SCCC. Considering the discrepancy between imaging and pathologic methods in determining gross tumor volume extent, we recommend a safer 10-mm margin in the uterine direction as the standard for clinical practice when using MRI for contouring tumor volume.

  20. Postoperative radiation in esophageal squamous cell carcinoma and target volume delineation

    Directory of Open Access Journals (Sweden)

    Zhu Y

    2016-07-01

    Full Text Available Yingming Zhu,* Minghuan Li,* Li Kong, Jinming Yu Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong, People’s Republic of China *These authors contributed equally to this work Abstract: Esophageal cancer is the sixth leading cause of cancer death worldwide, and patients who are treated with surgery alone, without neoadjuvant therapies, experience frequent relapses. Whether postoperative therapies could reduce the recurrence or improve overall survival is still controversial for these patients. The purpose of our review is to figure out the value of postoperative adjuvant therapy and address the disputes about target volume delineation according to published data. Based on the evidence of increased morbidity and disadvantages on patient survival caused by postoperative chemotherapy or radiotherapy (RT alone provided by studies in the early 1990s, the use of postoperative adjuvant therapies in cases of esophageal squamous cell carcinoma has diminished substantially and has been replaced gradually by neoadjuvant chemoradiation. With advances in surgery and RT, accumulating evidence has recently rekindled interest in the delivery of postoperative RT or chemoradiotherapy in patients with stage T3/T4 or N1 (lymph node positive carcinomas after radical surgery. However, due to complications with the standard radiation field, a nonconforming modified field has been adopted in most studies. Therefore, we analyze different field applications and provide suggestions on the optimization of the radiation field based on the major sites of relapse and the surgical non-clearance area. For upper and middle thoracic esophageal carcinomas, the bilateral supraclavicular and superior mediastinal areas remain common sites of recurrence and should be encompassed within the clinical target volume. In contrast, a consensus has yet to be reached regarding lower thoracic esophageal carcinomas; the

  1. Application of Advanced Functional Maps to the Radiation Treatment Plan for Biological Clinical Target Volumes

    International Nuclear Information System (INIS)

    Park, Ji Yeon; Jung, Won Gyun; Suh, Tae Suk; Lee, Jeong Woo; Ahn, Kook Jin

    2010-01-01

    Anatomical images including computerized tomography (CT) and T1-weighted magnetic resonance (T1-MR) images have been generally used to determine target volumes in radiation treatment plan (RTP). As only conventional images were referenced, tumors have tendency not to be enhanced by administrating agents depending on the tumor grade and patients. Recent advanced MR images, however, could guide physiologically and pathologically significant tumor characteristics. Furthermore, if the multi-functional images are employed, errors from using only one type of image will be complemented and distinct biological parameters can be applied as histological activity index. In this study, biological clinical target volumes (bCTVs) considered vascularity and cellularity can be determined based on multifunctional parametric maps using the in-house software for image registration and analysis. Using the developed software, rCBV and ADC maps were analyzed and bCTVs can be resolved considering vascularity and cellularity. In result, the bCTVs are exported on conventional images for biological RTP using image registration. Based on the multi-functional parametric maps of overlapped tumor regions, malignant sub-volumes can be determined. Multi-functional parametric maps would contribute to the detection of physiological and pathological tumor characteristics which are not be found in conventional images. They would reflect individual tumor biological characteristics to RTP for local tumor control.

  2. Technology transfer from NASA to targeted industries, volume 2

    Science.gov (United States)

    Mccain, Wayne; Schroer, Bernard J.; Souder, William E.; Spann, Mary S.; Watters, Harry; Ziemke, M. Carl

    1993-01-01

    This volume contains the following materials to support Volume 1: (1) Survey of Metal Fabrication Industry in Alabama; (2) Survey of Electronics Manufacturing/Assembly Industry in Alabama; (3) Apparel Modular Manufacturing Simulators; (4) Synopsis of a Stereolithography Project; (5) Transferring Modular Manufacturing Technology to an Apparel Firm; (6) Letters of Support; (7) Fact Sheets; (8) Publications; and (9) One Stop Access to NASA Technology Brochure.

  3. Multi-scenario based robust intensity-modulated proton therapy (IMPT) plans can account for set-up errors more effectively in terms of normal tissue sparing than planning target volume (PTV) based intensity-modulated photon plans in the head and neck region.

    Science.gov (United States)

    Stuschke, Martin; Kaiser, Andreas; Abu Jawad, Jehad; Pöttgen, Christoph; Levegrün, Sabine; Farr, Jonathan

    2013-06-18

    In a previous report, we compared the conformity of robust intensity-modulated proton therapy (IMPT) plans with that of helical tomotherapy plans for re-irradiations of head and neck carcinomas using a fixed set-up error of 2 mm. Here, we varied the maximum set-up errors between 0 and 5 mm and compared the robust IMPT-plans with planning target volume (PTV) based intensity-modulated photon therapy (IMRT). Seven patients were treated with a PTV-based tomotherapy plan. Set-up margins of 0, 2, and 5 mm were subtracted from the PTV to generate target volumes (TV) TV(0mm), TV(2mm), and TV(5mm), for which robust IMPT-plans were created assuming range uncertainties of ±3.5% and using worst case optimization assuming set-up errors of 0, 2, and 5 mm, respectively. Robust optimization makes use of the feature that set-up errors in beam direction alone do not affect the distal and proximal margin for that beam. With increasing set-up errors, the body volumes that were exposed to a selected minimum dose level between 20% and 95% of the prescribed dose decreased. In IMPT-plans with 0 mm set-up error, the exposed body volumes were on average 6.2% ± 0.9% larger than for IMPT-plans with 2 mm set-up error, independent of the considered dose level (p plans accounting for 5 mm set-up error, the exposed body volumes were by 11.9% ± 0.8% smaller than for IMPT-plans with 2 mm set-up error at a fixed minimum dose (p plans corresponding to the same IMRT-plan led to a decrease in the mean dose to the temporal lobes and the cerebellum, and in the D2% of the brain stem or spinal cord with increasing set-up errors considered during robust IMPT-planning. For recurrent head and neck cancer, robust IMPT-plan optimization led to a decrease in normal tissue exposure with increasing set-up error for target volumes corresponding to the same PTV.

  4. Delineation of Supraclavicular Target Volumes in Breast Cancer Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Lindsay C. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Diehn, Felix E. [Department of Radiology, Mayo Clinic, Rochester, Minnesota (United States); Boughey, Judy C. [Department of Surgery, Mayo Clinic, Rochester, Minnesota (United States); Childs, Stephanie K.; Park, Sean S.; Yan, Elizabeth S.; Petersen, Ivy A. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Mutter, Robert W., E-mail: mutter.robert@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2015-07-01

    Purpose: To map the location of gross supraclavicular metastases in patients with breast cancer, in order to determine areas at highest risk of harboring subclinical disease. Methods and Materials: Patients with axial imaging of gross supraclavicular disease were identified from an institutional breast cancer registry. Locations of the metastatic lymph nodes were transferred onto representative axial computed tomography images of the supraclavicular region and compared with the Radiation Therapy Oncology Group (RTOG) breast cancer atlas for radiation therapy planning. Results: Sixty-two patients with 161 supraclavicular nodal metastases were eligible for study inclusion. At the time of diagnosis, 117 nodal metastases were present in 44 patients. Forty-four nodal metastases in 18 patients were detected at disease recurrence, 4 of whom had received prior radiation to the supraclavicular fossa. Of the 161 nodal metastases, 95 (59%) were within the RTOG consensus volume, 4 nodal metastases (2%) in 3 patients were marginally within the volume, and 62 nodal metastases (39%) in 30 patients were outside the volume. Supraclavicular disease outside the RTOG consensus volume was located in 3 regions: at the level of the cricoid and thyroid cartilage (superior to the RTOG volume), in the posterolateral supraclavicular fossa (posterolateral to the RTOG volume), and in the lateral low supraclavicular fossa (lateral to the RTOG volume). Only women with multiple supraclavicular metastases had nodal disease that extended superiorly to the level of the thyroid cartilage. Conclusions: For women with risk of harboring subclinical supraclavicular disease warranting the addition of supraclavicular radiation, coverage of the posterior triangle and the lateral low supraclavicular region should be considered. For women with known supraclavicular disease, extension of neck coverage superior to the cricoid cartilage may be warranted.

  5. MLC tracking for lung SABR reduces planning target volumes and dose to organs at risk.

    Science.gov (United States)

    Caillet, Vincent; Keall, Paul J; Colvill, Emma; Hardcastle, Nicholas; O'Brien, Ricky; Szymura, Kathryn; Booth, Jeremy T

    2017-07-01

    Assess the dosimetric impact of multi-leaf collimator (MLC) tracking and mid-ventilation (midV) planning compared with the internal target volume (ITV)-based planning approach for lung Stereotactic Ablative Body Radiotherapy (SABR). Ten lung SABR patients originally treated with an ITV-based plan were re-planned according to MLC tracking and midV planning schemes. All plans were delivered on a linac to a motion phantom in a simulated treatment with real lung motions. Delivered dose was reconstructed in patient planning scans. ITV-based, tracking and midV regimes were compared at the planning and delivered stages based on PTV volume and dose metrics for the GTV and OAR. MLC tracking and midV schemes yielded favourable outcomes compared with ITV-based plans. Average reduction in PTV volume was (MLC tracking/MidV) 33.9%/22%. GTV dose coverage performed better with MLC tracking than the other regimes. Reduction in dose to OAR were for the lung (mean lung dose, 0.8Gy/0.2Gy), oesophagus (D3cc, 1.9Gy/1.4Gy), great vessels (D10cc, 3.2Gy/1.3Gy), trachea (D4cc, 1.1Gy/0.9Gy), heart (D1cc, 2.0Gy/0.5Gy) and spinal cord (D0.03cc, 0.5Gy/-0.1Gy). MLC tracking showed reduction in PTV volume, superior GTV dose coverage and organ dose sparing than MidV and ITV-based strategies. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Gastric irradiation for MALT lymphoma: Reducing the target volume, fast

    International Nuclear Information System (INIS)

    Wirth, A.; Teo, A.; Wittwer, H.; MacManus, M.; Ryan, G.

    1999-01-01

    A case of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma treated with radiotherapy alone is reported here. This case highlights treatment issues related to the variability in size and position of the stomach, and the substantial reduction in the size of the irradiated volume achieved by treating the patient in a fasting state. Copyright (1999) Blackwell Science Pty Ltd

  7. Nanotechnology based targeted drug delivery.

    Science.gov (United States)

    Ruggiero, Carmelina; Pastorino, Laura; Herrera, Oscar L

    2010-01-01

    NANOTECHNOLOGY is having a great impact on many industrial applications, such as manufacturing, semiconductors, nanostructured materials and biotechnology. As relates to the latter, nanobiotechnology focuses on the ability to work at the molecular and atomic level to fabricate structures combining biological materials and synthetic materials, taking into account engineering, physics, chemistry, genomics and proteomics. The main goals relate to biosensors, nanosized microchips, and more generally to medical applications at the molecular level. Nanotechnology has been recently extensively applied to treatment and diagnosis of diseases and the new term nanomedicine has been introduced, for which several definitions have so far been proposed [1]-[3] which focus on the use of engineered nano-devices and nanostructures for diagnosis and treatment. One of the key aspects of nanomedicine is targeted drug delivery by nanoscale drug carriers. At present, 95 % of all new potential therapeutics have poor pharmaco kinetics and biopharmaceutical properties, there is therefore a great need to develop drug delivery [4] systems that convey the therapeutically active molecules only to the site of action, without affecting other organs and tissues [5]. This allows to lower required doses of drugs and to increase their therapeutic indices and safety profiles. It is possible to fabricate nanoparticles or nanocapsules with different properties as relates to drug encapsulation and release. A great amount of nanoscale systems for drug delivery has been investigated; they include liposomes, dendrimers, quantum dots, nanotubes, polymeric biodegradable nanoparticles and nanocapsules [6].

  8. Gastric irradiation for MALT lymphoma: Reducing the target volume, fast

    Energy Technology Data Exchange (ETDEWEB)

    Wirth, A.; Teo, A.; Wittwer, H.; MacManus, M.; Ryan, G. [Peter MacCallum Cancer Institute, Melbourne, VIC (Australia). Departments of Radiation Oncology and Radiotherapy

    1999-02-01

    A case of low-grade gastric mucosa-associated lymphoid tissue (MALT) lymphoma treated with radiotherapy alone is reported here. This case highlights treatment issues related to the variability in size and position of the stomach, and the substantial reduction in the size of the irradiated volume achieved by treating the patient in a fasting state. Copyright (1999) Blackwell Science Pty Ltd 10 refs., 5 figs.

  9. Can FDG-PET assist in radiotherapy target volume definition of metastatic lymph nodes in head-and-neck cancer?

    NARCIS (Netherlands)

    Schinagl, D.A.X.; Hoffmann, A.L.; Vogel, W.V.; Dalen, J.A. van; Verstappen, S.M.M.; Oyen, W.J.G.; Kaanders, J.H.A.M.

    2009-01-01

    BACKGROUND AND PURPOSE: The role of FDG-PET in radiotherapy target volume definition of the neck was evaluated by comparing eight methods of FDG-PET segmentation to the current CT-based practice of lymph node assessment in head-and-neck cancer patients. MATERIALS AND METHODS: Seventy-eight

  10. Planning target volume (PTV) definition and its effects in the radiotherapy

    International Nuclear Information System (INIS)

    Poli, Maria Esmeralda Ramos

    2007-01-01

    Tills work intends to study the margins required to define a planning target volume (PTV) for adequate treatment of the mobile tumors such as prostate or those located in areas with less mobility as the ones in head and neck region, in the absence of daily localization imaging based. It is also intends to evaluate the impact caused by the PTV, in terms of dose, to the critical structures surrounding the PTV and its influence when inverse planning is used in the intensity-modulated radiation therapy (IMRT). Data from 387 prostate patients were analyzed retrospectively. Every patient in the study received daily pre-treatment localization with 2D ultrasound resulting in a total of 10,327 localizations, each comprising of an isocenter displacement in 3 directions: anterior-posterior (AP), right-left lateral (RL), and superior-inferior (SI). The mean displacement and standard deviation (SD) for each direction for each patient was computed from daily treatment records. The uncertainties (SD) in the target position were 4.4 mm (AP), 3.6 mm (RL), and 4.5 mm (SI). A study of the uncertainties in the daily positioning of 78 head and neck patients who used thermoplastic mask to immobilize them, evaluated with electronic portal imaging device (EPID), showed variations (SD) in the isocenter treatment position of 3.1 mm (AP), 1.5 mm (RL), and 4.5 mm (SI). By applying these shifts in an anthropomorphic phantom it was studied the dose-volume histograms resultant of the isocenter displacement in the daily treatment. The result showed the importance of putting margins in the clinical target volume to assure an adequate treatment and also showed that isocenter daily variation can cause an increase to the dose greater than the tolerance level to the critical organs. (author)

  11. Prostate bed target interfractional motion using RTOG consensus definitions and daily CT on rails. Does target motion differ between superior and inferior portions of the clinical target volume

    International Nuclear Information System (INIS)

    Verma, Vivek; Zhou, Sumin; Enke, Charles A.; Wahl, Andrew O.; Chen, Shifeng

    2017-01-01

    Using high-quality CT-on-rails imaging, the daily motion of the prostate bed clinical target volume (PB-CTV) based on consensus Radiation Therapy Oncology Group (RTOG) definitions (instead of surgical clips/fiducials) was studied. It was assessed whether PB motion in the superior portion of PB-CTV (SUP-CTV) differed from the inferior PB-CTV (INF-CTV). Eight pT2-3bN0-1M0 patients underwent postprostatectomy intensity-modulated radiotherapy, totaling 300 fractions. INF-CTV and SUP-CTV were defined as PB-CTV located inferior and superior to the superior border of the pubic symphysis, respectively. Daily pretreatment CT-on-rails images were compared to the planning CT in the left-right (LR), superoinferior (SI), and anteroposterior (AP) directions. Two parameters were defined: ''total PB-CTV motion'' represented total shifts from skin tattoos to RTOG-defined anatomic areas; ''PB-CTV target motion'' (performed for both SUP-CTV and INF-CTV) represented shifts from bone to RTOG-defined anatomic areas (i. e., subtracting shifts from skin tattoos to bone). Mean (± standard deviation, SD) total PB-CTV motion was -1.5 (± 6.0), 1.3 (± 4.5), and 3.7 (± 5.7) mm in LR, SI, and AP directions, respectively. Mean (± SD) PB-CTV target motion was 0.2 (±1.4), 0.3 (±2.4), and 0 (±3.1) mm in the LR, SI, and AP directions, respectively. Mean (± SD) INF-CTV target motion was 0.1 (± 2.8), 0.5 (± 2.2), and 0.2 (± 2.5) mm, and SUP-CTV target motion was 0.3 (± 1.8), 0.5 (± 2.3), and 0 (± 5.0) mm in LR, SI, and AP directions, respectively. No statistically significant differences between INF-CTV and SUP-CTV motion were present in any direction. There are no statistically apparent motion differences between SUP-CTV and INF-CTV. Current uniform planning target volume (PTV) margins are adequate to cover both portions of the CTV. (orig.) [de

  12. Exploring model-based target discrimination metrics

    Science.gov (United States)

    Witus, Gary; Weathersby, Marshall

    2004-08-01

    Visual target discrimination has occurred when the observer can say "I see a target THERE!" and can designate the target location. Target discrimination occurs when a perceived shape is sufficiently similar one or more of the instances the observer has been trained on. Marr defined vision as "knowing what is where by seeing." Knowing "what" requires prior knowledge. Target discrimination requires model-based visual processing. Model-based signature metrics attempt to answer the question "to what extent does the target in the image resemble a training image?" Model-based signature metrics attempt to represent the effects of high-level top-down visual cognition, in addition to low-level bottom-up effects. Recent advances in realistic 3D target rendering and computer-vision object recognition have made model-based signature metrics more practical. The human visual system almost certainly does NOT use the same processing algorithms as computer vision object recognition, but some processing elements and the overall effects are similar. It remains to be determined whether model-based metrics explain the variance in human performance. The purpose of this paper is to explain and illustrate the model-based approach to signature metrics.

  13. A general methodology for three-dimensional analysis of variation in target volume delineation

    NARCIS (Netherlands)

    Remeijer, P.; Rasch, C.; Lebesque, J. V.; van Herk, M.

    1999-01-01

    A generic method for three-dimensional (3-D) evaluation of target volume delineation in multiple imaging modalities is presented. The evaluation includes geometrical and statistical methods to estimate observer differences and variability in defining the Gross Tumor Volume (GTV) in relation to the

  14. Technology transfer from NASA to targeted industries, volume 1

    Science.gov (United States)

    Mccain, Wayne; Schroer, Bernard J.; Souder, William E.; Spann, Mary S.; Watters, Harry; Ziemke, M. Carl

    1993-01-01

    This report summarizes the University of Alabama in Huntsville (UAH) technology transfer to three target industries with focus on the apparel manufacturing industry in Alabama. Also included in this report are an analysis of the 1992 problem statements submitted by Alabama firms, the results of the survey of 1987-88 NASA Tech Brief requests, the results of the followup to Alabama submitted problem statements, and the development of the model describing the MSFC technology transfer process.

  15. Radial displacement of clinical target volume in node negative head and neck cancer

    International Nuclear Information System (INIS)

    Jeon, Wan; Wu, Hong Gyun; Song, Sang Hyuk; Kim, Jung In

    2012-01-01

    To evaluate the radial displacement of clinical target volume in the patients with node negative head and neck (H and N) cancer and to quantify the relative positional changes compared to that of normal healthy volunteers. Three node-negative H and N cancer patients and fi ve healthy volunteers were enrolled in this study. For setup accuracy, neck thermoplastic masks and laser alignment were used in each of the acquired computed tomography (CT) images. Both groups had total three sequential CT images in every two weeks. The lymph node (LN) level of the neck was delineated based on the Radiation Therapy Oncology Group (RTOG) consensus guideline by one physician. We use the second cervical vertebra body as a reference point to match each CT image set. Each of the sequential CT images and delineated neck LN levels were fused with the primary image, then maximal radial displacement was measured at 1.5 cm intervals from skull base (SB) to caudal margin of LN level V, and the volume differences at each node level were quantified. The mean radial displacements were 2.26 (±1.03) mm in the control group and 3.05 (±1.97) in the H and N cancer patients. There was a statistically significant difference between the groups in terms of the mean radial displacement (p = 0.03). In addition, the mean radial displacement increased with the distance from SB. As for the mean volume differences, there was no statistical significance between the two groups. This study suggests that a more generous radial margin should be applied to the lower part of the neck LN for better clinical target coverage and dose delivery.

  16. Radial displacement of clinical target volume in node negative head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Wan; Wu, Hong Gyun; Song, Sang Hyuk; Kim, Jung In [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    2012-03-15

    To evaluate the radial displacement of clinical target volume in the patients with node negative head and neck (H and N) cancer and to quantify the relative positional changes compared to that of normal healthy volunteers. Three node-negative H and N cancer patients and fi ve healthy volunteers were enrolled in this study. For setup accuracy, neck thermoplastic masks and laser alignment were used in each of the acquired computed tomography (CT) images. Both groups had total three sequential CT images in every two weeks. The lymph node (LN) level of the neck was delineated based on the Radiation Therapy Oncology Group (RTOG) consensus guideline by one physician. We use the second cervical vertebra body as a reference point to match each CT image set. Each of the sequential CT images and delineated neck LN levels were fused with the primary image, then maximal radial displacement was measured at 1.5 cm intervals from skull base (SB) to caudal margin of LN level V, and the volume differences at each node level were quantified. The mean radial displacements were 2.26 ({+-}1.03) mm in the control group and 3.05 ({+-}1.97) in the H and N cancer patients. There was a statistically significant difference between the groups in terms of the mean radial displacement (p = 0.03). In addition, the mean radial displacement increased with the distance from SB. As for the mean volume differences, there was no statistical significance between the two groups. This study suggests that a more generous radial margin should be applied to the lower part of the neck LN for better clinical target coverage and dose delivery.

  17. WTS - Risk Based Resource Targeting (RBRT) -

    Data.gov (United States)

    Department of Transportation — The Risk Based Resource Targeting (RBRT) application supports a new SMS-structured process designed to focus on safety oversight of systems and processes rather than...

  18. Localization Accuracy of the Clinical Target Volume During Image-Guided Radiotherapy of Lung Cancer

    International Nuclear Information System (INIS)

    Hugo, Geoffrey D.; Weiss, Elisabeth; Badawi, Ahmed; Orton, Matthew

    2011-01-01

    Purpose: To evaluate the position and shape of the originally defined clinical target volume (CTV) over the treatment course, and to assess the impact of gross tumor volume (GTV)-based online computed tomography (CT) guidance on CTV localization accuracy. Methods and Materials: Weekly breath-hold CT scans were acquired in 17 patients undergoing radiotherapy. Deformable registration was used to propagate the GTV and CTV from the first weekly CT image to all other weekly CT images. The on-treatment CT scans were registered rigidly to the planning CT scan based on the GTV location to simulate online guidance, and residual error in the CTV centroids and borders was calculated. Results: The mean GTV after 5 weeks relative to volume at the beginning of treatment was 77% ± 20%, whereas for the prescribed CTV, it was 92% ± 10%. The mean absolute residual error magnitude in the CTV centroid position after a GTV-based localization was 2.9 ± 3.0 mm, and it varied from 0.3 to 20.0 mm over all patients. Residual error of the CTV centroid was associated with GTV regression and anisotropy of regression during treatment (p = 0.02 and p = 0.03, respectively; Spearman rank correlation). A residual error in CTV border position greater than 2 mm was present in 77% of patients and 50% of fractions. Among these fractions, residual error of the CTV borders was 3.5 ± 1.6 mm (left-right), 3.1 ± 0.9 mm (anterior-posterior), and 6.4 ± 7.5 mm (superior-inferior). Conclusions: Online guidance based on the visible GTV produces substantial error in CTV localization, particularly for highly regressing tumors. The results of this study will be useful in designing margins for CTV localization or for developing new online CTV localization strategies.

  19. Delineation of Internal Mammary Nodal Target Volumes in Breast Cancer Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Jethwa, Krishan R.; Kahila, Mohamed M. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Hunt, Katie N. [Department of Radiology, Mayo Clinic, Rochester, Minnesota (United States); Brown, Lindsay C.; Corbin, Kimberly S.; Park, Sean S.; Yan, Elizabeth S. [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States); Boughey, Judy C. [Department of Surgery, Mayo Clinic, Rochester, Minnesota (United States); Mutter, Robert W., E-mail: mutter.robert@mayo.edu [Department of Radiation Oncology, Mayo Clinic, Rochester, Minnesota (United States)

    2017-03-15

    Purpose: The optimal clinical target volume for internal mammary (IM) node irradiation is uncertain in an era of increasingly conformal volume-based treatment planning for breast cancer. We mapped the location of gross internal mammary lymph node (IMN) metastases to identify areas at highest risk of harboring occult disease. Methods and Materials: Patients with axial imaging of IMN disease were identified from a breast cancer registry. The IMN location was transferred onto the corresponding anatomic position on representative axial computed tomography images of a patient in the treatment position and compared with consensus group guidelines of IMN target delineation. Results: The IMN location in 67 patients with 130 IMN metastases was mapped. The location was in the first 3 intercostal spaces in 102 of 130 nodal metastases (78%), whereas 18 of 130 IMNs (14%) were located caudal to the third intercostal space and 10 of 130 IMNs (8%) were located cranial to the first intercostal space. Of the 102 nodal metastases within the first 3 intercostal spaces, 54 (53%) were located within the Radiation Therapy Oncology Group consensus volume. Relative to the IM vessels, 19 nodal metastases (19%) were located medially with a mean distance of 2.2 mm (SD, 2.9 mm) whereas 29 (28%) were located laterally with a mean distance of 3.6 mm (SD, 2.5 mm). Ninety percent of lymph nodes within the first 3 intercostal spaces would have been encompassed within a 4-mm medial and lateral expansion on the IM vessels. Conclusions: In women with indications for elective IMN irradiation, a 4-mm medial and lateral expansion on the IM vessels may be appropriate. In women with known IMN involvement, cranial extension to the confluence of the IM vein with the brachiocephalic vein with or without caudal extension to the fourth or fifth interspace may be considered provided that normal tissue constraints are met.

  20. Delineation of Internal Mammary Nodal Target Volumes in Breast Cancer Radiation Therapy.

    Science.gov (United States)

    Jethwa, Krishan R; Kahila, Mohamed M; Hunt, Katie N; Brown, Lindsay C; Corbin, Kimberly S; Park, Sean S; Yan, Elizabeth S; Boughey, Judy C; Mutter, Robert W

    2017-03-15

    The optimal clinical target volume for internal mammary (IM) node irradiation is uncertain in an era of increasingly conformal volume-based treatment planning for breast cancer. We mapped the location of gross internal mammary lymph node (IMN) metastases to identify areas at highest risk of harboring occult disease. Patients with axial imaging of IMN disease were identified from a breast cancer registry. The IMN location was transferred onto the corresponding anatomic position on representative axial computed tomography images of a patient in the treatment position and compared with consensus group guidelines of IMN target delineation. The IMN location in 67 patients with 130 IMN metastases was mapped. The location was in the first 3 intercostal spaces in 102 of 130 nodal metastases (78%), whereas 18 of 130 IMNs (14%) were located caudal to the third intercostal space and 10 of 130 IMNs (8%) were located cranial to the first intercostal space. Of the 102 nodal metastases within the first 3 intercostal spaces, 54 (53%) were located within the Radiation Therapy Oncology Group consensus volume. Relative to the IM vessels, 19 nodal metastases (19%) were located medially with a mean distance of 2.2 mm (SD, 2.9 mm) whereas 29 (28%) were located laterally with a mean distance of 3.6 mm (SD, 2.5 mm). Ninety percent of lymph nodes within the first 3 intercostal spaces would have been encompassed within a 4-mm medial and lateral expansion on the IM vessels. In women with indications for elective IMN irradiation, a 4-mm medial and lateral expansion on the IM vessels may be appropriate. In women with known IMN involvement, cranial extension to the confluence of the IM vein with the brachiocephalic vein with or without caudal extension to the fourth or fifth interspace may be considered provided that normal tissue constraints are met. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. Impact of Node Negative Target Volume Delineation on Contralateral Parotid Gland Dose Sparing Using IMRT in Head and Neck Cancer.

    Science.gov (United States)

    Magnuson, William J; Urban, Erich; Bayliss, R Adam; Harari, Paul M

    2015-06-01

    There is considerable practice variation in treatment of the node negative (N0) contralateral neck in patients with head and neck cancer. In this study, we examined the impact of N0 neck target delineation volume on radiation dose to the contralateral parotid gland. Following institutional review board approval, 12 patients with head and neck cancer were studied. All had indications for treatment of the N0 neck, such as midline base of tongue or soft palate extension or advanced ipsilateral nodal disease. The N0 neck volumes were created using the Radiation Therapy Oncology Group head and neck contouring atlas. The physician-drawn N0 neck clinical target volume (CTV) was expanded by 25% to 200% to generate volume variation, followed by a 3-mm planning target volume (PTV) expansion. Surrounding organs at risk were contoured and complete intensity-modulated radiation therapy plans were generated for each N0 volume expansion. The median N0 target volume drawn by the radiation oncologist measured 93 cm(3) (range 71-145). Volumetric expansion of the N0 CTV by 25% to 200% increased the resultant mean dose to the contralateral parotid gland by 1.4 to 8.5 Gray (Gy). For example, a 4.1-mm increase in the N0 neck CTV translated to a 2.0-Gy dose increase to the parotid, 7.4 mm to a 4.5 Gy dose increase, and 12.5 mm to an 8.5 Gy dose increase, respectively. The treatment volume designated for the N0 neck has profound impact on resultant dose to the contralateral parotid gland. Variations of up to 15 mm are routine across physicians in target contouring, reflecting individual preference and training expertise. Depending on the availability of immobilization and image guidance techniques, experts commonly recommend 3 to 10 mm margin expansions to generate the PTV. Careful attention to the original volume of the N0 neck CTV, as well as expansion margins, is important in achieving effective contralateral gland sparing to reduce the resultant xerostomia and dysguesia that may ensue

  2. Postoperative radiotherapy for glioma: improved delineation of the clinical target volume using the geodesic distance calculation.

    Directory of Open Access Journals (Sweden)

    DanFang Yan

    Full Text Available OBJECTS: To introduce a new method for generating the clinical target volume (CTV from gross tumor volume (GTV using the geodesic distance calculation for glioma. METHODS: One glioblastoma patient was enrolled. The GTV and natural barriers were contoured on each slice of the computer tomography (CT simulation images. Then, a graphic processing unit based on a parallel Euclidean distance transform was used to generate the CTV considering natural barriers. Three-dimensional (3D visualization technique was applied to show the delineation results. Speed of operation and precision were compared between this new delineation method and the traditional method. RESULTS: In considering spatial barriers, the shortest distance from the point sheltered from these barriers equals the sum of the distance along the shortest path between the two points; this consists of several segments and evades the spatial barriers, rather than being the direct Euclidean distance between two points. The CTV was generated irregularly rather than as a spherical shape. The time required to generate the CTV was greatly reduced. Moreover, this new method improved inter- and intra-observer variability in defining the CTV. CONCLUSIONS: Compared with the traditional CTV delineation, this new method using geodesic distance calculation not only greatly shortens the time to modify the CTV, but also has better reproducibility.

  3. Inverse treatment planning using volume-based objective functions

    Science.gov (United States)

    Bednarz, Greg; Michalski, Darek; Anne, Pramila R.; Valicenti, Richard K.

    2004-06-01

    The results of optimization of inverse treatment plans depend on a choice of the objective function. Even when the optimal solution for a given cost function can be obtained, a better solution may exist for a given clinical scenario and it could be obtained with a revised objective function. In the approach presented in this work mixed integer programming was used to introduce a new volume-based objective function, which allowed for minimization of the number of under- or overdosed voxels in selected structures. By selecting and prioritizing components of this function the user could drive the computations towards the desired solution. This optimization approach was tested using cases of patients treated for prostate and oropharyngeal cancer. Initial solutions were obtained based on minimization/maximization of the dose to critical structures and targets. Subsequently, the volume-based objective functions were used to locate solutions, which satisfied better clinical objectives particular to each of the cases. For prostate cases, these additional solutions offered further improvements in sparing of the rectum or the bladder. For oropharyngeal cases, families of solutions were obtained satisfying an intensity modulated radiation therapy protocol for this disease site, while offering significant improvement in the sparing of selected critical structures, e.g., parotid glands. An additional advantage of the present approach was in providing a convenient mechanism to test the feasibility of the dose-volume histogram constraints.

  4. Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: a 'Big Brother' evaluation.

    NARCIS (Netherlands)

    Steenbakkers, R.J.; Duppen, J.C.; Fitton, I.; Deurloo, K.E.; Zijp, L.; Uitterhoeve, A.L.; Rodrigus, P.T.; Kramer, G.W.P.M.; Bussink, J.; Jaeger, K. de; Belderbos, J.S.; Hart, A.A.M.; Nowak, P.J.; Herk, M. van; Rasch, C.R.

    2005-01-01

    BACKGROUND AND PURPOSE: To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. PATIENTS AND METHODS: Eleven radiation oncologists (observers) from five different institutions delineated the Gross Tumor Volume

  5. Proton therapy of iris melanoma with 50 CGE. Influence of target volume on clinical outcome

    Energy Technology Data Exchange (ETDEWEB)

    Riechardt, Aline I.; Joussen, Antonia M. [Charite University of Medicine, Department of Ophthalmology, Berlin (Germany); Karle, Bettina [Helios Klinikum Emil-von-Behring, Department of Radiation Oncology, Berlin (Germany); Cordini, Dino; Heufelder, Jens [Charite University of Medicine, Department of Ophthalmology, Berlin (Germany); Helmholtz-Zentrum Berlin, Lise-Meitner-Campus, Berlin-Protonen, Berlin (Germany); Budach, Volker [Charite University of Medicine, Department of Radiation Oncology, Berlin (Germany); Gollrad, Johannes [Helmholtz-Zentrum Berlin, Lise-Meitner-Campus, Berlin-Protonen, Berlin (Germany); Charite University of Medicine, Department of Radiation Oncology, Berlin (Germany)

    2017-11-15

    The aim of this study was to evaluate local tumour control, incidence of radiation-induced glaucoma and associated interventions of sector-based and whole anterior segment proton beam therapy (PBT) for the treatment of iris melanoma. We retrospectively analysed the data of 77 patients with iris melanoma who underwent PBT applied as 50 CGE in four daily fractions. Of the patients, 47 received PBT with a circular-shaped collimator and 30 with a conformal sector-shaped target volume. Local control, eye preservation and secondary glaucoma were evaluated. Median follow-up time was 54.9 months. Local tumour control was 100% in patients receiving whole anterior segment irradiation. Two patients developed pigment dispersion in the non-irradiated area after sector-based PBT and received whole anterior segment salvage PBT. The mean volume of ciliary body irradiated was 89.0% and 34.9% for whole anterior segment and lesion-based irradiation, respectively. At the end of follow-up, secondary glaucoma was found in 74.3% of the patients with whole anterior segment irradiation and in 19.2% with sector-based irradiation. Patients with sector-based PBT had a stable visual acuity of logMAR 0.1, while it declined from logMAR 0.1 to 0.4 after whole anterior segment irradiation. We found a significant reduction in radiation-induced secondary glaucoma and glaucoma-associated surgical interventions and stable visual acuity after sector-based irradiation compared with whole anterior segment irradiation. Sector-based irradiation revealed a higher risk for local recurrence, but selected patients with well-circumscribed iris melanoma benefit from applying a lesion-based target volume when treated with sector-based PBT. (orig.) [German] Ziel der Arbeit war es, nach Irismelanomtherapie durch sektorielle oder Ganzfeldbestrahlung mittels Protonentherapie mit 50 CGE (Cobalt-Gray-Aequivalent) Tumorkontrolle, Inzidenz des strahleninduzierten Glaukoms und damit assoziierte Interventionen auszuwerten

  6. Volume-Targeted Ventilation in the Neonate: Benchmarking Ventilators on an Active Lung Model.

    Science.gov (United States)

    Krieger, Tobias J; Wald, Martin

    2017-03-01

    Mechanically ventilated neonates have been observed to receive substantially different ventilation after switching ventilator models, despite identical ventilator settings. This study aims at establishing the range of output variability among 10 neonatal ventilators under various breathing conditions. Relative benchmarking test of 10 neonatal ventilators on an active neonatal lung model. Neonatal ICU. Ten current neonatal ventilators. Ventilators were set identically to flow-triggered, synchronized, volume-targeted, pressure-controlled, continuous mandatory ventilation and connected to a neonatal lung model. The latter was configured to simulate three patients (500, 1,500, and 3,500 g) in three breathing modes each (passive breathing, constant active breathing, and variable active breathing). Averaged across all weight conditions, the included ventilators delivered between 86% and 110% of the target tidal volume in the passive mode, between 88% and 126% during constant active breathing, and between 86% and 120% under variable active breathing. The largest relative deviation occurred during the 500 g constant active condition, where the highest output machine produced 147% of the tidal volume of the lowest output machine. All machines deviate significantly in volume output and ventilation regulation. These differences depend on ventilation type, respiratory force, and patient behavior, preventing the creation of a simple conversion table between ventilator models. Universal neonatal tidal volume targets for mechanical ventilation cannot be transferred from one ventilator to another without considering necessary adjustments.

  7. Clinicopathologic Analysis of Microscopic Extension in Lung Adenocarcinoma: Defining Clinical Target Volume for Radiotherapy

    International Nuclear Information System (INIS)

    Grills, Inga S.; Fitch, Dwight L.; Goldstein, Neal S.; Yan Di; Chmielewski, Gary W.; Welsh, Robert J.; Kestin, Larry L.

    2007-01-01

    Purpose: To determine the gross tumor volume (GTV) to clinical target volume margin for non-small-cell lung cancer treatment planning. Methods: A total of 35 patients with Stage T1N0 adenocarcinoma underwent wedge resection plus immediate lobectomy. The gross tumor size and microscopic extension distance beyond the gross tumor were measured. The nuclear grade and percentage of bronchoalveolar features were analyzed for association with microscopic extension. The gross tumor dimensions were measured on a computed tomography (CT) scan (lung and mediastinal windows) and compared with the pathologic dimensions. The potential coverage of microscopic extension for two different lung stereotactic radiotherapy regimens was evaluated. Results: The mean microscopic extension distance beyond the gross tumor was 7.2 mm and varied according to grade (10.1, 7.0, and 3.5 mm for Grade 1 to 3, respectively, p < 0.01). The 90th percentile for microscopic extension was 12.0 mm (13.0, 9.7, and 4.4 mm for Grade 1 to 3, respectively). The CT lung windows correlated better with the pathologic size than did the mediastinal windows (gross pathologic size overestimated by a mean of 5.8 mm; composite size [gross plus microscopic extension] underestimated by a mean of 1.2 mm). For a GTV contoured on the CT lung windows, the margin required to cover microscopic extension for 90% of the cases would be 9 mm (9, 7, and 4 mm for Grade 1 to 3, respectively). The potential microscopic extension dosimetric coverage (55 Gy) varied substantially between the stereotactic radiotherapy schedules. Conclusion: For lung adenocarcinomas, the GTV should be contoured using CT lung windows. Although a GTV based on the CT lung windows would underestimate the gross tumor size plus microscopic extension by only 1.2 mm for the average case, the clinical target volume expansion required to cover the microscopic extension in 90% of cases could be as large as 9 mm, although considerably smaller for high-grade tumors

  8. MR coronary angiography with breath-hold targeted volumes : Preliminary clinical results

    NARCIS (Netherlands)

    van Geuns, R J; Wielopolski, P A; de Bruin, Hein G.; Rensing, B J; Hulshoff, Marc; van Ooijen, P M; de Feyter, P J; Oudkerk, M

    2000-01-01

    PURPOSE: To assess the clinical value of a magnetic resonance (MR) coronary angiography strategy involving a small targeted volume to image one coronary segment in a single breath hold for the detection of greater than 50% stenosis. MATERIALS AND METHODS: Thirty-eight patients referred for elective

  9. MR coronary angiography with breath-hold targeted volumes: preliminary clinical results

    NARCIS (Netherlands)

    R.J.M. van Geuns (Robert Jan); P.A. Wielopolski (Piotr); H.G. de Bruin (Hein); B.J.W.M. Rensing (Benno); M. Hulshoff (Maarten); P.M.A. van Ooijen (Peter); P.J. de Feyter (Pim); M. Oudkerk (Matthijs)

    2000-01-01

    textabstractPURPOSE: To assess the clinical value of a magnetic resonance (MR) coronary angiography strategy involving a small targeted volume to image one coronary segment in a single breath hold for the detection of greater than 50% stenosis. MATERIALS AND METHODS:

  10. Dosimetric Advantages of Midventilation Compared With Internal Target Volume for Radiation Therapy of Pancreatic Cancer

    NARCIS (Netherlands)

    Lens, Eelco; van der Horst, Astrid; Versteijne, Eva; van Tienhoven, Geertjan; Bel, Arjan

    2015-01-01

    The midventilation (midV) approach can be used to take respiratory-induced pancreatic tumor motion into account during radiation therapy. In this study, the dosimetric consequences for organs at risk and tumor coverage of using a midV approach compared with using an internal target volume (ITV) were

  11. Optimal target search on a fast-folding polymer chain with volume exchange

    DEFF Research Database (Denmark)

    Lomholt, Michael Andersen; Ambjörnsson, T.; Metzler, R.

    2005-01-01

    We study the search process of a target on a rapidly folding polymer ("DNA") by an ensemble of particles ("proteins"), whose search combines 1D diffusion along the chain, Lévy type diffusion mediated by chain looping, and volume exchange. A rich behavior of the search process is obtained...

  12. Investigations on the necessity of dose calculations for several planes of the target volume

    International Nuclear Information System (INIS)

    Richter, E.

    1987-01-01

    In radiotherapy planning, the shape of a target volume can at present be exactly delimited by means of computed tomography. A method often applied is to project the largest target volume scan on the plane of the central ray and to calculate the dose in this plane. This method does not allow to take into account any change of the target volume scan which will be mainly due to the body contours of the patient. The results of dose calculations made in several planes for pharyngeal and laryngeal tumors are presented. With this procedure, 33 out of 60 irradiation techniques for nine tumor sites meet the requirements with regard to the central ray plane. If several planes are regarded, this is only true for ten irradiation plans. If is therefore absolutely necessary to calculate the doses of several planes if the target volume has an irregular shape or if the body contours vary considerably. This is the only way to prevent a false treatment caused by possibly severe dose excesses or dose insufficiencies in radiotherapy. (orig.) [de

  13. Delineation of target volumes and organs at risk in adjuvant radiotherapy of early breast cancer

    DEFF Research Database (Denmark)

    Holck Nielsen, Mette; Berg, Martin; Pedersen, Anders N

    2013-01-01

    During the past decade planning of adjuvant radiotherapy (RT) of early breast cancer has changed from two-dimensional (2D) to 3D conformal techniques. In the planning computerised tomography (CT) scan both the targets for RT and the organs at risk (OARs) are visualised, enabling an increased focus...... on target dose coverage and homogeneity with only minimal dose to the OARs. To ensure uniform RT in the national prospective trials of the Danish Breast Cancer Cooperative Group (DBCG), a national consensus for the delineation of clinical target volumes (CTVs) and OARs was required....

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  15. The target volume concept at the recording of external beam radiotherapy

    International Nuclear Information System (INIS)

    Quast, U.; Glaeser, L.

    1981-01-01

    With the aim of complete, exact and reproducible manual recording and documentation of external beam radiotherapy a concept is proposed providing treatment planning and recording related to space and time for target volumes of different order corresponding to Ist, IInd or IIIrd part of treatment course, regarding all dose limiting organs at risk. The record consists of the dosage plan for medical treatment planning, the treatment plan for physical dose distribution planning and the treatment record of absorbed doses delivered as well as a checklist for patient and machine set-up, and labels for intended actions during treatment development. A clear arrangement of the record form in logical order was found, demanding exact specification of target(s) and beam(s) and their relation in space and time; asking for verbal and graphical description of target volumes, organs at risk, patient positioning, beam portals and dose reference points in terms of patients' anatomy; emphasizing the most important medical data by marked areas and leaving enough empty space for additional data, remarks or comments. During several years of clinical use these record forms proved to be suitable for all cases of external beam therapy, for complex situations of target volumes and treatment-scheduling, for all treatment techniques and radiation qualities and for all ways of physical treatment planning. They can be extended to automatic treatment verification, monitoring and recording as well as to the application of in-vivo-measurements of absorbed doses. (orig.) [de

  16. Improvement of particle-based volume rendering for visualizing irregular volume data sets

    OpenAIRE

    Sakamoto, Naohisa; Kawamura, Takuma; Koyamada, Koji; Nozaki, Kazunori

    2010-01-01

    We present a technique for previewing large-scale irregular volume datasets using an improved particle-based volume rendering (PBVR) technique. Volume rendering of irregular grid volume data is considerably more complicated than that of regular grid data, since the sampling and compositing processes, which must be done in visibility order, are not straightforward. In our original PBVR, rendering involves generating and projecting sub-pixel-size, opaque, and emissive particles without visibili...

  17. Volume of Home and Community Based Services and...

    Data.gov (United States)

    U.S. Department of Health & Human Services — Volume of Home- and Community-Based Services and Time to Nursing-Home Placement The purpose of this study was to determine whether the volume of Home and Community...

  18. The ADVANCE project: Formal evaluation of the targeted deployment. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    The Advanced Driver and Vehicle Advisory Navigation ConcEpt (ADVANCE) was an invehicle advanced traveler information system (ATIS) that operated in the northwest suburbs of Chicago, Illinois. It was designed to provide origin-destination shortest-time route guidance to a vehicle based on (a) an on-board static (fixed) data base of average network link travel times by time of day, combined as available and appropriate with (b) dynamic (real-time) information on traffic conditions provided by radio frequency (RF) communications to and from a traffic information center (TIC). Originally conceived in 1990 as a major project that would have installed 3,000 to 5,000 route guidance units in privately owned vehicles throughout the test area, ADVANCE was restructured in 1995 as a {open_quotes}targeted deployment,{close_quotes} in which approximately 80 vehicles were to be equipped with the guidance units - Mobile Navigation Assistants (MNAs) - to be in full communication with the TIC while driving the ADVANCE test area road system. Volume one consists of the evaluation managers overview report, and several appendices containing test results.

  19. Microinvasion of liver metastases from colorectal cancer: predictive factors and application for determining clinical target volume

    International Nuclear Information System (INIS)

    Qian, Yang; Zeng, Zhao-Chong; Ji, Yuan; Xiao, Yin-Ping

    2015-01-01

    This study evaluates the microscopic characteristics of liver metastases from colorectal cancer (LMCRC) invasion and provides a reference for expansion from gross tumor volume (GTV) to clinical targeting volume (CTV). Data from 129 LMCRC patients treated by surgical resection at our hospital between January 2008 and September 2009 were collected for study. Tissue sections used for pathology and clinical data were reviewed. Patient information used for the study included gender, age, original tumor site, number of tumors, tumor size, levels of carcinoembryonic antigen (CEA) and carbohydrate antigen 199 (CA199), synchronous or metachronous liver metastases, and whether patients received chemotherapy. The distance of liver microinvasion from the tumor boundary was measured microscopically by two senior pathologists. Of 129 patients evaluated, 81 (62.8 %) presented microinvasion distances from the tumor boundary ranging between 1.0 − 7.0 mm. A GTV-to-CTV expansion of 5, 6.7, or 7.0 mm was required to provide a 95, 99, or 100 % probability, respectively, of obtaining clear resection margins by microscopic observation. The extent of invasion was not related to gender, age, synchronous or metachronous liver metastases, tumor size, CA199 level, or chemotherapy. The extent of invasion was related to original tumor site, CEA level, and number of tumors. A scoring system was established based on the latter three positive predictors. Using this system, an invasion distance less than 3 mm was measured in 93.4 % of patients with a score of ≤1 point, but in only 85.7 % of patients with a score of ≤2 points. The extent of tumor invasion in our LMCRC patient cohort correlated with original tumor site, CEA level, and number of tumors. These positive predictors may potentially be used as a scoring system for determining GTV-to-CTV expansion

  20. Anatomic Boundaries of the Clinical Target Volume (Prostate Bed) After Radical Prostatectomy

    International Nuclear Information System (INIS)

    Wiltshire, Kirsty L.; Brock, Kristy K.; Haider, Masoom A.; Zwahlen, Daniel; Kong, Vickie; Chan, Elisa; Moseley, Joanne; Bayley, Andrew; Catton, Charles; Chung, Peter W.M.; Gospodarowicz, Mary; Milosevic, Michael; Kneebone, Andrew; Warde, Padraig; Menard, Cynthia

    2007-01-01

    Purpose: We sought to derive and validate an interdisciplinary consensus definition for the anatomic boundaries of the postoperative clinical target volume (CTV, prostate bed). Methods and Materials: Thirty one patients who had planned for radiotherapy after radical prostatectomy were enrolled and underwent computed tomography and magnetic resonance imaging (MRI) simulation prior to radiotherapy. Through an iterative process of consultation and discussion, an interdisciplinary consensus definition was derived based on a review of published data, patterns of local failure, surgical practice, and radiologic anatomy. In validation, we analyzed the distribution of surgical clips in reference to the consensus CTV and measured spatial uncertainties in delineating the CTV and vesicourethral anastomosis. Clinical radiotherapy plans were retrospectively evaluated against the consensus CTV (prostate bed). Results: Anatomic boundaries of the consensus CTV (prostate bed) are described. Surgical clips (n = 339) were well distributed throughout the CTV. The vesicourethral anastomosis was accurately localized using central sagittal computed tomography reconstruction, with a mean ± standard deviation uncertainty of 1.8 ± 2.5 mm. Delineation uncertainties were small for both MRI and computed tomography (mean reproducibility, 0-3.8 mm; standard deviation, 1.0-2.3); they were most pronounced in the anteroposterior and superoinferior dimensions and at the superior/posterior-most aspect of the CTV. Retrospectively, the mean ± standard deviation CTV (prostate bed) percentage of volume receiving 100% of prescribed dose was only 77% ± 26%. Conclusions: We propose anatomic boundaries for the CTV (prostate bed) and present evidence supporting its validity. In the absence of gross recurrence, the role of MRI in delineating the CTV remains to be confirmed. The CTV is larger than historically practiced at our institution and should be encompassed by a microscopic tumoricidal dose

  1. MRI and CT imaging for preoperative target volume delineation in breast-conserving therapy.

    Science.gov (United States)

    den Hartogh, Mariska D; Philippens, Marielle E P; van Dam, Iris E; Kleynen, Catharina E; Tersteeg, Robbert J H A; Pijnappel, Ruud M; Kotte, Alexis N T J; Verkooijen, Helena M; van den Bosch, Maurice A A J; van Vulpen, Marco; van Asselen, Bram; van den Bongard, Hjg Desirée

    2014-02-26

    Accurate tumor bed delineation after breast-conserving surgery is important. However, consistency among observers on standard postoperative radiotherapy planning CT is low and volumes can be large due to seroma formation. A preoperative delineation of the tumor might be more consistent. Therefore, the purpose of this study was to determine the consistency of preoperative target volume delineation on CT and MRI for breast-conserving radiotherapy. Tumors were delineated on preoperative contrast-enhanced (CE) CT and newly developed 3D CE-MR images, by four breast radiation oncologists. Clinical target volumes (CTVs) were created by addition of a 1.5 cm margin around the tumor, excluding skin and chest wall. Consistency in target volume delineation was expressed by the interobserver variability. Therefore, the conformity index (CI), center of mass distance (dCOM) and volumes were calculated. Tumor characteristics on CT and MRI were scored by an experienced breast radiologist. Preoperative tumor delineation resulted in a high interobserver agreement with a high median CI for the CTV, for both CT (0.80) and MRI (0.84). The tumor was missed on CT in 2/14 patients (14%). Leaving these 2 patients out of the analysis, CI was higher on MRI compared to CT for the GTV (p<0.001) while not for the CTV (CT (0.82) versus MRI (0.84), p=0.123). The dCOM did not differ between CT and MRI. The median CTV was 48 cm3 (range 28-137 cm3) on CT and 59 cm3 (range 30-153 cm3) on MRI (p<0.001). Tumor shapes and margins were rated as more irregular and spiculated on CE-MRI. This study showed that preoperative target volume delineation resulted in small target volumes with a high consistency among observers. MRI appeared to be necessary for tumor detection and the visualization of irregularities and spiculations. Regarding the tumor delineation itself, no clinically relevant differences in interobserver variability were observed. These results will be used to study the potential for future MRI

  2. Prostate bed target interfractional motion using RTOG consensus definitions and daily CT on rails. Does target motion differ between superior and inferior portions of the clinical target volume

    Energy Technology Data Exchange (ETDEWEB)

    Verma, Vivek; Zhou, Sumin; Enke, Charles A.; Wahl, Andrew O. [University of Nebraska Medical Center, Department of Radiation Oncology, Omaha (United States); Chen, Shifeng [University of Maryland School of Medicine, Department of Radiation Oncology, Baltimore, MD (United States)

    2017-01-15

    Using high-quality CT-on-rails imaging, the daily motion of the prostate bed clinical target volume (PB-CTV) based on consensus Radiation Therapy Oncology Group (RTOG) definitions (instead of surgical clips/fiducials) was studied. It was assessed whether PB motion in the superior portion of PB-CTV (SUP-CTV) differed from the inferior PB-CTV (INF-CTV). Eight pT2-3bN0-1M0 patients underwent postprostatectomy intensity-modulated radiotherapy, totaling 300 fractions. INF-CTV and SUP-CTV were defined as PB-CTV located inferior and superior to the superior border of the pubic symphysis, respectively. Daily pretreatment CT-on-rails images were compared to the planning CT in the left-right (LR), superoinferior (SI), and anteroposterior (AP) directions. Two parameters were defined: ''total PB-CTV motion'' represented total shifts from skin tattoos to RTOG-defined anatomic areas; ''PB-CTV target motion'' (performed for both SUP-CTV and INF-CTV) represented shifts from bone to RTOG-defined anatomic areas (i. e., subtracting shifts from skin tattoos to bone). Mean (± standard deviation, SD) total PB-CTV motion was -1.5 (± 6.0), 1.3 (± 4.5), and 3.7 (± 5.7) mm in LR, SI, and AP directions, respectively. Mean (± SD) PB-CTV target motion was 0.2 (±1.4), 0.3 (±2.4), and 0 (±3.1) mm in the LR, SI, and AP directions, respectively. Mean (± SD) INF-CTV target motion was 0.1 (± 2.8), 0.5 (± 2.2), and 0.2 (± 2.5) mm, and SUP-CTV target motion was 0.3 (± 1.8), 0.5 (± 2.3), and 0 (± 5.0) mm in LR, SI, and AP directions, respectively. No statistically significant differences between INF-CTV and SUP-CTV motion were present in any direction. There are no statistically apparent motion differences between SUP-CTV and INF-CTV. Current uniform planning target volume (PTV) margins are adequate to cover both portions of the CTV. (orig.) [German] Zur Evaluation der interfraktionellen Variabilitaet des klinischen Zielvolumens der Prostataloge

  3. Target volume and position variations during intensity-modulated radiotherapy for patients with nasopharyngeal carcinoma

    Directory of Open Access Journals (Sweden)

    Tan W

    2013-11-01

    Full Text Available Wenyong Tan,* Yanping Li,* Guang Han, Jiaozhen Xu, Xiaohong Wang, Ying Li, Desheng HuDepartment of Radiation Oncology, Hubei Cancer Hospital, Wuhan, People's Republic of China*These authors contributed equally to this workPurpose: Considerable anatomical changes occur during intensity-modulated radiotherapy (IMRT for nasopharyngeal carcinoma (NPC. This study aimed to quantify volumetric and positional variations of the target volume during IMRT.Materials and methods: Twenty patients with locally advanced NPC who received concurrent (13 patients or sequential (seven patients chemoradiotherapy were prospectively recruited and underwent planning computed tomography (CT and six repeat CTs (every five fractions. Each repeat CT was rigidly registered to the planning CT. Gross tumor volume (GTV and elective clinical target volume (CTV were manually delineated on each axial CT image. CTVs of the primary tumor and lymph nodes were expanded with 5 mm margins to corresponding GTVs, with necessary modifications. Volume loss, system and random errors, and the mean and three-dimensional vector displacements were calculated and compared statistically.Results: Volumes of the primary tumor and small (>1 cm, ≤3 cm and large (>3 cm positive neck lymph nodes decreased at a rate of 2.6%, 3.7%, and 3.9% per treatment day, respectively. CTVs of the primary tumor, lymph nodes, and elective region decreased 1.5%, 2.3%, and 0.3% per treatment day, respectively. Average displacements of the GTVs and CTVs were <1.3 mm in all directions. GTVs and CTVs of the large and small lymph nodes shifted medially by 0.8–1.3 and 0.6–1.2 mm, respectively, on average. Average three-dimensional displacements of the GTVs and CTVs were 3.4–4.3 mm and 2.5–3.7 mm, respectively. Volume loss and displacements in most directions were significantly larger in patients receiving concurrent chemoradiotherapy than in those receiving sequential therapy. Volume loss and displacements of the

  4. Proton therapy of iris melanoma with 50 CGE : Influence of target volume on clinical outcome.

    Science.gov (United States)

    Riechardt, Aline I; Karle, Bettina; Cordini, Dino; Heufelder, Jens; Budach, Volker; Joussen, Antonia M; Gollrad, Johannes

    2017-11-01

    The aim of this study was to evaluate local tumour control, incidence of radiation-induced glaucoma and associated interventions of sector-based and whole anterior segment proton beam therapy (PBT) for the treatment of iris melanoma. We retrospectively analysed the data of 77 patients with iris melanoma who underwent PBT applied as 50 CGE in four daily fractions. Of the patients, 47 received PBT with a circular-shaped collimator and 30 with a conformal sector-shaped target volume. Local control, eye preservation and secondary glaucoma were evaluated. Median follow-up time was 54.9 months. Local tumour control was 100% in patients receiving whole anterior segment irradiation. Two patients developed pigment dispersion in the non-irradiated area after sector-based PBT and received whole anterior segment salvage PBT. The mean volume of ciliary body irradiated was 89.0% and 34.9% for whole anterior segment and lesion-based irradiation, respectively. At the end of follow-up, secondary glaucoma was found in 74.3% of the patients with whole anterior segment irradiation and in 19.2% with sector-based irradiation. Patients with sector-based PBT had a stable visual acuity of logMAR 0.1, while it declined from logMAR 0.1 to 0.4 after whole anterior segment irradiation. We found a significant reduction in radiation-induced secondary glaucoma and glaucoma-associated surgical interventions and stable visual acuity after sector-based irradiation compared with whole anterior segment irradiation. Sector-based irradiation revealed a higher risk for local recurrence, but selected patients with well-circumscribed iris melanoma benefit from applying a lesion-based target volume when treated with sector-based PBT.

  5. Target volume delineation in external beam partial breast irradiation: less inter-observer variation with preoperative- compared to postoperative delineation

    NARCIS (Netherlands)

    Leij, F. van der; Elkhuizen, P.H.M.; Janssen, T.M.; Poortmans, P.M.P.; Sangen, M. van der; Scholten, A.N.; Vliet-Vroegindeweij, C. van; Boersma, L.J.

    2014-01-01

    The challenge of adequate target volume definition in external beam partial breast irradiation (PBI) could be overcome with preoperative irradiation, due to less inter-observer variation. We compared the target volume delineation for external beam PBI on preoperative versus postoperative CT scans of

  6. A two isocenter IMRT technique with a controlled junction dose for long volume targets

    International Nuclear Information System (INIS)

    Zeng, G G; Heaton, R K; Catton, C N; Chung, P W; O'Sullivan, B; Lau, M; Parent, A; Jaffray, D A

    2007-01-01

    Most IMRT techniques have been designed to treat targets smaller than the field size of conventional linac accelerators. In order to overcome the field size restrictions in applying IMRT, we developed a two isocenter IMRT technique to treat long volume targets. The technique exploits an extended dose gradient throughout a junction region of 4-6 cm to minimize the impact of field match errors on a junction dose and manipulates the inverse planning and IMRT segments to fill in the dose gradient and achieve dose uniformity. Techniques for abutting both conventional fields with IMRT ('Static + IMRT') and IMRT fields ('IMRT + IMRT') using two separate isocenters have been developed. Five long volume sarcoma cases have been planned in Pinnacle (Philips, Madison, USA) using Elekta Synergy and Varian 2100EX linacs; two of the cases were clinically treated with this technique. Advantages were demonstrated with well-controlled junction target uniformity and tolerance to setup uncertainties. The junction target dose heterogeneity was controlled at a level of ±5%; for 3 mm setup errors at the field edges, the junction target dose changed less than 5% and the dose sparing to organs at risk (OARs) was maintained. Film measurements confirmed the treatment planning results

  7. Planning target volume (PTV) definition and its effects in the radiotherapy; Definicao do volume de planejamento do alvo (PTV) e seu efeito na radioterapia

    Energy Technology Data Exchange (ETDEWEB)

    Poli, Maria Esmeralda Ramos

    2007-07-01

    Tills work intends to study the margins required to define a planning target volume (PTV) for adequate treatment of the mobile tumors such as prostate or those located in areas with less mobility as the ones in head and neck region, in the absence of daily localization imaging based. It is also intends to evaluate the impact caused by the PTV, in terms of dose, to the critical structures surrounding the PTV and its influence when inverse planning is used in the intensity-modulated radiation therapy (IMRT). Data from 387 prostate patients were analyzed retrospectively. Every patient in the study received daily pre-treatment localization with 2D ultrasound resulting in a total of 10,327 localizations, each comprising of an isocenter displacement in 3 directions: anterior-posterior (AP), right-left lateral (RL), and superior-inferior (SI). The mean displacement and standard deviation (SD) for each direction for each patient was computed from daily treatment records. The uncertainties (SD) in the target position were 4.4 mm (AP), 3.6 mm (RL), and 4.5 mm (SI). A study of the uncertainties in the daily positioning of 78 head and neck patients who used thermoplastic mask to immobilize them, evaluated with electronic portal imaging device (EPID), showed variations (SD) in the isocenter treatment position of 3.1 mm (AP), 1.5 mm (RL), and 4.5 mm (SI). By applying these shifts in an anthropomorphic phantom it was studied the dose-volume histograms resultant of the isocenter displacement in the daily treatment. The result showed the importance of putting margins in the clinical target volume to assure an adequate treatment and also showed that isocenter daily variation can cause an increase to the dose greater than the tolerance level to the critical organs. (author)

  8. SU-E-T-578: On Definition of Minimum and Maximum Dose for Target Volume

    Energy Technology Data Exchange (ETDEWEB)

    Gong, Y; Yu, J; Xiao, Y [Thomas Jefferson University Hospital, Philadelphia, PA (United States)

    2015-06-15

    Purpose: This study aims to investigate the impact of different minimum and maximum dose definitions in radiotherapy treatment plan quality evaluation criteria by using tumor control probability (TCP) models. Methods: Dosimetric criteria used in RTOG 1308 protocol are used in the investigation. RTOG 1308 is a phase III randomized trial comparing overall survival after photon versus proton chemoradiotherapy for inoperable stage II-IIIB NSCLC. The prescription dose for planning target volume (PTV) is 70Gy. Maximum dose (Dmax) should not exceed 84Gy and minimum dose (Dmin) should not go below 59.5Gy in order for the plan to be “per protocol” (satisfactory).A mathematical model that simulates the characteristics of PTV dose volume histogram (DVH) curve with normalized volume is built. The Dmax and Dmin are noted as percentage volumes Dη% and D(100-δ)%, with η and d ranging from 0 to 3.5. The model includes three straight line sections and goes through four points: D95%= 70Gy, Dη%= 84Gy, D(100-δ)%= 59.5 Gy, and D100%= 0Gy. For each set of η and δ, the TCP value is calculated using the inhomogeneously irradiated tumor logistic model with D50= 74.5Gy and γ50=3.52. Results: TCP varies within 0.9% with η; and δ values between 0 and 1. With η and η varies between 0 and 2, TCP change was up to 2.4%. With η and δ variations from 0 to 3.5, maximum of 8.3% TCP difference is seen. Conclusion: When defined maximum and minimum volume varied more than 2%, significant TCP variations were seen. It is recommended less than 2% volume used in definition of Dmax or Dmin for target dosimetric evaluation criteria. This project was supported by NIH grants U10CA180868, U10CA180822, U24CA180803, U24CA12014 and PA CURE Grant.

  9. Proposed Volume Standards for 2018, and the Biomass-Based Diesel Volume for 2019

    Science.gov (United States)

    EPA proposed volume requirements under the Renewable Fuel Standard (RFS) program for 2018 for cellulosic biofuel, biomass-based diesel, advanced biofuel, and total renewable fuel, and biomass-based diesel for 2019 under the RFS.

  10. Folate-targeted docetaxel-lipid-based-nanosuspensions for active-targeted cancer therapy.

    Science.gov (United States)

    Wang, Lili; Li, Min; Zhang, Na

    2012-01-01

    The purpose of this study was to develop two novel drug delivery systems based on biodegradable docetaxel-lipid-based-nanosuspensions. The first one was poly(ethylene glycol)- modified docetaxel-lipid-based-nanosuspensions (pLNS). It was developed to increase the cycle time of the drug within the body and enhance the accumulation of the drug at the tumor site. The second one was targeted docetaxel-lipid-based-nanosuspensions (tLNS) using folate as the target ligand. The tLNS could target the tumor cells that overexpressed folate receptor (FR). The morphology, particle size, and zeta potential of pLNS and tLNS were characterized, respectively. The in vitro cytotoxicity evaluation of Duopafei(®), pLNS, and tLNS were performed in human hepatocellular liver carcinoma HepG2 (FR-) and B16 (FR+) cells, respectively. The in vivo antitumor efficacy and pharmacokinetics, as well as the drug tissue distribution, were evaluated in Kunming mice bearing B16 cells. The particle size of pLNS was 204.2 ± 6.18 nm and tLNS had a mean particle size of 220.6 ± 9.54 nm. Cytotoxicity of tLNS against B16 (FR+) cell lines was superior to pLNS (P < 0.05), while there was no significant difference in the half maximum inhibitory concentration values for HepG2 (FR-) cells between pLNS and tLNS. The results of the in vivo antitumor efficacy evaluation showed that tLNS exhibited higher antitumor efficacy by reducing tumor volume (P < 0.01) compared with Duopafei and pLNS, respectively. The results of the in vivo biodistribution study indicate that the better antitumor efficacy of tLNS was attributed to the increased accumulation of the drug in the tumor.

  11. Gold markers for tumor localization and target volume delineation in radiotherapy for rectal cancer

    International Nuclear Information System (INIS)

    Vorwerk, Hilke; Christiansen, Hans; Hess, Clemens Friedrich; Hermann, Robert Michael; Liersch, Thorsten; Ghadimi, Michael; Rothe, Hilka

    2009-01-01

    In locally advanced rectal cancer, neoadjuvant radiochemotherapy is indicated. To improve target volume definition for radiotherapy planning, the potential of implanted gold markers in the tumor region was evaluated. In nine consecutive patients, two to three gold markers were implanted in the tumor region during rigid rectoscopy. Computed tomography scans were performed during treatment planning. All electronic portal imaging devices (EPIDs) recorded during treatment series were analyzed. All patients underwent complete tumor resection with meticulous histopathologic examination. The gold markers could easily be implanted into the mesorectal tissue at the caudal tumor border without any complications. They were helpful in identifying the inferior border of the planning target volume in order to spare normal tissue (in particular anal structures). No significant shift of the markers was found during the course of therapy. Marker matching of the EPIDs did not improve patient positioning in comparison to bone structure matching. The former position of at least one marker could be identified in all patients during histopathologic examination. The use of gold marker enables a more precise definition of the target volume for radiotherapy in patients with rectal cancer. This could eventually allow a better protection of anal structures of patients with a tumor localization = 5 cm cranial of the anal sphincter. The implantation of the gold markers improved communication between the surgeon, the radiooncologist and the pathologist resulting in intensified exchange of relevant informations. (orig.)

  12. Consequences of additional use of PET information for target volume delineation and radiotherapy dose distribution for esophageal cancer

    International Nuclear Information System (INIS)

    Muijs, Christina T.; Schreurs, Liesbeth M.; Busz, Dianne M.; Beukema, Jannet C.; Borden, Arnout J. van der; Pruim, Jan; Van der Jagt, Eric J.; Plukker, John Th.; Langendijk, Johannes A.

    2009-01-01

    Background and purpose: To determine the consequences of target volume (TV) modifications, based on the additional use of PET information, on radiation planning, assuming PET/CT-imaging represents the true extent of the tumour. Materials and methods: For 21 patients with esophageal cancer, two separate TV's were retrospectively defined based on CT (CT-TV) and co-registered PET/CT images (PET/CT-TV). Two 3D-CRT plans (prescribed dose 50.4 Gy) were constructed to cover the corresponding TV's. Subsequently, these plans were compared for target coverage, normal tissue dose-volume histograms and the corresponding normal tissue complication probability (NTCP) values. Results: The addition of PET led to the modification of CT-TV with at least 10% in 12 of 21 patients (57%) (reduction in 9, enlargement in 3). PET/CT-TV was inadequately covered by the CT-based treatment plan in 8 patients (36%). Treatment plan modifications resulted in significant changes (p < 0.05) in dose distributions to heart and lungs. Corresponding changes in NTCP values ranged from -3% to +2% for radiation pneumonitis and from -0.2% to +1.2% for cardiac mortality. Conclusions: This study demonstrated that TV's based on CT might exclude PET-avid disease. Consequences are under dosing and thereby possibly ineffective treatment. Moreover, the addition of PET in radiation planning might result in clinical important changes in NTCP.

  13. Pronuclear Injection-Based Targeted Transgenesis.

    Science.gov (United States)

    Schilit, Samantha L P; Ohtsuka, Masato; Quadros, Rolen M; Gurumurthy, Channabasavaiah B

    2016-10-11

    Microinjection of DNA expression cassettes into fertilized zygotes has been a standard method for generating transgenic animal models. While efficient, the injected DNA integrates randomly into the genome, leading to potential disruption of endogenous genes or regulatory elements, variation in copy number, or integration into heterochromatic regions that inhibit transgene expression. A recently developed method addresses such pitfalls of traditional transgenesis by targeting the transgene to predetermined sites in the genome that can safely harbor exogenous DNA. This method, called Pronuclear Injection-based Targeted Transgenesis (PITT), employs an enzymatic transfer of exogenous DNA from a donor vector to a previously created landing-pad site in the mouse genome. DNA transfer is achieved using molecular tools such as the Cre-LoxP recombinase and PhiC31-attB/P integrase systems. Here, we provide protocols for performing PITT and an overview of the current PITT tools available to the research community. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  14. Control volume based hydrocephalus research; analysis of human data

    Science.gov (United States)

    Cohen, Benjamin; Wei, Timothy; Voorhees, Abram; Madsen, Joseph; Anor, Tomer

    2010-11-01

    Hydrocephalus is a neuropathophysiological disorder primarily diagnosed by increased cerebrospinal fluid volume and pressure within the brain. To date, utilization of clinical measurements have been limited to understanding of the relative amplitude and timing of flow, volume and pressure waveforms; qualitative approaches without a clear framework for meaningful quantitative comparison. Pressure volume models and electric circuit analogs enforce volume conservation principles in terms of pressure. Control volume analysis, through the integral mass and momentum conservation equations, ensures that pressure and volume are accounted for using first principles fluid physics. This approach is able to directly incorporate the diverse measurements obtained by clinicians into a simple, direct and robust mechanics based framework. Clinical data obtained for analysis are discussed along with data processing techniques used to extract terms in the conservation equation. Control volume analysis provides a non-invasive, physics-based approach to extracting pressure information from magnetic resonance velocity data that cannot be measured directly by pressure instrumentation.

  15. Home mechanical ventilation for COPD: high-intensity versus target volume noninvasive ventilation.

    Science.gov (United States)

    Storre, Jan H; Matrosovich, Elena; Ekkernkamp, Emelie; Walker, David J; Schmoor, Claudia; Dreher, Michael; Windisch, Wolfram

    2014-09-01

    High-intensity noninvasive ventilation (HI-NIV) is the most effective means of improving several physiological and clinical parameters in subjects with chronic hypercapnic COPD. Whether the newer hybrid mode using target tidal volume noninvasive ventilation (target V(T) NIV) provides additional benefits remains unclear. Subjects with COPD successfully established on long-term HI-NIV were switched to target V(T) NIV. Optimal target V(T) settings according to nocturnal transcutaneous P(CO2) measurements were achieved following a randomized crossover trial using 8 mL/kg ideal body weight and 110% of individual V(T) during HI-NIV, respectively. The following parameters were compared at the beginning of the trial while subjects were on HI-NIV, and after 3 months on optimal target V(T) NIV: sleep quality by polysomnography, overnight gas exchange, subjects' tolerance, overnight pneumotachygraphic measurements during NIV, health-related quality of life (severe respiratory insufficiency questionnaire), exercise capacity (6-min walk test), and lung function. Ten of 14 subjects completed the study. There were no differences between HI-NIV and target V(T) NIV in any of the above-mentioned parameters. Specifically, the mean overnight transcutaneous P(CO2) was equivalent under each form of ventilation (both 45 ± 5 mm Hg, P = .75). Switching subjects from well-established HI-NIV to target V(T) NIV shows no clinical benefits in chronic hypercapnic COPD. In particular, sleep quality, the control of nocturnal hypoventilation, daytime hypercapnia, overnight ventilation patterns, subjects' tolerance, health-related quality of life, lung function, and exercise capability were all similar in subjects who underwent HI-NIV and target V(T) NIV. Nevertheless, target V(T) NIV might offer some physiological advantages in breathing pattern and might be beneficial in some individual patients. (German Clinical Trials Register [www.drks.de] Registration DRKS00000450.). Copyright © 2014 by

  16. Definition and delineation of the clinical target volume for rectal cancer

    International Nuclear Information System (INIS)

    Roels, Sarah; Duthoy, Wim; Haustermans, Karin; Penninckx, Freddy; Vandecaveye, Vincent; Boterberg, Tom; Neve, Wilfried de

    2006-01-01

    Purpose: Optimization of radiation techniques to maximize local tumor control and to minimize small bowel toxicity in locally advanced rectal cancer requires proper definition and delineation guidelines for the clinical target volume (CTV). The purpose of this investigation was to analyze reported data on the predominant locations and frequency of local recurrences and lymph node involvement in rectal cancer, to propose a definition of the CTV for rectal cancer and guidelines for its delineation. Methods and Materials: Seven reports were analyzed to assess the incidence and predominant location of local recurrences in rectal cancer. The distribution of lymphatic spread was analyzed in another 10 reports to record the relative frequency and location of metastatic lymph nodes in rectal cancer, according to the stage and level of the primary tumor. Results: The mesorectal, posterior, and inferior pelvic subsites are most at risk for local recurrences, whereas lymphatic tumor spread occurs mainly in three directions: upward into the inferior mesenteric nodes; lateral into the internal iliac lymph nodes; and, in a few cases, downward into the external iliac and inguinal lymph nodes. The risk for recurrence or lymph node involvement is related to the stage and the level of the primary lesion. Conclusion: Based on a review of articles reporting on the incidence and predominant location of local recurrences and the distribution of lymphatic spread in rectal cancer, we defined guidelines for CTV delineation including the pelvic subsites and lymph node groups at risk for microscopic involvement. We propose to include the primary tumor, the mesorectal subsite, and the posterior pelvic subsite in the CTV in all patients. Moreover, the lateral lymph nodes are at high risk for microscopic involvement and should also be added in the CTV

  17. Variation of clinical target volume definition in three-dimensional conformal radiation therapy for prostate cancer

    International Nuclear Information System (INIS)

    Valicenti, Richard K.; Sweet, John W.; Hauck, Walter W.; Hudes, Richard S.; Lee, Tony; Dicker, Adam P.; Waterman, Frank M.; Anne, Pramila R.; Corn, Benjamin W.; Galvin, James M.

    1999-01-01

    Purpose: Currently, three-dimensional conformal radiation therapy (3D-CRT) planning relies on the interpretation of computed tomography (CT) axial images for defining the clinical target volume (CTV). This study investigates the variation among multiple observers to define the CTV used in 3D-CRT for prostate cancer. Methods and Materials: Seven observers independently delineated the CTVs (prostate ± seminal vesicles [SV]) from the CT simulation data of 10 prostate cancer patients undergoing 3D-CRT. Six patients underwent CT simulation without the use of contrast material and serve as a control group. The other 4 had urethral and bladder opacification with contrast medium. To determine interobserver variation, we evaluated the derived volume, the maximum dimensions, and the isocenter for each examination of CTV. We assessed the reliability in the CTVs among the observers by correlating the variation for each class of measurements. This was estimated by intraclass correlation coefficient (ICC), with 1.00 defining absolute correlation. Results: For the prostate volumes, the ICC was 0.80 (95% confidence interval [CI]: 0.56-0.96). This changed to 0.92 (95% CI: 0.75-0.99) with the use of contrast material. Similarly, the maximal prostatic dimensions were reliable and improved. There was poor agreement in defining the SV. For this structure, the ICC never exceeded 0.28. The reliability of the isocenter was excellent, with the ICC exceeding 0.83 and 0.90 for the prostate ± SV, respectively. Conclusions: In 3D-CRT for prostate cancer, there was excellent agreement among multiple observers to define the prostate target volume but poor agreement to define the SV. The use of urethral and bladder contrast improved the reliability of localizing the prostate. For all CTVs, the isocenter was very reliable and should be used to compare the variation in 3D dosimetry among multiple observers

  18. Retroperitoneal Sarcoma Target Volume and Organ at Risk Contour Delineation Agreement Among NRG Sarcoma Radiation Oncologists

    Energy Technology Data Exchange (ETDEWEB)

    Baldini, Elizabeth H., E-mail: ebaldini@partners.org [Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham and Women' s Hospital, Boston, Massachusetts (United States); Abrams, Ross A. [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States); Bosch, Walter [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Roberge, David [Department of Radiation Oncology, Centre Hospitalier de l' Universite de Montreal, Montreal, Quebec (Canada); Haas, Rick L.M. [Department of Radiotherapy, Netherlands Cancer Institute, 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); Olsen, Jeffrey R. [Department of Radiation Oncology, Washington University, St. Louis, Missouri (United States); Deville, Curtiland [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Chen, Yen-Lin [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Finkelstein, Steven E. [Translational Research Consortium, 21st Century Oncology, Scottsdale, Arizona (United States); DeLaney, Thomas F. [Department of Radiation Oncology, Massachusetts General Hospital, Boston, Massachusetts (United States); Wang, Dian [Department of Radiation Oncology, Rush University Medical Center, Chicago, Illinois (United States)

    2015-08-01

    Purpose: The purpose of this study was to evaluate the variability in target volume and organ at risk (OAR) contour delineation for retroperitoneal sarcoma (RPS) among 12 sarcoma radiation oncologists. Methods and Materials: Radiation planning computed tomography (CT) scans for 2 cases of RPS were distributed among 12 sarcoma radiation oncologists with instructions for contouring gross tumor volume (GTV), clinical target volume (CTV), high-risk CTV (HR CTV: area judged to be at high risk of resulting in positive margins after resection), and OARs: bowel bag, small bowel, colon, stomach, and duodenum. Analysis of contour agreement was performed using the simultaneous truth and performance level estimation (STAPLE) algorithm and kappa statistics. Results: Ten radiation oncologists contoured both RPS cases, 1 contoured only RPS1, and 1 contoured only RPS2 such that each case was contoured by 11 radiation oncologists. The first case (RPS 1) was a patient with a de-differentiated (DD) liposarcoma (LPS) with a predominant well-differentiated (WD) component, and the second case (RPS 2) was a patient with DD LPS made up almost entirely of a DD component. Contouring agreement for GTV and CTV contours was high. However, the agreement for HR CTVs was only moderate. For OARs, agreement for stomach, bowel bag, small bowel, and colon was high, but agreement for duodenum (distorted by tumor in one of these cases) was fair to moderate. Conclusions: For preoperative treatment of RPS, sarcoma radiation oncologists contoured GTV, CTV, and most OARs with a high level of agreement. HR CTV contours were more variable. Further clarification of this volume with the help of sarcoma surgical oncologists is necessary to reach consensus. More attention to delineation of the duodenum is also needed.

  19. Potential implications of the bystander effect on TCP and EUD when considering target volume dose heterogeneity.

    Science.gov (United States)

    Balderson, Michael J; Kirkby, Charles

    2015-01-01

    In light of in vitro evidence suggesting that radiation-induced bystander effects may enhance non-local cell killing, there is potential for impact on radiotherapy treatment planning paradigms such as the goal of delivering a uniform dose throughout the clinical target volume (CTV). This work applies a bystander effect model to calculate equivalent uniform dose (EUD) and tumor control probability (TCP) for external beam prostate treatment and compares the results with a more common model where local response is dictated exclusively by local absorbed dose. The broad assumptions applied in the bystander effect model are intended to place an upper limit on the extent of the results in a clinical context. EUD and TCP of a prostate cancer target volume under conditions of increasing dose heterogeneity were calculated using two models: One incorporating bystander effects derived from previously published in vitro bystander data ( McMahon et al. 2012 , 2013a); and one using a common linear-quadratic (LQ) response that relies exclusively on local absorbed dose. Dose through the CTV was modelled as a normal distribution, where the degree of heterogeneity was then dictated by changing the standard deviation (SD). Also, a representative clinical dose distribution was examined as cold (low dose) sub-volumes were systematically introduced. The bystander model suggests a moderate degree of dose heterogeneity throughout a target volume will yield as good or better outcome compared to a uniform dose in terms of EUD and TCP. For a typical intermediate risk prostate prescription of 78 Gy over 39 fractions maxima in EUD and TCP as a function of increasing SD occurred at SD ∼ 5 Gy. The plots only dropped below the uniform dose values for SD ∼ 10 Gy, almost 13% of the prescribed dose. Small, but potentially significant differences in the outcome metrics between the models were identified in the clinically-derived dose distribution as cold sub-volumes were introduced. In terms of

  20. Study of the relationship between the target tissue necrosis volume and the target tissue size in liver tumours using two-compartment finite element RFA modelling.

    Science.gov (United States)

    Zhang, Bing; Moser, Michael A J; Zhang, Edwin M; Luo, Yigang; Zhang, Hongbo; Zhang, Wenjun

    2014-12-01

    The aim of this study was to investigate the relationship between the target tissue necrosis volume and the target tissue size during the radiofrequency ablation (RFA) procedure. The target tissues with four different sizes (dxy = 20, 25, 30 and 35 mm) were modelled using a two-compartment radiofrequency ablation model. Different voltages were applied to seek the maximum target tissue necrosis volume for each target tissue size. The first roll-off occurrence or the standard ablation time (12 min) was taken as the sign for the termination of the RFA procedure. Four different maximum voltages without the roll-off occurrence were found for the four different sizes of target tissues (dxy = 20, 25, 30 and 35 mm), and they were 36.6, 35.4, 33.9 and 32.5 V, respectively. The target tissues with diameters of 20, 25 mm can be cleanly ablated at their own maximum voltages applied (MVA) but the same finding was not found for the 35-mm target tissue. For the target tissue with diameter of 30 mm, the 50 °C isothermal contour (IT50) result showed that the target tissue can be cleanly ablated, but the same result did not show in the Arrhenius damage model result. Furthermore, two optimal RFA protocols with a minimal thermal damage to the healthy tissues were found for the target tissues with diameters of 20 and 25 mm, respectively. The study suggests that target tissues of different sizes should be treated with different RFA protocols. The maximum target tissue volume was achieved with the MVA without the roll-off occurrence for each target tissue size when a constant RF power supply was used.

  1. Using four-dimensional computed tomography images to optimize the internal target volume when using volume-modulated arc therapy to treat moving targets.

    Science.gov (United States)

    Yakoumakis, Nikolaos; Winey, Brian; Killoran, Joseph; Mayo, Charles; Niedermayr, Thomas; Panayiotakis, George; Lingos, Tania; Court, Laurence

    2012-11-08

    In this work we used 4D dose calculations, which include the effects of shape deformations, to investigate an alternative approach to creating the ITV. We hypothesized that instead of needing images from all the breathing phases in the 4D CT dataset to create the outer envelope used for treatment planning, it is possible to exclude images from the phases closest to the inhale phase. We used 4D CT images from 10 patients with lung cancer. For each patient, we drew a gross tumor volume on the exhale-phase image and propagated this to the images from other phases in the 4D CT dataset using commercial image registration software. We created four different ITVs using the N phases closest to the exhale phase (where N = 10, 8, 7, 6). For each ITV contour, we created a volume-modulated arc therapy plan on the exhale-phase CT and normalized it so that the prescribed dose covered at least 95% of the ITV. Each plan was applied to CT images from each CT phase (phases 1-10), and the calculated doses were then mapped to the exhale phase using deformable registration. The effect of the motion was quantified using the dose to 95% of the target on the exhale phase (D95) and tumor control probability. For the three-dimensional and 4D dose calculations of the plan where N = 10, differences in the D95 value varied from 3% to 14%, with an average difference of 7%. For 9 of the 10 patients, the reduction in D95 was less than 5% if eight phases were used to create the ITV. For three of the 10 patients, the reduction in the D95 was less than 5% if seven phases were used to create the ITV. We were unsuccessful in creating a general rule that could be used to create the ITV. Some reduction (8/10 phases) was possible for most, but not all, of the patients, and the ITV reduction was small.

  2. Impact of systematic errors on DVH parameters of different OAR and target volumes in Intracavitary Brachytherapy (ICBT)

    International Nuclear Information System (INIS)

    Mourya, Ankur; Singh, Gaganpreet; Kumar, Vivek; Oinam, Arun S.

    2016-01-01

    Aim of this study is to analyze the impact of systematic errors on DVH parameters of different OAR and Target volumes in intracavitary brachytherapy (ICBT). To quantify the changes in dose-volume histogram parameters due to systematic errors in applicator reconstruction of brachytherapy planning, known errors in catheter reconstructions have to be introduced in applicator coordinate system

  3. FDG-PET/CT imaging for staging and target volume delineation in conformal radiotherapy of anal carcinoma

    International Nuclear Information System (INIS)

    Krengli, Marco; Inglese, Eugenio; Milia, Maria E; Turri, Lucia; Mones, Eleonora; Bassi, Maria C; Cannillo, Barbara; Deantonio, Letizia; Sacchetti, Gianmauro; Brambilla, Marco

    2010-01-01

    FDG-PET/CT imaging has an emerging role in staging and treatment planning of various tumor locations and a number of literature studies show that also the carcinoma of the anal canal may benefit from this diagnostic approach. We analyzed the potential impact of FDG-PET/CT in stage definition and target volume delineation of patients affected by carcinoma of the anal canal and candidates for curative radiotherapy. Twenty seven patients with biopsy proven anal carcinoma were enrolled. Pathology was squamous cell carcinoma in 20 cases, cloacogenic carcinoma in 3, adenocarcinoma in 2, and basal cell carcinoma in 2. Simulation was performed by PET/CT imaging with patient in treatment position. Gross Tumor Volume (GTV) and Clinical Target Volume (CTV) were drawn on CT and on PET/CT fused images. PET-GTV and PET-CTV were respectively compared to CT-GTV and CT-CTV by Wilcoxon rank test for paired data. PET/CT fused images led to change the stage in 5/27 cases (18.5%): 3 cases from N0 to N2 and 2 from M0 to M1 leading to change the treatment intent from curative to palliative in a case. Based on PET/CT imaging, GTV and CTV contours changed in 15/27 (55.6%) and in 10/27 cases (37.0%) respectively. PET-GTV and PET-CTV resulted significantly smaller than CT-GTV (p = 1.2 × 10 -4 ) and CT-CTV (p = 2.9 × 10 -4 ). PET/CT-GTV and PET/CT-CTV, that were used for clinical purposes, were significantly greater than CT-GTV (p = 6 × 10 -5 ) and CT-CTV (p = 6 × 10 -5 ). FDG-PET/CT has a potential relevant impact in staging and target volume delineation of the carcinoma of the anal canal. Clinical stage variation occurred in 18.5% of cases with change of treatment intent in 3.7%. The GTV and the CTV changed in shape and in size based on PET/CT imaging

  4. [Resistance to target-based therapy and its circumvention].

    Science.gov (United States)

    Nishio, Kazuto

    2004-07-01

    Intrinsic and acquired resistance to molecular target therapy critically limits the outcome of cancer treatments. Target levels including quantitative and gene alteration should be determinants for the resistance. Downstream of the target molecules, drug metabolism, and drug transport influences the tumor sensitivity to molecular target therapy. The mechanisms of resistance to antibody therapy have not been fully clarified. Correlative clinical studies using these biomarkers of resistance are extremely important for circumvention of clinical resistance to target based therapy.

  5. Measurement of Tumor Volumes Improves RECIST-Based Response Assessments in Advanced Lung Cancer1

    Science.gov (United States)

    Mozley, P David; Bendtsen, Claus; Zhao, Binsheng; Schwartz, Lawrence H; Thorn, Matthias; Rong, Yuanxin; Zhang, Luduan; Perrone, Andrea; Korn, René; Buckler, Andrew J

    2012-01-01

    OBJECTIVE: This study was designed to characterize the reproducibility of measurement for tumor volumes and their longest tumor diameters (LDs) and estimate the potential impact of using changes in tumor volumes instead of LDs as the basis for response assessments. METHODS: We studied patients with advanced lung cancer who have been observed longitudinally with x-ray computed tomography in a multinational trial. A total of 71 time points from 10 patients with 13 morphologically complex target lesions were analyzed. A total of 6461 volume measurements and their corresponding LDs were made by seven independent teams using their own work flows and image analysis tools. Interteam agreement and overall interrater concurrence were characterized. RESULTS: Interteam agreement between volume measurements was better than between LD measurements (ı = 0.945 vs 0.734, P = .005). The variability in determining the nadir was lower for volumes than for LDs (P = .005). Use of standard thresholds for the RECIST-based method and use of experimentally determined cutoffs for categorizing responses showed that volume measurements had a significantly greater sensitivity for detecting partial responses and disease progression. Earlier detection of progression would have led to earlier changes in patient management in most cases. CONCLUSIONS: Our findings indicate that measurement of changes in tumor volumes is adequately reproducible. Using tumor volumes as the basis for response assessments could have a positive impact on both patient management and clinical trials. More authoritative work to qualify or discard changes in volume as the basis for response assessments should proceed. PMID:22348172

  6. Dosimetric Advantages of Midventilation Compared With Internal Target Volume for Radiation Therapy of Pancreatic Cancer.

    Science.gov (United States)

    Lens, Eelco; van der Horst, Astrid; Versteijne, Eva; van Tienhoven, Geertjan; Bel, Arjan

    2015-07-01

    The midventilation (midV) approach can be used to take respiratory-induced pancreatic tumor motion into account during radiation therapy. In this study, the dosimetric consequences for organs at risk and tumor coverage of using a midV approach compared with using an internal target volume (ITV) were investigated. For each of the 18 patients, 2 treatment plans (25 × 2.0 Gy) were created, 1 using an ITV and 1 using a midV approach. The midV dose distribution was blurred using the respiratory-induced motion from 4-dimensional computed tomography. The resulting planning target volume (PTV) coverage for this blurred dose distribution was analyzed; PTV coverage was required to be at least V95% >98%. In addition, the change in PTV size and the changes in V10Gy, V20Gy, V30Gy, V40Gy, Dmean and D2cc for the stomach and for the duodenum were analyzed; differences were tested for significance using the Wilcoxon signed-rank test. Using a midV approach resulted in sufficient target coverage. A highly significant PTV size reduction of 13.9% (P<.001) was observed. Also, all dose parameters for the stomach and duodenum, except the D2cc of the duodenum, improved significantly (P≤.002). By using the midV approach to account for respiratory-induced tumor motion, a significant PTV reduction and significant dose reductions to the stomach and to the duodenum can be achieved when irradiating pancreatic tumors. Copyright © 2015 Elsevier Inc. All rights reserved.

  7. Dosimetric Advantages of Midventilation Compared With Internal Target Volume for Radiation Therapy of Pancreatic Cancer

    International Nuclear Information System (INIS)

    Lens, Eelco; Horst, Astrid van der; Versteijne, Eva; Tienhoven, Geertjan van; Bel, Arjan

    2015-01-01

    Purpose: The midventilation (midV) approach can be used to take respiratory-induced pancreatic tumor motion into account during radiation therapy. In this study, the dosimetric consequences for organs at risk and tumor coverage of using a midV approach compared with using an internal target volume (ITV) were investigated. Methods and Materials: For each of the 18 patients, 2 treatment plans (25 × 2.0 Gy) were created, 1 using an ITV and 1 using a midV approach. The midV dose distribution was blurred using the respiratory-induced motion from 4-dimensional computed tomography. The resulting planning target volume (PTV) coverage for this blurred dose distribution was analyzed; PTV coverage was required to be at least V 95% >98%. In addition, the change in PTV size and the changes in V 10Gy , V 20Gy , V 30Gy , V 40Gy , D mean and D 2cc for the stomach and for the duodenum were analyzed; differences were tested for significance using the Wilcoxon signed-rank test. Results: Using a midV approach resulted in sufficient target coverage. A highly significant PTV size reduction of 13.9% (P<.001) was observed. Also, all dose parameters for the stomach and duodenum, except the D 2cc of the duodenum, improved significantly (P≤.002). Conclusions: By using the midV approach to account for respiratory-induced tumor motion, a significant PTV reduction and significant dose reductions to the stomach and to the duodenum can be achieved when irradiating pancreatic tumors

  8. Dosimetric Advantages of Midventilation Compared With Internal Target Volume for Radiation Therapy of Pancreatic Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Lens, Eelco, E-mail: e.lens@amc.uva.nl; Horst, Astrid van der; Versteijne, Eva; Tienhoven, Geertjan van; Bel, Arjan

    2015-07-01

    Purpose: The midventilation (midV) approach can be used to take respiratory-induced pancreatic tumor motion into account during radiation therapy. In this study, the dosimetric consequences for organs at risk and tumor coverage of using a midV approach compared with using an internal target volume (ITV) were investigated. Methods and Materials: For each of the 18 patients, 2 treatment plans (25 × 2.0 Gy) were created, 1 using an ITV and 1 using a midV approach. The midV dose distribution was blurred using the respiratory-induced motion from 4-dimensional computed tomography. The resulting planning target volume (PTV) coverage for this blurred dose distribution was analyzed; PTV coverage was required to be at least V{sub 95%} >98%. In addition, the change in PTV size and the changes in V{sub 10Gy}, V{sub 20Gy}, V{sub 30Gy}, V{sub 40Gy}, D{sub mean} and D{sub 2cc} for the stomach and for the duodenum were analyzed; differences were tested for significance using the Wilcoxon signed-rank test. Results: Using a midV approach resulted in sufficient target coverage. A highly significant PTV size reduction of 13.9% (P<.001) was observed. Also, all dose parameters for the stomach and duodenum, except the D{sub 2cc} of the duodenum, improved significantly (P≤.002). Conclusions: By using the midV approach to account for respiratory-induced tumor motion, a significant PTV reduction and significant dose reductions to the stomach and to the duodenum can be achieved when irradiating pancreatic tumors.

  9. An analytic solution for calculating the beam intensity profiles useful to irradiate target volumes with bi-concave outlines

    Energy Technology Data Exchange (ETDEWEB)

    De Neve, W.; Derycke, S.; De Wagter, C. [Ghent Rijksuniversiteit (Belgium). Kliniek voor Radiotherapie en Kerngeneeskunde

    1995-12-01

    A heuristic planing procedure allowing to obtain a 3-dimensional conformal dose distribution in radiotherapy for target volumes with a bi-concave or multi-concave shape has been developed. The described method is tested on a phantom simulating a pelvic target, described by Brahme.

  10. The need for rotational margins in intensity-modulated radiotherapy and a new method for planning target volume design

    International Nuclear Information System (INIS)

    Langer, Mark Peter; Papiez, Lech; Spirydovich, Siarhei; Thai, Van

    2005-01-01

    Purpose: The effect of rotational errors on the coverage of clinical target volumes (CTVs) is examined. A new planning target volume (PTV) construction that considers the individual paths traced by movements of the target boundary points is developed. Methods and Materials: A standard uniform margin expansion was compared with a PTV constructed from the space swept out by a concave moving target. A new method formed the PTV by aggregating the separate convex hulls taken of the positions of the individual target boundary points in a sampling of CTV displacements. Results: A 0.5-cm uniform margin adequate for translations was inadequate given CTV rotation about a fixed off-center axis. A PTV formed of the target's swept-out area was 22% smaller than needed for coverage by a uniform margin, but computationally is not readily extended to translations combined with rotations about a shifting axis. Forming instead the union of convex hulls of the boundary points in a sampling of CTV displacements represented these movements in the PTV design and retained the target's concave shape. Conclusions: Planning target volumes should accommodate target rotation. The union of convex hulls of the boundary point positions in a sampling of displacements can effectively represent multiple sources of deviations while preserving target concavities

  11. Target recognition based on convolutional neural network

    Science.gov (United States)

    Wang, Liqiang; Wang, Xin; Xi, Fubiao; Dong, Jian

    2017-11-01

    One of the important part of object target recognition is the feature extraction, which can be classified into feature extraction and automatic feature extraction. The traditional neural network is one of the automatic feature extraction methods, while it causes high possibility of over-fitting due to the global connection. The deep learning algorithm used in this paper is a hierarchical automatic feature extraction method, trained with the layer-by-layer convolutional neural network (CNN), which can extract the features from lower layers to higher layers. The features are more discriminative and it is beneficial to the object target recognition.

  12. Panorama: a targeted proteomics knowledge base.

    Science.gov (United States)

    Sharma, Vagisha; Eckels, Josh; Taylor, Greg K; Shulman, Nicholas J; Stergachis, Andrew B; Joyner, Shannon A; Yan, Ping; Whiteaker, Jeffrey R; Halusa, Goran N; Schilling, Birgit; Gibson, Bradford W; Colangelo, Christopher M; Paulovich, Amanda G; Carr, Steven A; Jaffe, Jacob D; MacCoss, Michael J; MacLean, Brendan

    2014-09-05

    Panorama is a web application for storing, sharing, analyzing, and reusing targeted assays created and refined with Skyline,1 an increasingly popular Windows client software tool for targeted proteomics experiments. Panorama allows laboratories to store and organize curated results contained in Skyline documents with fine-grained permissions, which facilitates distributed collaboration and secure sharing of published and unpublished data via a web-browser interface. It is fully integrated with the Skyline workflow and supports publishing a document directly to a Panorama server from the Skyline user interface. Panorama captures the complete Skyline document information content in a relational database schema. Curated results published to Panorama can be aggregated and exported as chromatogram libraries. These libraries can be used in Skyline to pick optimal targets in new experiments and to validate peak identification of target peptides. Panorama is open-source and freely available. It is distributed as part of LabKey Server,2 an open source biomedical research data management system. Laboratories and organizations can set up Panorama locally by downloading and installing the software on their own servers. They can also request freely hosted projects on https://panoramaweb.org , a Panorama server maintained by the Department of Genome Sciences at the University of Washington.

  13. Variation in radiotherapy target volume definition, dose to organs at risk and clinical target volumes using anatomic (computed tomography) versus combined anatomic and molecular imaging (positron emission tomography/computed tomography): intensity-modulated radiotherapy delivered using a tomotherapy Hi Art machine: final results of the VortigERN study.

    Science.gov (United States)

    Chatterjee, S; Frew, J; Mott, J; McCallum, H; Stevenson, P; Maxwell, R; Wilsdon, J; Kelly, C G

    2012-12-01

    tumours. Also, PET/CT provided a smaller better-defined target volume when compared with CECT. PET/CT-based volumes could therefore be used for treatment planning and targeted dose painting in oropharyngeal cancers. Copyright © 2012. Published by Elsevier Ltd.

  14. Target volume delineation and treatment planning for particle therapy a practical guide

    CERN Document Server

    Leeman, Jonathan E; Cahlon, Oren; Sine, Kevin; Jiang, Guoliang; Lu, Jiade J; Both, Stefan

    2018-01-01

    This handbook is designed to enable radiation oncologists to treat patients appropriately and confidently by means of particle therapy. The orientation and purpose are entirely practical, in that the focus is on the physics essentials of delivery and treatment planning , illustration of the clinical target volume (CTV) and associated treatment planning for each major malignancy when using particle therapy, proton therapy in particular. Disease-specific chapters provide guidelines and concise knowledge on CTV selection and delineation and identify aspects that require the exercise of caution during treatment planning. The treatment planning techniques unique to proton therapy for each disease site are clearly described, covering beam orientation, matching/patching field techniques, robustness planning, robustness plan evaluation, etc. The published data on the use of particle therapy for a given disease site are also concisely reported. In addition to fully meeting the needs of radiation oncologists, this "kn...

  15. Evaluation of potential internal target volume of liver tumors using cine-MRI

    Energy Technology Data Exchange (ETDEWEB)

    Akino, Yuichi, E-mail: akino@radonc.med.osaka-u.ac.jp [Department of Radiation Oncology, Osaka University Graduate School of Medicine, Suita, Osaka 5650871, Japan and Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan); Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko [Miyakojima IGRT Clinic, Miyakojima-ku, Osaka 5340021 (Japan)

    2014-11-01

    Purpose: Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. Methods: The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas–Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV {sub Potential}). The concordance between ITV {sub Potential} and ITV estimated with 4DCT (ITV {sub 4DCT}) was evaluated using the Dice’s similarity coefficient (DSC). Results

  16. Evaluation of potential internal target volume of liver tumors using cine-MRI.

    Science.gov (United States)

    Akino, Yuichi; Oh, Ryoong-Jin; Masai, Norihisa; Shiomi, Hiroya; Inoue, Toshihiko

    2014-11-01

    Four-dimensional computed tomography (4DCT) is widely used for evaluating moving tumors, including lung and liver cancers. For patients with unstable respiration, however, the 4DCT may not visualize tumor motion properly. High-speed magnetic resonance imaging (MRI) sequences (cine-MRI) permit direct visualization of respiratory motion of liver tumors without considering radiation dose exposure to patients. Here, the authors demonstrated a technique for evaluating internal target volume (ITV) with consideration of respiratory variation using cine-MRI. The authors retrospectively evaluated six patients who received stereotactic body radiotherapy (SBRT) to hepatocellular carcinoma. Before acquiring planning CT, sagittal and coronal cine-MRI images were acquired for 30 s with a frame rate of 2 frames/s. The patient immobilization was conducted under the same condition as SBRT. Planning CT images were then acquired within 15 min from cine-MRI image acquisitions, followed by a 4DCT scan. To calculate tumor motion, the motion vectors between two continuous frames of cine-MRI images were calculated for each frame using the pyramidal Lucas-Kanade method. The target contour was delineated on one frame, and each vertex of the contour was shifted and copied onto the following frame using neighboring motion vectors. 3D trajectory data were generated with the centroid of the contours on sagittal and coronal images. To evaluate the accuracy of the tracking method, the motion of clearly visible blood vessel was analyzed with the motion tracking and manual detection techniques. The target volume delineated on the 50% (end-exhale) phase of 4DCT was translated with the trajectory data, and the distribution of the occupancy probability of target volume was calculated as potential ITV (ITV Potential). The concordance between ITV Potential and ITV estimated with 4DCT (ITV 4DCT) was evaluated using the Dice's similarity coefficient (DSC). The distance between blood vessel positions

  17. SU-E-T-287: Dose Verification On the Variation of Target Volume and Organ at Risk in Preradiation Chemotherapy IMRT for Nasopharyngeal Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, X; Kong, L; Wang, J; Hu, W; Chen, Z [Fudan University Shanghai Cancer Center, Shanghai, Shanghai (China)

    2015-06-15

    Purpose: To quantify the target volume and organ at risk of nasopharyngeal carcinoma (NPC) patients with preradiation chemotherapy based on CT scanned during intensity-modulated radiotherapy (IMRT), and recalculate the dose distribution. Methods: Seven patients with NPC and preradiation chemotherapy, treated with IMRT (35 to 37 fractions) were reviewed. Repeat CT scanning was required to all of the patients during the radiotherapy, and the number of repeat CTs varies from 2 to 6. The plan CT and repeat CT were generated by different CT scanner. To ensure crespectively on the same IMPT plan. The real dose distribution was calculated by deformable registration and weighted method in Raystation (v 4.5.1). The fraction of each dose is based on radiotherapy record. The volumetric and dose differences among these images were calculated for nascIpharyngeal tumor and retro-pharyngeal lymph nodes (GTV-NX), neck lymph nodes(GTV-ND), and parotid glands. Results: The volume variation in GTV-NX from CT1 to CT2 was 1.15±3.79%, and in GTV-LN −0.23±4.93%. The volume variation in left parotid from CT1 to CT2 was −6.79±11.91%, and in right parotid −3.92±8.80%. In patient 2, the left parotid volume were decreased remarkably, as a Result, the V30 and V40 of it were increased as well. Conclusion: The target volume of patients with NPC varied lightly during IMRT. It shows that preradiation chemotherapy can control the target volume variation and perform a good dose repeatability. Also, the decreasing volume of parotid in some patient might increase the dose of it, which might course potential complications.

  18. Iterative volume morphing and learning for mobile tumor based on 4DCT.

    Science.gov (United States)

    Mao, Songan; Wu, Huanmei; Sandison, George; Fang, Shiaofen

    2017-02-21

    During image-guided cancer radiation treatment, three-dimensional (3D) tumor volumetric information is important for treatment success. However, it is typically not feasible to image a patient's 3D tumor continuously in real time during treatment due to concern over excessive patient radiation dose. We present a new iterative morphing algorithm to predict the real-time 3D tumor volume based on time-resolved computed tomography (4DCT) acquired before treatment. An offline iterative learning process has been designed to derive a target volumetric deformation function from one breathing phase to another. Real-time volumetric prediction is performed to derive the target 3D volume during treatment delivery. The proposed iterative deformable approach for tumor volume morphing and prediction based on 4DCT is innovative because it makes three major contributions: (1) a novel approach to landmark selection on 3D tumor surfaces using a minimum bounding box; (2) an iterative morphing algorithm to generate the 3D tumor volume using mapped landmarks; and (3) an online tumor volume prediction strategy based on previously trained deformation functions utilizing 4DCT. The experimental performance showed that the maximum morphing deviations are 0.27% and 1.25% for original patient data and artificially generated data, which is promising. This newly developed algorithm and implementation will have important applications for treatment planning, dose calculation and treatment validation in cancer radiation treatment.

  19. Iterative volume morphing and learning for mobile tumor based on 4DCT

    Science.gov (United States)

    Mao, Songan; Wu, Huanmei; Sandison, George; Fang, Shiaofen

    2017-02-01

    During image-guided cancer radiation treatment, three-dimensional (3D) tumor volumetric information is important for treatment success. However, it is typically not feasible to image a patient’s 3D tumor continuously in real time during treatment due to concern over excessive patient radiation dose. We present a new iterative morphing algorithm to predict the real-time 3D tumor volume based on time-resolved computed tomography (4DCT) acquired before treatment. An offline iterative learning process has been designed to derive a target volumetric deformation function from one breathing phase to another. Real-time volumetric prediction is performed to derive the target 3D volume during treatment delivery. The proposed iterative deformable approach for tumor volume morphing and prediction based on 4DCT is innovative because it makes three major contributions: (1) a novel approach to landmark selection on 3D tumor surfaces using a minimum bounding box; (2) an iterative morphing algorithm to generate the 3D tumor volume using mapped landmarks; and (3) an online tumor volume prediction strategy based on previously trained deformation functions utilizing 4DCT. The experimental performance showed that the maximum morphing deviations are 0.27% and 1.25% for original patient data and artificially generated data, which is promising. This newly developed algorithm and implementation will have important applications for treatment planning, dose calculation and treatment validation in cancer radiation treatment.

  20. Technology transfer package on seismic base isolation - Volume III

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-14

    This Technology Transfer Package provides some detailed information for the U.S. Department of Energy (DOE) and its contractors about seismic base isolation. Intended users of this three-volume package are DOE Design and Safety Engineers as well as DOE Facility Managers who are responsible for reducing the effects of natural phenomena hazards (NPH), specifically earthquakes, on their facilities. The package was developed as part of DOE's efforts to study and implement techniques for protecting lives and property from the effects of natural phenomena and to support the International Decade for Natural Disaster Reduction. Volume III contains supporting materials not included in Volumes I and II.

  1. Study on spectrometer based upon volume holographic transmission grating

    Science.gov (United States)

    Huang, Zhen; Liu, Guodong; Ren, Zhong; Zeng, Lvming

    2010-10-01

    In this present paper, a spectrometer based upon axial transmissive optical structure with the volume-phase holographic (VPH) transmission grating technology is introduced. We give a physical insight for the structure and mechanism of photorefractive volume holographic gratings and theoretically analyze some important performance parameters of the spectrometer device using the coupled wave theory, which should be considered in the process of the following design for the device with volume phase holographic transmission gratings. The experimental results show, owing to its axial transmissive optical geometry and the perfect performance of the VPH transmission grating, the spectrometer based on the volume-phase holographic transmission grating has satisfactory high resolution and wavelength accuracy. It has great promise to be widely used in the future.

  2. Prediction of potential drug targets based on simple sequence properties

    Directory of Open Access Journals (Sweden)

    Lai Luhua

    2007-09-01

    Full Text Available Abstract Background During the past decades, research and development in drug discovery have attracted much attention and efforts. However, only 324 drug targets are known for clinical drugs up to now. Identifying potential drug targets is the first step in the process of modern drug discovery for developing novel therapeutic agents. Therefore, the identification and validation of new and effective drug targets are of great value for drug discovery in both academia and pharmaceutical industry. If a protein can be predicted in advance for its potential application as a drug target, the drug discovery process targeting this protein will be greatly speeded up. In the current study, based on the properties of known drug targets, we have developed a sequence-based drug target prediction method for fast identification of novel drug targets. Results Based on simple physicochemical properties extracted from protein sequences of known drug targets, several support vector machine models have been constructed in this study. The best model can distinguish currently known drug targets from non drug targets at an accuracy of 84%. Using this model, potential protein drug targets of human origin from Swiss-Prot were predicted, some of which have already attracted much attention as potential drug targets in pharmaceutical research. Conclusion We have developed a drug target prediction method based solely on protein sequence information without the knowledge of family/domain annotation, or the protein 3D structure. This method can be applied in novel drug target identification and validation, as well as genome scale drug target predictions.

  3. Consequences of tumor planning target volume reduction in treatment of T2-T4 laryngeal cancer.

    Science.gov (United States)

    Vugts, Cornelia A J M; Terhaard, Chris H J; Philippens, Marielle E P; Pameijer, Frank A; Kasperts, Nicolien; Raaijmakers, Cornelis P J

    2014-09-04

    Since lymph nodes volumes are generally four times the volume of the primary PTV, the advantage of using tight margins around the primary PTV is not clear. Therefore treatment margins of T2-T4 laryngeal carcinoma for IMRT are generally chosen in such a way that the PTV is comparable to that in conventional radiotherapy. The aim of this study is to quantify the effect of volume reduction of the primary PTV of T2-T4 laryngeal carcinoma with regard to late toxicity despite elective irradiation of lymph node levels II to IV. Two treatment plans based on conservative (GTV-PTV = 15 mm and 20 mm cranial), and on evidence-based tight margins (GTV-PTV = 8 mm) were calculated for 16 patients. Toxicity effects were estimated based on the dose distributions. Compared to conservative margins, using tight margins resulted in: 1) significant reduction of the normal tissue complication probability (NTCP) for swallowing muscles and submandibular glands, 2) significant reduction of the mean dose in all organs at risk (OAR), 3) a mean dose smaller than 60 Gy for all OARs except for the laryngeal cartilages. When the lymph node levels II to IV were prescribed with an elective dose, an NTCP reduction of 53% for the swallowing muscles and of 23% for the submandibular glands was found by using tight instead of conservative margins. When positive nodes were present, NTCP reduction amounted to 29% and 15%, respectively. There is a potential benefit in realizing evidence-based tight margins for laryngeal cancer patients despite elective irradiation of lymph node levels II to IV.

  4. Dose escalation to high-risk sub-volumes based on non-invasive imaging of hypoxia and glycolytic activity in canine solid tumors

    DEFF Research Database (Denmark)

    Clausen, Malene M.; Hansen, Anders Elias; af Rosenschold, Per Munck

    2013-01-01

    defined by a threshold based method. FDG sub-volumes were delineated at 40% (FDG40) and 50% (FDG50) of SUVmax. The size of sub-volumes, intersection and biological target volume (BTV) were measured in a treatment planning software. By varying the average dose prescription to the tumor from 66 to 85 Gy...

  5. Prospective Randomized Double-Blind Pilot Study of Site-Specific Consensus Atlas Implementation for Rectal Cancer Target Volume Delineation in the Cooperative Group Setting

    International Nuclear Information System (INIS)

    Fuller, Clifton D.; Nijkamp, Jasper; Duppen, Joop C.; Rasch, Coen R.N.; Thomas, Charles R.; Wang, Samuel J.; Okunieff, Paul; Jones, William E.; Baseman, Daniel; Patel, Shilpen; Demandante, Carlo G.N.; Harris, Anna M.; Smith, Benjamin D.; Katz, Alan W.; McGann, Camille

    2011-01-01

    Purpose: Variations in target volume delineation represent a significant hurdle in clinical trials involving conformal radiotherapy. We sought to determine the effect of a consensus guideline-based visual atlas on contouring the target volumes. Methods and Materials: A representative case was contoured (Scan 1) by 14 physician observers and a reference expert with and without target volume delineation instructions derived from a proposed rectal cancer clinical trial involving conformal radiotherapy. The gross tumor volume (GTV), and two clinical target volumes (CTVA, including the internal iliac, presacral, and perirectal nodes, and CTVB, which included the external iliac nodes) were contoured. The observers were randomly assigned to receipt (Group A) or nonreceipt (Group B) of a consensus guideline and atlas for anorectal cancers and then instructed to recontour the same case/images (Scan 2). Observer variation was analyzed volumetrically using the conformation number (CN, where CN = 1 equals total agreement). Results: Of 14 evaluable contour sets (1 expert and 7 Group A and 6 Group B observers), greater agreement was found for the GTV (mean CN, 0.75) than for the CTVs (mean CN, 0.46-0.65). Atlas exposure for Group A led to significantly increased interobserver agreement for CTVA (mean initial CN, 0.68, after atlas use, 0.76; p = .03) and increased agreement with the expert reference (initial mean CN, 0.58; after atlas use, 0.69; p = .02). For the GTV and CTVB, neither the interobserver nor the expert agreement was altered after atlas exposure. Conclusion: Consensus guideline atlas implementation resulted in a detectable difference in interobserver agreement and a greater approximation of expert volumes for the CTVA but not for the GTV or CTVB in the specified case. Visual atlas inclusion should be considered as a feature in future clinical trials incorporating conformal RT.

  6. Prospective randomized double-blind pilot study of site-specific consensus atlas implementation for rectal cancer target volume delineation in the cooperative group setting

    Science.gov (United States)

    Fuller, Clifton D.; Nijkamp, Jasper; Duppen, Joop; Rasch, Coen R.N.; Thomas, Charles R.; Wang, Samuel J.; Okunieff, Paul; Jones, William E.; Baseman, Daniel; Patel, Shilpen; Demandante, Carlo G. N.; Harris, Anna M.; Smith, Benjamin D.; Katz, Alan W.; McGann, Camille; Harper, Jennifer L.; Chang, Daniel T.; Smalley, Stephen; Marshall, David T.; Goodman, Karyn A.; Papanikolaou, Niko; Kachnic, Lisa A.

    2010-01-01

    Purpose Variation in target volume delineation represents a significant hurdle in clinical trials involving conformal radiotherapy. We sought to determine the impact of a consensus guideline-based visual atlas on contouring of target volumes. Methods A representative case and target volume delineation instructions derived from a proposed rectal cancer clinical trial involving conformal radiotherapy were contoured (Scan1) by 14 physician observers and a reference expert. Gross tumor volume (GTV), and 2 clinical target volumes (CTVA, comprising internal iliac, pre-sacral, and peri-rectal nodes, and CTVB, external iliac nodes) were contoured. Observers were randomly assigned to receipt (Group_A) /non-receipt (Group_B) of a consensus guideline and atlas for anorectal cancers, then instructed to re-contour the same case/images (Scan2). Observer variation was analyzed volumetrically using conformation number (CN, where CN=1 equals a total agreement). Results In 14 evaluable contour sets (1 expert, 7 Group_A, 6 Group_B), there was greater agreement for GTV (mean CN 0.75) than CTVs (mean CN 0.46–0.65). Atlas exposure for Group_A led to a significant increased inter-observer agreement for CTVA (mean initial CN 0.68, post-atlas 0.76; p=0.03), as well as increased agreement with the expert reference (initial mean CN 0.58, 0.69 post-atlas; p=0.02). For GTV and CTVB, neither inter-observer nor expert agreement was altered after atlas exposure. Conclusion Consensus guideline atlas implementation resulted in a detectable difference in inter-observer agreement and greater approximation of expert volumes for CTVA, but not GTV or CTVB, in the specified case. Visual atlas inclusion should be considered as a feature in future clinical trials incorporating conformal radiotherapy. PMID:20400244

  7. Optimization of radiotherapy to target volumes with concave outlines: target-dose homogenization and selective sparing of critical structures by constrained matrix inversion

    Energy Technology Data Exchange (ETDEWEB)

    Colle, C.; Van den Berge, D.; De Wagter, C.; Fortan, L.; Van Duyse, B.; De Neve, W.

    1995-12-01

    The design of 3D-conformal dose distributions for targets with concave outlines is a technical challenge in conformal radiotherapy. For these targets, it is impossible to find beam incidences for which the target volume can be isolated from the tissues at risk. Commonly occurring examples are most thyroid cancers and the targets located at the lower neck and upper mediastinal levels related to some head and neck. A solution to this problem was developed, using beam intensity modulation executed with a multileaf collimator by applying a static beam-segmentation technique. The method includes the definition of beam incidences and beam segments of specific shape as well as the calculation of segment weights. Tests on Sherouse`s GRATISTM planning system allowed to escalate the dose to these targets to 65-70 Gy without exceeding spinal cord tolerance. Further optimization by constrained matrix inversion was investigated to explore the possibility of further dose escalation.

  8. A computational network analysis based on targets of antipsychotic agents.

    Science.gov (United States)

    Gao, Lei; Feng, Shuo; Liu, Zhao-Yuan; Wang, Jiu-Qiang; Qi, Ke-Ke; Wang, Kai

    2018-03-01

    Currently, numerous antipsychotic agents have been developed in the area of pharmacological treatment of schizophrenia. However, the molecular mechanism underlying multi targets of antipsychotics were yet to be explored. In this study we performed a computational network analysis based on targets of antipsychotic agents. We retrieved a total of 96 targets from 56 antipsychotic agents. By expression enrichment analysis, we identified that the expressions of antipsychotic target genes were significantly enriched in liver, brain, blood and corpus striatum. By protein-protein interaction (PPI) network analysis, a PPI network with 77 significantly interconnected target genes was generated. By historeceptomics analysis, significant brain region specific target-drug interactions were identified in targets of dopamine receptors (DRD1-Olanzapine in caudate nucleus and pons (P-valueantipsychotic targets and insights for molecular mechanism of antipsychotic agents. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Tracking target objects orbiting earth using satellite-based telescopes

    Science.gov (United States)

    De Vries, Willem H; Olivier, Scot S; Pertica, Alexander J

    2014-10-14

    A system for tracking objects that are in earth orbit via a constellation or network of satellites having imaging devices is provided. An object tracking system includes a ground controller and, for each satellite in the constellation, an onboard controller. The ground controller receives ephemeris information for a target object and directs that ephemeris information be transmitted to the satellites. Each onboard controller receives ephemeris information for a target object, collects images of the target object based on the expected location of the target object at an expected time, identifies actual locations of the target object from the collected images, and identifies a next expected location at a next expected time based on the identified actual locations of the target object. The onboard controller processes the collected image to identify the actual location of the target object and transmits the actual location information to the ground controller.

  10. 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.

  11. Target volumes in gastric cancer radiation therapy; Les volumes-cibles de la radiotherapie des adenocarcinomes gastriques

    Energy Technology Data Exchange (ETDEWEB)

    Caudry, M.; Maire, J.P. [Hopital Saint Andre, Service de Cancerologie, 33 - Bordeaux (France); Ratoanina, J.L.; Escarmant, P. [Hopital Clarac, Service de Radiotherapie et de Cancerologie, 97 - Fort de France (France)

    2001-10-01

    The spread of gastric adenocarcinoma may follow three main patterns: hemato-genic, lymphatic and intraperitoneal. A GTV should be considered in preoperative or exclusive radiation therapy. After non-radical surgery, a 'residual GTV' will be defined with the help of the surgeon. The CTV encompasses three intricated volumes. a) A 'tumor bed' volume. After radical surgery, local recurrences appear as frequent as distant metastases. The risk depends upon the depth of parietal invasion and the nodal status. Parietal infiltration may extend beyond macroscopic limits of the tumor, especially in dinitis plastica. Therefore this volume will include: the tumor and the remaining stomach or their 'bed of resection', a part of the transverse colon, the duodenum, the pancreas and the troncus of the portal vein. In postoperative RT, this CTV also includes the jejuno-gastric or jejuno-esophageal anastomosis. b) A peritoneal volume. For practical purposes, two degrees of spread must be considered: (1) contiguous microscopic extension from deeply invasive T3 and T4 tumors, that remain amenable to local sterilization with doses of 45-50 Gy, delivered in a CTV including the peritoneal cavity at the level of the gastric bed, and under the parietal incision; (2) true 'peritoneal carcinomatosis', with widespread seeds, where chemotherapy (systemic or intraperitoneal) is more appropriate. c) A lymphatic volume including the lymph node groups 1 to 16 of the Japanese classification. This volume must encompass the hepatic pedicle and the splenic hilum. In proximal tumors, it is possible to restrict the lover part of the CTV to the lymphatic volume, and therefore to avoid irradiation of large intestinal and renal volumes. In distal and proximal tumors, involvement of resection margins is of poor prognosis -a radiation boost must be delivered at this level. The CTV in tumors of the cardia should encompass the lover part of the thoracic esophagus and the

  12. Complementary Approaches to Existing Target Based Drug Discovery for Identifying Novel Drug Targets

    Directory of Open Access Journals (Sweden)

    Suhas Vasaikar

    2016-11-01

    Full Text Available In the past decade, it was observed that the relationship between the emerging New Molecular Entities and the quantum of R&D investment has not been favorable. There might be numerous reasons but few studies stress the introduction of target based drug discovery approach as one of the factors. Although a number of drugs have been developed with an emphasis on a single protein target, yet identification of valid target is complex. The approach focuses on an in vitro single target, which overlooks the complexity of cell and makes process of validation drug targets uncertain. Thus, it is imperative to search for alternatives rather than looking at success stories of target-based drug discovery. It would be beneficial if the drugs were developed to target multiple components. New approaches like reverse engineering and translational research need to take into account both system and target-based approach. This review evaluates the strengths and limitations of known drug discovery approaches and proposes alternative approaches for increasing efficiency against treatment.

  13. Daily online localization using implanted fiducial markers and its impact on planning target volume for carcinoma prostate.

    Science.gov (United States)

    Khosa, Robin; Nangia, Sapna; Chufal, Kundan S; Ghosh, D; Kaul, Rakesh; Sharma, Lalit

    2010-01-01

    Aim of the study was to assess prostate motion on daily basis with respect to setup and to compare the shifts based on bony anatomy and gold fiducial markers. Gold fiducial markers were inserted in prostate under U/S guidance and daily portal images were taken and compared with digitally reconstructed images, both using bony landmarks and fiducial markers as reference. A dose of 2 MU was given for two orthogonal images daily. The mean and standard deviation of displacement using gold seeds and bone were calculated. Systematic and random errors were generated. The planning target volume (PTV) was calculated using the Van Herk formula. A total of 180 portal images from 10 patients were studied. The mean displacement along x, y and z axes was 1.67 mm, 3.58 mm, and 1.76 mm using fiducial markers and 2.12 mm, 3.47 mm, and 2.09 mm using bony landmarks, respectively. The mean internal organ motion was 1.23 mm (+1.45), 3.11 mm (+2.69 mm); and 1.87 mm (+1.67 mm) along x, y and z axes, respectively. The PTV to account for prostate motion if daily matching was not done was 4.64 mm, 10.41 mm and 4.40 mm along lateral, superoinferior, and anteroposterior directions, respectively. If bony landmarks were used for daily matching, margins of 3.61 mm, 7.31 mm, and 4.72 mm in lateral, superoinferior, and anteroposterior directions should be added to the clinical target volume. Daily alignment using gold fiducial markers is an effective method of localizing prostate displacement. It provides the option of reducing margins, thus limiting normal tissue toxicity and allowing the possibility of dose escalation for better long-term control.

  14. 3D Modeling and Visualization of Geology Volume based on Geophysical Field Data

    Directory of Open Access Journals (Sweden)

    Min Qi

    2007-10-01

    Full Text Available 3D modeling and visualization of geology volume is very important to interpret accurately and locate subsurface geology volume for mining exploration and deep prospecting. However, it faces a lack of information because the target area is usually unexplored and lacks geological data. This paper presents our experience in applying a 3D model of geology volume based on geophysics. This work has researched and developed a 3D visualization system. It is based on an OO (orientated object approach and modular programming, uses the C++ language and Microsoft .NET platform. This system has built first a high resistivity method and MT database. The system uses irregular tetrahedrons to construct its model and then finally has built the 3D geological model itself.

  15. Nanopore-Based Target Sequence Detection.

    Directory of Open Access Journals (Sweden)

    Trevor J Morin

    Full Text Available The promise of portable diagnostic devices relies on three basic requirements: comparable sensitivity to established platforms, inexpensive manufacturing and cost of operations, and the ability to survive rugged field conditions. Solid state nanopores can meet all these requirements, but to achieve high manufacturing yields at low costs, assays must be tolerant to fabrication imperfections and to nanopore enlargement during operation. This paper presents a model for molecular engineering techniques that meets these goals with the aim of detecting target sequences within DNA. In contrast to methods that require precise geometries, we demonstrate detection using a range of pore geometries. As a result, our assay model tolerates any pore-forming method and in-situ pore enlargement. Using peptide nucleic acid (PNA probes modified for conjugation with synthetic bulk-adding molecules, pores ranging 15-50 nm in diameter are shown to detect individual PNA-bound DNA. Detection of the CFTRΔF508 gene mutation, a codon deletion responsible for ∼66% of all cystic fibrosis chromosomes, is demonstrated with a 26-36 nm pore size range by using a size-enhanced PNA probe. A mathematical framework for assessing the statistical significance of detection is also presented.

  16. Integration of three-dimensional magnetic resonance spectrometry to the irradiation treatment plan for glioblastomas: definition of new target volumes; Integration de la spectrometrie par resonance magnetique tridimensionnelle au plan de traitement par irradiation des glioblastomes: definition de nouveaux volumes cibles

    Energy Technology Data Exchange (ETDEWEB)

    Ken, S.; Vieillevigne, L.; Cohen-Jonathan, E.M.; Laprie, A. [Departement de radiotherapie, institut Claudius-Regaud, 31 - Toulouse (France); Ken, S.; Franceries, X.; Lotterie, J.A.; Lubrano, V.; Catalaa, I.; Celsis, P.; Berry, I.; Laprie, A. [Inserm UMR 825 Imagerie cerebrale et handicaps neurologiques, 31 - Toulouse (France); Lotterie, J.A.; Lubrano, V.; Berry, I. [Departement de biophysique, centre hospitalier universitaire de Rangueil, 31 - Toulouse (France); Catalaa, I. [Departement de radiologie, centre hospitalier universitaire de Purpan, 31 - Toulouse (France)

    2010-10-15

    Based on a clinic trial, the authors report the definition of a new reliable and reproducible method to delimit and integrate targets to the treatment plan which are specific to magnetic resonance spectrometry imagery for the radiotherapy of glioblastomas, in order to perform a treatment by intensity-modulated conformational radiotherapy (IMRT). A weighted conventional MRI has been performed before radiotherapy. The importation of anatomic-metabolic images into the dose planning system comprises two steps: normalization on the whole volume of magnetic resonance spectrometry imagery, and segmentation of target volumes specific to spectrometry anomalies. This integration of target volumes is thus facilitated. Short communication

  17. Proposed definition of the vaginal cuff and paracolpium clinical target volume in postoperative uterine cervical cancer.

    Science.gov (United States)

    Murakami, Naoya; Norihisa, Yoshiki; Isohashi, Fumiaki; Murofushi, Keiko; Ariga, Takuro; Kato, Tomoyasu; Inaba, Koji; Okamoto, Hiroyuki; Ito, Yoshinori; Toita, Takafumi; Itami, Jun

    2016-01-01

    The aim of this study was to develop an appropriate definition for vaginal cuff and paracolpium clinical target volume (CTV) for postoperative intensity modulated radiation therapy in patients with uterine cervical cancer. A working subgroup was organized within the Radiation Therapy Study Group of the Japan Clinical Oncology Group to develop a definition for the postoperative vaginal cuff and paracolpium CTV in December 2013. The group consisted of 5 radiation oncologists who specialized in gynecologic oncology and a gynecologic oncologist. A comprehensive literature review that included anatomy, surgery, and imaging fields was performed and was followed by multiple discreet face-to-face discussions and e-mail messages before a final consensus was reached. Definitions for the landmark structures in all directions that demarcate the vaginal cuff and paracolpium CTV were decided by consensus agreement of the working group. A table was created that showed boundary structures of the vaginal cuff and paracolpium CTV in each direction. A definition of the postoperative cervical cancer vaginal cuff and paracolpium CTV was developed. It is expected that this definition guideline will serve as a template for future radiation therapy clinical trial protocols, especially protocols involving intensity modulated radiation therapy. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

  18. Target based drug design - a reality in virtual sphere.

    Science.gov (United States)

    Verma, Saroj; Prabhakar, Yenamandra S

    2015-01-01

    The target based drug design approaches are a series of computational procedures, including visualization tools, to support the decision systems of drug design/discovery process. In the essence of biological targets shaping the potential lead/drug molecules, this review presents a comprehensive position of different components of target based drug design which include target identification, protein modeling, molecular dynamics simulations, binding/catalytic sites identification, docking, virtual screening, fragment based strategies, substructure treatment of targets in tackling drug resistance, in silico ADMET, structural vaccinology, etc along with the key issues involved therein and some well investigated case studies. The concepts and working of these procedures are critically discussed to arouse interest and to advance the drug research.

  19. miRNA-target prediction based on transcriptional regulation

    Directory of Open Access Journals (Sweden)

    Fujiwara Toyofumi

    2013-02-01

    Full Text Available Abstract Background microRNAs (miRNAs are tiny endogenous RNAs that have been discovered in animals and plants, and direct the post-transcriptional regulation of target mRNAs for degradation or translational repression via binding to the 3'UTRs and the coding exons. To gain insight into the biological role of miRNAs, it is essential to identify the full repertoire of mRNA targets (target genes. A number of computer programs have been developed for miRNA-target prediction. These programs essentially focus on potential binding sites in 3'UTRs, which are recognized by miRNAs according to specific base-pairing rules. Results Here, we introduce a novel method for miRNA-target prediction that is entirely independent of existing approaches. The method is based on the hypothesis that transcription of a miRNA and its target genes tend to be co-regulated by common transcription factors. This hypothesis predicts the frequent occurrence of common cis-elements between promoters of a miRNA and its target genes. That is, our proposed method first identifies putative cis-elements in a promoter of a given miRNA, and then identifies genes that contain common putative cis-elements in their promoters. In this paper, we show that a significant number of common cis-elements occur in ~28% of experimentally supported human miRNA-target data. Moreover, we show that the prediction of human miRNA-targets based on our method is statistically significant. Further, we discuss the random incidence of common cis-elements, their consensus sequences, and the advantages and disadvantages of our method. Conclusions This is the first report indicating prevalence of transcriptional regulation of a miRNA and its target genes by common transcription factors and the predictive ability of miRNA-targets based on this property.

  20. Can FDG-PET assist in radiotherapy target volume definition of metastatic lymph nodes in head-and-neck cancer?

    International Nuclear Information System (INIS)

    Schinagl, Dominic A.X.; Hoffmann, Aswin L.; Vogel, Wouter V.; Dalen, Jorn A. van; Verstappen, Suzan M.M.; Oyen, Wim J.G.; Kaanders, Johannes H.A.M.

    2009-01-01

    Background and purpose: The role of FDG-PET in radiotherapy target volume definition of the neck was evaluated by comparing eight methods of FDG-PET segmentation to the current CT-based practice of lymph node assessment in head-and-neck cancer patients. Materials and methods: Seventy-eight head-and-neck cancer patients underwent coregistered CT- and FDG-PET scans. Lymph nodes were classified as 'enlarged' if the shortest axial diameter on CT was ≥10 mm, and as 'marginally enlarged' if it was 7-10 mm. Subsequently, lymph nodes were assessed on FDG-PET applying eight segmentation methods: visual interpretation (PET VIS ), applying fixed thresholds at a standardized uptake value (SUV) of 2.5 and at 40% and 50% of the maximum signal intensity of the primary tumor (PET SUV , PET 40% , PET 50% ) and applying a variable threshold based on the signal-to-background ratio (PET SBR ). Finally, PET 40%N , PET 50%N and PET SBRN were acquired using the signal of the lymph node as the threshold reference. Results: Of 108 nodes classified as 'enlarged' on CT, 75% were also identified by PET VIS , 59% by PET 40% , 43% by PET 50% and 43% by PET SBR . Of 100 nodes classified as 'marginally enlarged', only a minority were visualized by FDG-PET. The respective numbers were 26%, 10%, 7% and 8% for PET VIS , PET 40% , PET 50% and PET SBR . PET 40%N , PET 50%N and PET SBRN , respectively, identified 66%, 82% and 96% of the PET VIS -positive nodes. Conclusions: Many lymph nodes that are enlarged and considered metastatic by standard CT-based criteria appear to be negative on FDG-PET scan. Alternately, a small proportion of marginally enlarged nodes are positive on FDG-PET scan. However, the results are largely dependent on the PET segmentation tool used, and until proper validation FDG-PET is not recommended for target volume definition of metastatic lymph nodes in routine practice.

  1. A novel correction factor based on extended volume to complement the conformity index.

    Science.gov (United States)

    Jin, F; Wang, Y; Wu, Y-Z

    2012-08-01

    We propose a modified conformity index (MCI), based on extended volume, that improves on existing indices by correcting for the insensitivity of previous conformity indices to reference dose shape to assess the quality of high-precision radiation therapy and present an evaluation of its application. In this paper, the MCI is similar to the conformity index suggested by Paddick (CI(Paddick)), but with a different correction factor. It is shown for three cases: with an extended target volume, with an extended reference dose volume and without an extended volume. Extended volume is generated by expanding the original volume by 0.1-1.1 cm isotropically. Focusing on the simulation model, measurements of MCI employ a sphere target and three types of reference doses: a sphere, an ellipsoid and a cube. We can constrain the potential advantage of the new index by comparing MCI with CI(Paddick). The measurements of MCI in head-neck cancers treated with intensity-modulated radiation therapy and volumetric-modulated arc therapy provide a window on its clinical practice. The results of MCI for a simulation model and clinical practice are presented and the measurements are corrected for limited spatial resolution. The three types of MCI agree with each other, and comparisons between the MCI and CI(Paddick) are also provided. The results from our analysis show that the proposed MCI can provide more objective and accurate conformity measurement for high-precision radiation therapy. In combination with a dose-volume histogram, it will be a more useful conformity index.

  2. Determining optimal planning target volume and image guidance policy for post-prostatectomy intensity modulated radiotherapy.

    Science.gov (United States)

    Bell, Linda J; Cox, Jennifer; Eade, Thomas; Rinks, Marianne; Herschtal, Alan; Kneebone, Andrew

    2015-07-26

    There is limited information available on the optimal Planning Target Volume (PTV) expansions and image guidance for post-prostatectomy intensity modulated radiotherapy (PP-IMRT). As the prostate bed does not move in a uniform manner, there is a rationale for anisotropic PTV margins with matching to soft tissue. The aim of this study is to find the combination of PTV expansion and image guidance policy for PP-IMRT that provides the best balance of target coverage whilst minimising dose to the organs at risk. The Cone Beam CT (CBCT) images (n = 377) of 40 patients who received PP-IMRT with daily online alignment to bony anatomy (BA) were reviewed. Six different PTV expansions were assessed: 3 published PTV expansions (0.5 cm uniform, 1 cm uniform, and 1 + 0.5 cm posterior) and 3 further anisotropic PTV expansions (Northern Sydney Cancer Centre (NSCC), van Herk, and smaller anisotropic). Each was assessed for size, bladder and rectum coverage and geographic miss. Each CBCT was rematched using a superior soft tissue (SST) and averaged soft tissue (AST) match. Potential geographic miss was assessed using all PTV expansions except the van Herk margin. The 0.5 cm uniform expansion yielded the smallest PTV (median volume = 222.3 cc) and the 1 cm uniform expansion yielded the largest (361.7 cc). The Van Herk expansion includes the largest amount of bladder (28.0 %) and rectum (36.0 %) and the 0.5 cm uniform expansion the smallest (17.1 % bladder; 10.2 % rectum). The van Herk PTV expansion had the least geographic miss with BA matching (4.2 %) and the 0.5 cm uniform margin (28.4 %) the greatest. BA matching resulted in the highest geographic miss rate for all PTVs, followed by SST matching and AST matching. Changing from BA to an AST match decreases potential geographic miss by half to two thirds, depending on the PTV expansion, to image guidance policy for PP-IMRT is daily average soft tissue matching using CBCT scans with a small anisotropic PTV expansion of 0

  3. Gross tumor volume and clinical target volume in prostate cancer: How do satellites relate to the index lesion.

    Science.gov (United States)

    Hollmann, Birgit G; van Triest, Baukelien; Ghobadi, Ghazaleh; Groenendaal, Greetje; de Jong, Jeroen; van der Poel, Henk G; van der Heide, Uulke A

    2015-04-01

    There is an increasing interest for dose differentiation in prostate radiotherapy. The purpose of our study was to analyze the spatial distribution of tumor satellites inside the prostate. 61 prostatectomy specimens were stained with H&E. Tumor regions were delineated by the uro-pathologist. Volumes, distances and cell densities of all delineated tumor regions were measured and further analyzed. Multifocal disease was seen in 84% of the patients. The median number of tumor foci was 3. The median distance between the index lesion and the satellites was 1.0 cm, with a maximum of 4.4 cm. The index lesions accounted for 88% of the total tumor volume. The contribution of tumor focisatellites, regardless of size, were significantly higher than that of the prostate. Satellites do not appear in a limited margin around the index lesion (GTV). Consequently, a fixed CTV margin would not effectively cover all satellites. Thus if the aim is to treat all tumor foci, the entire prostate gland should be considered CTV. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  4. Vision-Based Target Finding and Inspection of a Ground Target Using a Multirotor UAV System

    Directory of Open Access Journals (Sweden)

    Ajmal Hinas

    2017-12-01

    Full Text Available In this paper, a system that uses an algorithm for target detection and navigation and a multirotor Unmanned Aerial Vehicle (UAV for finding a ground target and inspecting it closely is presented. The system can also be used for accurate and safe delivery of payloads or spot spraying applications in site-specific crop management. A downward-looking camera attached to a multirotor is used to find the target on the ground. The UAV descends to the target and hovers above the target for a few seconds to inspect the target. A high-level decision algorithm based on an OODA (observe, orient, decide, and act loop was developed as a solution to address the problem. Navigation of the UAV was achieved by continuously sending local position messages to the autopilot via Mavros. The proposed system performed hovering above the target in three different stages: locate, descend, and hover. The system was tested in multiple trials, in simulations and outdoor tests, from heights of 10 m to 40 m. Results show that the system is highly reliable and robust to sensor errors, drift, and external disturbance.

  5. Vision-Based Target Finding and Inspection of a Ground Target Using a Multirotor UAV System.

    Science.gov (United States)

    Hinas, Ajmal; Roberts, Jonathan M; Gonzalez, Felipe

    2017-12-17

    In this paper, a system that uses an algorithm for target detection and navigation and a multirotor Unmanned Aerial Vehicle (UAV) for finding a ground target and inspecting it closely is presented. The system can also be used for accurate and safe delivery of payloads or spot spraying applications in site-specific crop management. A downward-looking camera attached to a multirotor is used to find the target on the ground. The UAV descends to the target and hovers above the target for a few seconds to inspect the target. A high-level decision algorithm based on an OODA (observe, orient, decide, and act) loop was developed as a solution to address the problem. Navigation of the UAV was achieved by continuously sending local position messages to the autopilot via Mavros. The proposed system performed hovering above the target in three different stages: locate, descend, and hover. The system was tested in multiple trials, in simulations and outdoor tests, from heights of 10 m to 40 m. Results show that the system is highly reliable and robust to sensor errors, drift, and external disturbance.

  6. Information management data base for fusion target fabrication processes

    International Nuclear Information System (INIS)

    Reynolds, J.

    1983-01-01

    A computer-based data management system has been developed to handle data associated with target fabrication processes including glass microballoon characterization, gas filling, materials coating, and storage locations. The system provides automatic data storage and computation, flexible data entry procedures, fast access, automated report generation, and secure data transfer. It resides on a CDC CYBER 175 computer and is compatible with the CDC data base language Query Update, but is based on custom fortran software interacting directly with the CYBER's file management system. The described data base maintains detailed, accurate, and readily available records of fusion targets information

  7. Technology transfer package on seismic base isolation - Volume I

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-14

    This Technology Transfer Package provides some detailed information for the U.S. Department of Energy (DOE) and its contractors about seismic base isolation. Intended users of this three-volume package are DOE Design and Safety Engineers as well as DOE Facility Managers who are responsible for reducing the effects of natural phenomena hazards (NPH), specifically earthquakes, on their facilities. The package was developed as part of DOE's efforts to study and implement techniques for protecting lives and property from the effects of natural phenomena and to support the International Decade for Natural Disaster Reduction. Volume I contains the proceedings of the Workshop on Seismic Base Isolation for Department of Energy Facilities held in Marina Del Rey, California, May 13-15, 1992.

  8. Technology transfer package on seismic base isolation - Volume II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-02-14

    This Technology Transfer Package provides some detailed information for the U.S. Department of Energy (DOE) and its contractors about seismic base isolation. Intended users of this three-volume package are DOE Design and Safety Engineers as well as DOE Facility Managers who are responsible for reducing the effects of natural phenomena hazards (NPH), specifically earthquakes, on their facilities. The package was developed as part of DOE's efforts to study and implement techniques for protecting lives and property from the effects of natural phenomena and to support the International Decade for Natural Disaster Reduction. Volume II contains the proceedings for the Short Course on Seismic Base Isolation held in Berkeley, California, August 10-14, 1992.

  9. Will weight loss cause significant dosimetric changes of target volumes and organs at risk in nasopharyngeal carcinoma treated with intensity-modulated radiation therapy?

    International Nuclear Information System (INIS)

    Chen, Chuanben; Fei, Zhaodong; Chen, Lisha; Bai, Penggang; Lin, Xiang; Pan, Jianji

    2014-01-01

    This study aimed to quantify dosimetric effects of weight loss for nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Overall, 25 patients with NPC treated with IMRT were enrolled. We simulated weight loss during IMRT on the computer. Weight loss model was based on the planning computed tomography (CT) images. The original external contour of head and neck was labeled plan 0, and its volume was regarded as pretreatment normal weight. We shrank the external contour with different margins (2, 3, and 5 mm) and generated new external contours of head and neck. The volumes of reconstructed external contours were regarded as weight during radiotherapy. After recontouring outlines, the initial treatment plan was mapped to the redefined CT scans with the same beam configurations, yielding new plans. The computer model represented a theoretical proportional weight loss of 3.4% to 13.7% during the course of IMRT. The dose delivered to the planning target volume (PTV) of primary gross tumor volume and clinical target volume significantly increased by 1.9% to 2.9% and 1.8% to 2.9% because of weight loss, respectively. The dose to the PTV of gross tumor volume of lymph nodes fluctuated from −2.0% to 1.0%. The dose to the brain stem and the spinal cord was increased (p < 0.001), whereas the dose to the parotid gland was decreased (p < 0.001). Weight loss may lead to significant dosimetric change during IMRT. Repeated scanning and replanning for patients with NPC with an obvious weight loss may be necessary

  10. Will weight loss cause significant dosimetric changes of target volumes and organs at risk in nasopharyngeal carcinoma treated with intensity-modulated radiation therapy?

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Chuanben; Fei, Zhaodong; Chen, Lisha; Bai, Penggang; Lin, Xiang; Pan, Jianji, E-mail: jianjipan@126.com

    2014-04-01

    This study aimed to quantify dosimetric effects of weight loss for nasopharyngeal carcinoma (NPC) treated with intensity-modulated radiation therapy (IMRT). Overall, 25 patients with NPC treated with IMRT were enrolled. We simulated weight loss during IMRT on the computer. Weight loss model was based on the planning computed tomography (CT) images. The original external contour of head and neck was labeled plan 0, and its volume was regarded as pretreatment normal weight. We shrank the external contour with different margins (2, 3, and 5 mm) and generated new external contours of head and neck. The volumes of reconstructed external contours were regarded as weight during radiotherapy. After recontouring outlines, the initial treatment plan was mapped to the redefined CT scans with the same beam configurations, yielding new plans. The computer model represented a theoretical proportional weight loss of 3.4% to 13.7% during the course of IMRT. The dose delivered to the planning target volume (PTV) of primary gross tumor volume and clinical target volume significantly increased by 1.9% to 2.9% and 1.8% to 2.9% because of weight loss, respectively. The dose to the PTV of gross tumor volume of lymph nodes fluctuated from −2.0% to 1.0%. The dose to the brain stem and the spinal cord was increased (p < 0.001), whereas the dose to the parotid gland was decreased (p < 0.001). Weight loss may lead to significant dosimetric change during IMRT. Repeated scanning and replanning for patients with NPC with an obvious weight loss may be necessary.

  11. Dim target detection method based on salient graph fusion

    Science.gov (United States)

    Hu, Ruo-lan; Shen, Yi-yan; Jiang, Jun

    2018-02-01

    Dim target detection is one key problem in digital image processing field. With development of multi-spectrum imaging sensor, it becomes a trend to improve the performance of dim target detection by fusing the information from different spectral images. In this paper, one dim target detection method based on salient graph fusion was proposed. In the method, Gabor filter with multi-direction and contrast filter with multi-scale were combined to construct salient graph from digital image. And then, the maximum salience fusion strategy was designed to fuse the salient graph from different spectral images. Top-hat filter was used to detect dim target from the fusion salient graph. Experimental results show that proposal method improved the probability of target detection and reduced the probability of false alarm on clutter background images.

  12. Planning Target Volume D95 and Mean Dose Should Be Considered for Optimal Local Control for Stereotactic Ablative Radiation Therapy

    Energy Technology Data Exchange (ETDEWEB)

    Zhao, Lina [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Zhou, Shouhao [Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Balter, Peter [Department of Radiation Physics, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Shen, Chan [Department of Health Service Research, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Gomez, Daniel R.; Welsh, James D.; Lin, Steve H. [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Chang, Joe Y., E-mail: jychang@mdanderson.org [Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2016-07-15

    Purpose: To identify the optimal dose parameters predictive for local/lobar control after stereotactic ablative radiation therapy (SABR) in early-stage non-small cell lung cancer (NSCLC). Methods and Materials: This study encompassed a total of 1092 patients (1200 lesions) with NSCLC of clinical stage T1-T2 N0M0 who were treated with SABR of 50 Gy in 4 fractions or 70 Gy in 10 fractions, depending on tumor location/size, using computed tomography-based heterogeneity corrections and a convolution superposition calculation algorithm. Patients were monitored by chest CT or positron emission tomography/CT and/or biopsy after SABR. Factors predicting local/lobar recurrence (LR) were determined by competing risk multivariate analysis. Continuous variables were divided into 2 subgroups at cutoff values identified by receiver operating characteristic curves. Results: At a median follow-up time of 31.7 months (interquartile range, 14.8-51.3 months), the 5-year time to local recurrence within the same lobe and overall survival rates were 93.8% and 44.8%, respectively. Total cumulative number of patients experiencing LR was 40 (3.7%), occurring at a median time of 14.4 months (range, 4.8-46 months). Using multivariate competing risk analysis, independent predictive factors for LR after SABR were minimum biologically effective dose (BED{sub 10}) to 95% of planning target volume (PTVD95 BED{sub 10}) ≤86 Gy (corresponding to PTV D95 physics dose of 42 Gy in 4 fractions or 55 Gy in 10 fractions) and gross tumor volume ≥8.3 cm{sup 3}. The PTVmean BED{sub 10} was highly correlated with PTVD95 BED{sub 10.} In univariate analysis, a cutoff of 130 Gy for PTVmean BED{sub 10} (corresponding to PTVmean physics dose of 55 Gy in 4 fractions or 75 Gy in 10 fractions) was also significantly associated with LR. Conclusions: In addition to gross tumor volume, higher radiation dose delivered to the PTV predicts for better local/lobar control. We recommend that both PTVD95 BED

  13. Deep-Learning-Based Drug-Target Interaction Prediction.

    Science.gov (United States)

    Wen, Ming; Zhang, Zhimin; Niu, Shaoyu; Sha, Haozhi; Yang, Ruihan; Yun, Yonghuan; Lu, Hongmei

    2017-04-07

    Identifying interactions between known drugs and targets is a major challenge in drug repositioning. In silico prediction of drug-target interaction (DTI) can speed up the expensive and time-consuming experimental work by providing the most potent DTIs. In silico prediction of DTI can also provide insights about the potential drug-drug interaction and promote the exploration of drug side effects. Traditionally, the performance of DTI prediction depends heavily on the descriptors used to represent the drugs and the target proteins. In this paper, to accurately predict new DTIs between approved drugs and targets without separating the targets into different classes, we developed a deep-learning-based algorithmic framework named DeepDTIs. It first abstracts representations from raw input descriptors using unsupervised pretraining and then applies known label pairs of interaction to build a classification model. Compared with other methods, it is found that DeepDTIs reaches or outperforms other state-of-the-art methods. The DeepDTIs can be further used to predict whether a new drug targets to some existing targets or whether a new target interacts with some existing drugs.

  14. Pentanol-based target material with polarized protons

    International Nuclear Information System (INIS)

    Bunyatova, E.I.

    1992-01-01

    1-pentanol is a promising material for a target with polarized protons owing to its high resistance to radiation damage. To develop the target, the solutions of 1-pentanol or 2-pentanol with complexes of pentavalent chromium ware investigated. The material based EHBA-Cr(V) solution in a glass-like matrix, consisting of 1-pentanol, 3-pentanol and 1,2-propanediol, was proposed as a target material. It was investigated by the electron paramagnetic resonance and differential scanning calorimetry methods. 24 refs.; 3 figs.; 1 tab

  15. The co registration of initial PET on the CT-radiotherapy reduces significantly the variabilities of anatomo-clinical target volume in the child hodgkin disease

    International Nuclear Information System (INIS)

    Metwally, H.; Blouet, A.; David, I.; Rives, M.; Izar, F.; Courbon, F.; Filleron, T.; Laprie, A.; Plat, G.; Vial, J.

    2009-01-01

    It exists a great interobserver variability for the anatomo-clinical target volume (C.T.V.) definition in children suffering of Hodgkin disease. In this study, the co-registration of the PET with F.D.G. on the planning computed tomography has significantly lead to a greater coherence in the clinical target volume definition. (N.C.)

  16. Automatic definition of targeted biological volumes for the radiotherapy applications; Definition automatique des volumes biologiques cibles pour les applications de radiotherapie

    Energy Technology Data Exchange (ETDEWEB)

    Hatt, M.; Visvikis, D. [LaTIM, U650 Inserm, 29 - Brest (France); Cheze-Le-Rest, C. [Service de medecine nucleaire, 29 - Brest (France); Pradier, O. [Service de radiotherapie, 29 - Brest (France)

    2009-10-15

    The proposed method: Fuzzy locally adaptive Bayesian (F.L.A.B.) showed its reliability and its precision on very complete collection of realistic simulated and real data. Its use in the context of radiotherapy allows to consider easily the studies implementation and scenari of dose painting or dose escalation, including in complex cases of heterogenous fixations. It is conceivable to apply F.L.A.B. on PET images with F.M.I.S.O. ({sup 18}F fluoro misonidazole) or F.L.T. (fluoro-L-thymidine) to complete the definition of the biological target volume. (N.C.)

  17. Human-computer interaction in radiotherapy target volume delineation: a prospective, multi-institutional comparison of user input devices.

    Science.gov (United States)

    2011-10-01

    The purpose of this study was the prospective comparison of objective and subjective effects of target volume region of interest (ROI) delineation using mouse-keyboard and pen-tablet user input devices (UIDs). The study was designed as a prospective test/retest sequence, with Wilcoxon signed rank test for matched-pair comparison. Twenty-one physician-observers contoured target volume ROIs on four standardized cases (representative of brain, prostate, lung, and head and neck malignancies) twice: once using QWERTY keyboard/scroll-wheel mouse UID and once with pen-tablet UID (DTX2100, Wacom Technology Corporation, Vancouver, WA, USA). Active task time, ROI manipulation task data, and subjective survey data were collected. One hundred twenty-nine target volume ROI sets were collected, with 62 paired pen-tablet/mouse-keyboard sessions. Active contouring time was reduced using the pen-tablet UID, with mean ± SD active contouring time of 26 ± 23 min, compared with 32 ± 25 with the mouse (p ≤ 0.01). Subjective estimation of time spent was also reduced from 31 ± 26 with mouse to 27 ± 22 min with the pen (p = 0.02). Task analysis showed ROI correction task reduction (p = 0.045) and decreased panning and scrolling tasks (p < 0.01) with the pen-tablet; drawing, window/level changes, and zoom commands were unchanged (p = n.s.) Volumetric analysis demonstrated no detectable differences in ROI volume nor intra- or inter-observer volumetric coverage. Fifty-two of 62 (84%) users preferred the tablet for each contouring task; 5 of 62 (8%) denoted no preference, and 5 of 62 (8%) chose the mouse interface. The pen-tablet UID reduced active contouring time and reduced correction of ROIs, without substantially altering ROI volume/coverage.

  18. A New Suggestion for the Radiation Target Volume After a Subtotal Gastrectomy in Patients With Stomach Cancer

    International Nuclear Information System (INIS)

    Nam, Heerim; Lim, Do Hoon; Kim, Sung; Kang, Won Ki; Sohn, Tae Sung; Noh, Jae Hyung; Kim, Yong Il; Park, Chan Hyung; Park, Chul Keun; Ahn, Yong Chan; Huh, Seung Jae

    2008-01-01

    Purpose: To compare treatment results between the use of two different radiation fields including and excluding remnant stomach and suggest new target volumes excluding remnant stomach after subtotal gastrectomy (STG) in patients with stomach cancer. Methods and Materials: We retrospectively analyzed 291 patients treated with adjuvant chemoradiotherapy after STG and D2 dissection at the Samsung Medical Center, Seoul, South Korea. Eighty-three patients registered from 1995 to 1997 underwent irradiation according to the INT 0116 protocol that recommended the inclusion of remnant stomach within the target volume (Group A). After this period, we excluded remnant stomach from the target volume for 208 patients (Group B). Median follow-up was 67 months. Results: Treatment failure developed in 93 patients (32.0%). Local and regional recurrence rates for Group A vs. Group B were 10.8% vs. 5.3% (p = not significant) and 9.6% vs. 6.3% (p = not significant), and recurrence rates for remnant stomach were 7.2% vs. 1.4% (p = 0.018), respectively. Overall and disease-free survival rates were not different between the two groups. Grade 3 or 4 vomiting and diarrhea developed more frequently in Group A than Group B (4.8% vs. 1.4% and 6.0% vs. 1.9%, respectively; p = 0.012; p < 0.001). Conclusion: Exclusion of remnant stomach from the radiation field had no effect on failure rates or survival, and a low complication rate occurred in patients treated excluding remnant stomach. We suggest that remnant stomach be excluded from the radiation target volume for patients with stomach cancer who undergo STG and D2 dissection

  19. Suggestion for the prostatic fossa clinical target volume in adjuvant or salvage radiotherapy after a radical prostatectomy

    International Nuclear Information System (INIS)

    Park, Jun Su; Park, Won; Pyo, Hong Ryull; Park, Byung Kwan; Park, Sung Yoon; Choi, Han Yong; Lee, Hyun Moo; Jeon, Seong Soo; Seo, Seong Il; Jeong, Byong Chang; Jeon, Hwang Gyun

    2014-01-01

    Background and purpose: To assess the location of recurrent tumors and suggest the optimal target volume in adjuvant or salvage radiotherapy (RT) after a radical prostatectomy (RP). Material and methods: From January 2000 to December 2012, 113 patients had been diagnosed with suspected recurrent prostate cancer by MRI scan and received salvage RT in the Samsung Medical Center. This study assessed the location of the suspected tumor recurrences and used the inferior border of the pubic symphysis as a point of reference. Results: There were 118 suspect tumor recurrences. The most common site of recurrence was the anastomotic site (78.8%), followed by the bladder neck (15.3%) and retrovesical area (5.9%). In the cranial direction, 106 (87.3%) lesions were located within 30 mm of the reference point. In the caudal direction, 12 lesions (10.2%) were located below the reference point. In the transverse plane, 112 lesions (94.9%) were located within 10 mm of the midline. Conclusions: A MRI scan acquired before salvage RT is useful for the localization of recurrent tumors and the delineation of the target volume. We suggest the optimal target volume in adjuvant or salvage RT after RP, which includes 97% of suspected tumor recurrences

  20. Using injectable hydrogel markers to assess resimulation for boost target volume definition in a patient undergoing whole-breast radiotherapy

    International Nuclear Information System (INIS)

    Patel, Henal; Goyal, Sharad; Kim, Leonard

    2015-01-01

    Several publications have recommended that patients undergoing whole-breast radiotherapy be resimulated for boost planning. The rationale for this is that the seroma may be smaller when compared with the initial simulation. However, the decision remains whether to use the earlier or later images to define an appropriate boost target volume. A patient undergoing whole-breast radiotherapy had new, injectable, temporary hydrogel fiducial markers placed 1 to 3 cm from the seroma at the time of initial simulation. The patient was resimulated 4.5 weeks later for conformal photon boost planning. Computed tomography (CT) scans acquired at the beginning and the end of whole-breast radiotherapy showed that shrinkage of the lumpectomy cavity was not matched by a corresponding reduction in the surrounding tissue volume, as demarcated by hydrogel markers. This observation called into question the usual interpretation of cavity shrinkage for boost target definition. For this patient, it was decided to define the boost target volume on the initial planning CT instead of the new CT.

  1. PRICISE TARGET GEOLOCATION AND TRACKING BASED ON UAV VIDEO IMAGERY

    Directory of Open Access Journals (Sweden)

    H. R. Hosseinpoor

    2016-06-01

    Full Text Available There is an increasingly large number of applications for Unmanned Aerial Vehicles (UAVs from monitoring, mapping and target geolocation. However, most of commercial UAVs are equipped with low-cost navigation sensors such as C/A code GPS and a low-cost IMU on board, allowing a positioning accuracy of 5 to 10 meters. This low accuracy cannot be used in applications that require high precision data on cm-level. This paper presents a precise process for geolocation of ground targets based on thermal video imagery acquired by small UAV equipped with RTK GPS. The geolocation data is filtered using an extended Kalman filter, which provides a smoothed estimate of target location and target velocity. The accurate geo-locating of targets during image acquisition is conducted via traditional photogrammetric bundle adjustment equations using accurate exterior parameters achieved by on board IMU and RTK GPS sensors, Kalman filtering and interior orientation parameters of thermal camera from pre-flight laboratory calibration process. The results of this study compared with code-based ordinary GPS, indicate that RTK observation with proposed method shows more than 10 times improvement of accuracy in target geolocation.

  2. Target Detection Based on EBPSK Satellite Passive Radar

    Directory of Open Access Journals (Sweden)

    Lu Zeyuan

    2015-05-01

    Full Text Available Passive radar is a topic anti stealth technology with simple structure, and low cost. Radiation source model, signal transmission model, and target detection are the key points of passive radar technology research. The paper analyzes the characteristics of EBPSK signal modulation and target detection method aspect of spaceborne radiant source. By comparison with other satellite navigation and positioning system, the characteristics of EBPSK satellite passive radar system are analyzed. It is proved that the maximum detection range of EBPSK satellite signal can satisfy the needs of the proposed model. In the passive radar model, sparse representation is used to achieve high resolution DOA detection. The comparison with the real target track by simulation demonstrates that effective detection of airborne target using EBPSK satellite passive radar system based on sparse representation is efficient.

  3. Infrared small target enhancement based on variance difference

    Science.gov (United States)

    Nasiri, Mahdi; Chehresa, Saeed

    2017-05-01

    In surveillance and early warning systems, the enhancement of targets is a very important stage for the high reliability detection and tracking in Infrared images with complex backgrounds. In order to enhance small targets in an Infrared image and suppress the background clutter, consequently increasing the contrast between them, this paper proposes a method using a model for the target area with a three-layer patch-image model and based on the difference between the variance of the layers in the neighboring areas of the investigated pixel. Results of the experiments indicate that the proposed method is quite effective on the enhancement of small targets as well as suppression of the background clutter in IR images with a minimum false alarm rate. This is realized while the runtime of the proposed method is minimal compared to other commonly used methods, which makes it effective to be used in real time applications.

  4. SU-F-J-115: Target Volume and Artifact Evaluation of a New Device-Less 4D CT Algorithm

    Energy Technology Data Exchange (ETDEWEB)

    Martin, R; Pan, T [UT MD Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: 4DCT is often used in radiation therapy treatment planning to define the extent of motion of the visible tumor (IGTV). Recent available software allows 4DCT images to be created without the use of an external motion surrogate. This study aims to compare this device-less algorithm to a standard device-driven technique (RPM) in regards to artifacts and the creation of treatment volumes. Methods: 34 lung cancer patients who had previously received a cine 4DCT scan on a GE scanner with an RPM determined respiratory signal were selected. Cine images were sorted into 10 phases based on both the RPM signal and the device-less algorithm. Contours were created on standard and device-less maximum intensity projection (MIP) images using a region growing algorithm and manual adjustment to remove other structures. Variations in measurements due to intra-observer differences in contouring were assessed by repeating a subset of 6 patients 2 additional times. Artifacts in each phase image were assessed using normalized cross correlation at each bed position transition. A score between +1 (artifacts “better” in all phases for device-less) and −1 (RPM similarly better) was assigned for each patient based on these results. Results: Device-less IGTV contours were 2.1 ± 1.0% smaller than standard IGTV contours (not significant, p = 0.15). The Dice similarity coefficient (DSC) was 0.950 ± 0.006 indicating good similarity between the contours. Intra-observer variation resulted in standard deviations of 1.2 percentage points in percent volume difference and 0.005 in DSC measurements. Only two patients had improved artifacts with RPM, and the average artifact score (0.40) was significantly greater than zero. Conclusion: Device-less 4DCT can be used in place of the standard method for target definition due to no observed difference between standard and device-less IGTVs. Phase image artifacts were significantly reduced with the device-less method.

  5. Comparison of Magnetic Resonance Imaging and Computed Tomography for Breast Target Volume Delineation in Prone and Supine Positions

    Energy Technology Data Exchange (ETDEWEB)

    Pogson, Elise M. [Centre for Medical Radiation Physics, Faculty of Engineering and Information Sciences, University of Wollongong, Wollongong (Australia); Liverpool and Macarthur Cancer Therapy Centres, Liverpool (Australia); Ingham Institute for Applied Medical Research, Liverpool (Australia); Delaney, Geoff P. [Liverpool and Macarthur Cancer Therapy Centres, Liverpool (Australia); Ingham Institute for Applied Medical Research, Liverpool (Australia); South Western Sydney Clinical School, University of New South Wales, Sydney (Australia); School of Medicine, University of Western Sydney, Sydney (Australia); Ahern, Verity [Crown Princess Mary Cancer Care Centre, Westmead Hospital, Westmead (Australia); Boxer, Miriam M. [Liverpool and Macarthur Cancer Therapy Centres, Liverpool (Australia); South Western Sydney Clinical School, University of New South Wales, Sydney (Australia); Chan, Christine [Department of Radiology, Liverpool Hospital, Liverpool (Australia); David, Steven [Peter MacCallum Cancer Centre, Melbourne (Australia); Dimigen, Marion [Department of Radiology, Liverpool Hospital, Liverpool (Australia); Harvey, Jennifer A. [School of Medicine, University of Queensland, Herston (Australia); Princess Alexandra Hospital, Woolloongabba (Australia); Koh, Eng-Siew [Liverpool and Macarthur Cancer Therapy Centres, Liverpool (Australia); Ingham Institute for Applied Medical Research, Liverpool (Australia); South Western Sydney Clinical School, University of New South Wales, Sydney (Australia); Lim, Karen [Liverpool and Macarthur Cancer Therapy Centres, Liverpool (Australia); South Western Sydney Clinical School, University of New South Wales, Sydney (Australia); Papadatos, George [Liverpool and Macarthur Cancer Therapy Centres, Liverpool (Australia); and others

    2016-11-15

    Purpose: To determine whether T2-weighted MRI improves seroma cavity (SC) and whole breast (WB) interobserver conformity for radiation therapy purposes, compared with the gold standard of CT, both in the prone and supine positions. Methods and Materials: Eleven observers (2 radiologists and 9 radiation oncologists) delineated SC and WB clinical target volumes (CTVs) on T2-weighted MRI and CT supine and prone scans (4 scans per patient) for 33 patient datasets. Individual observer's volumes were compared using the Dice similarity coefficient, volume overlap index, center of mass shift, and Hausdorff distances. An average cavity visualization score was also determined. Results: Imaging modality did not affect interobserver variation for WB CTVs. Prone WB CTVs were larger in volume and more conformal than supine CTVs (on both MRI and CT). Seroma cavity volumes were larger on CT than on MRI. Seroma cavity volumes proved to be comparable in interobserver conformity in both modalities (volume overlap index of 0.57 (95% Confidence Interval (CI) 0.54-0.60) for CT supine and 0.52 (95% CI 0.48-0.56) for MRI supine, 0.56 (95% CI 0.53-0.59) for CT prone and 0.55 (95% CI 0.51-0.59) for MRI prone); however, after registering modalities together the intermodality variation (Dice similarity coefficient of 0.41 (95% CI 0.36-0.46) for supine and 0.38 (0.34-0.42) for prone) was larger than the interobserver variability for SC, despite the location typically remaining constant. Conclusions: Magnetic resonance imaging interobserver variation was comparable to CT for the WB CTV and SC delineation, in both prone and supine positions. Although the cavity visualization score and interobserver concordance was not significantly higher for MRI than for CT, the SCs were smaller on MRI, potentially owing to clearer SC definition, especially on T2-weighted MR images.

  6. Human MAP Tau Based Targeted Cytolytic Fusion Proteins

    Directory of Open Access Journals (Sweden)

    Olusiji A. Akinrinmade

    2017-06-01

    Full Text Available Some of the most promising small molecule toxins used to generate antibody drug conjugates (ADCs include anti-mitotic agents (e.g., auristatin and its derivatives which are designed to attack cancerous cells at their most vulnerable state during mitosis. We were interested in identifying a human cystostatic protein eventually showing comparable activities and allowing the generation of corresponding targeted fully human cytolytic fusion proteins. Recently, we identified the human microtubule associated protein tau (MAP tau, which binds specifically to tubulin and modulates the stability of microtubules, thereby blocking mitosis and presumably vesicular transport. By binding and stabilizing polymerized microtubule filaments, MAP tau-based fusion proteins skew microtubule dynamics towards cell cycle arrest and apoptosis. This biological activity makes rapidly proliferating cells (e.g., cancer and inflammatory cells an excellent target for MAP tau-based targeted treatments. Their superior selectivity for proliferating cells confers additional selectivity towards upregulated tumor-associated antigens at their surface, thereby preventing off-target related toxicity against normal cells bearing tumor-associated antigens at physiologically normal to low levels. In this review, we highlight recent findings on MAP tau-based targeted cytolytic fusion proteins reported in preclinical immunotherapeutic studies.

  7. Drug-target interaction prediction from PSSM based evolutionary information.

    Science.gov (United States)

    Mousavian, Zaynab; Khakabimamaghani, Sahand; Kavousi, Kaveh; Masoudi-Nejad, Ali

    2016-01-01

    The labor-intensive and expensive experimental process of drug-target interaction prediction has motivated many researchers to focus on in silico prediction, which leads to the helpful information in supporting the experimental interaction data. Therefore, they have proposed several computational approaches for discovering new drug-target interactions. Several learning-based methods have been increasingly developed which can be categorized into two main groups: similarity-based and feature-based. In this paper, we firstly use the bi-gram features extracted from the Position Specific Scoring Matrix (PSSM) of proteins in predicting drug-target interactions. Our results demonstrate the high-confidence prediction ability of the Bigram-PSSM model in terms of several performance indicators specifically for enzymes and ion channels. Moreover, we investigate the impact of negative selection strategy on the performance of the prediction, which is not widely taken into account in the other relevant studies. This is important, as the number of non-interacting drug-target pairs are usually extremely large in comparison with the number of interacting ones in existing drug-target interaction data. An interesting observation is that different levels of performance reduction have been attained for four datasets when we change the sampling method from the random sampling to the balanced sampling. Copyright © 2015 Elsevier Inc. All rights reserved.

  8. Performance of Leak Compensation in All-Age ICU Ventilators During Volume-Targeted Neonatal Ventilation: A Lung Model Study.

    Science.gov (United States)

    Itagaki, Taiga; Bennett, Desmond J; Chenelle, Christopher T; Fisher, Daniel F; Kacmarek, Robert M

    2017-01-01

    Volume-targeted ventilation is increasingly used in low birthweight infants because of the potential for reducing volutrauma and avoiding hypocapnea. However, it is not known what level of air leak is acceptable during neonatal volume-targeted ventilation when leak compensation is activated concurrently. Four ICU ventilators (Servo-i, PB980, V500, and Avea) were compared in available invasive volume-targeted ventilation modes (pressure control continuous spontaneous ventilation [PC-CSV] and pressure control continuous mandatory ventilation [PC-CMV]). The Servo-i and PB980 were tested with (+) and without (-) their proximal flow sensor. The V500 and Avea were tested with their proximal flow sensor as indicated by their manufacturers. An ASL 5000 lung model was used to simulate 4 neonatal scenarios (body weight 0.5, 1, 2, and 4 kg). The ASL 5000 was ventilated via an endotracheal tube with 3 different leaks. Two minutes of data were collected after each change in leak level, and the asynchrony index was calculated. Tidal volume (V T ) before and after the change in leak was assessed. The differences in delivered V T between before and after the change in leak were within ±5% in all scenarios with the PB980 (-/+) and V500. With the Servo-i (-/+), baseline V T was ≥10% greater than set V T during PC-CSV, and delivered V T markedly changed with leak. The Avea demonstrated persistent high V T in all leak scenarios. Across all ventilators, the median asynchrony index was 1% (interquartile range 0-27%) in PC-CSV and 1.8% (0-45%) in PC-CMV. The median asynchrony index was significantly higher in the Servo-i (-/+) than in the PB980 (-/+) and V500 in 1 and 2 kg scenarios during PC-CSV and PC-CMV. The PB980 and V500 were the only ventilators to acclimate to all leak scenarios and achieve targeted V T . Further clinical investigation is needed to validate the use of leak compensation during neonatal volume-targeted ventilation. Copyright © 2017 by Daedalus Enterprises.

  9. Sparing Healthy Tissue and Increasing Tumor Dose Using Bayesian Modeling of Geometric Uncertainties for Planning Target Volume Personalization

    Energy Technology Data Exchange (ETDEWEB)

    Herschtal, Alan, E-mail: Alan.Herschtal@petermac.org [Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne (Australia); Faculty of Health, Arts and Design, Swinburne University of Technology, Melbourne (Australia); Te Marvelde, Luc [Department of Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, Melbourne (Australia); Mengersen, Kerrie [School of Mathematical Sciences, Science and Engineering Faculty, Queensland University of Technology, Brisbane (Australia); Foroudi, Farshad [Department of Radiation Oncology, Peter MacCallum Cancer Centre, Melbourne (Australia); The Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne (Australia); Eade, Thomas [Northern Sydney Cancer Centre, Radiation Oncology Department, Royal North Shore Hospital, St. Leonards, Sydney (Australia); Northern Clinical School, University of Sydney (Australia); Pham, Daniel [Department of Radiation Therapy, Peter MacCallum Cancer Centre, Melbourne (Australia); Caine, Hannah [Northern Sydney Cancer Centre, Radiation Oncology Department, Royal North Shore Hospital, St. Leonards, Sydney (Australia); Kron, Tomas [The Sir Peter MacCallum Department of Oncology, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne (Australia); Department of Physical Sciences, Peter MacCallum Cancer Centre, Melbourne (Australia)

    2015-06-01

    Objective: To develop a mathematical tool that can update a patient's planning target volume (PTV) partway through a course of radiation therapy to more precisely target the tumor for the remainder of treatment and reduce dose to surrounding healthy tissue. Methods and Materials: Daily on-board imaging was used to collect large datasets of displacements for patients undergoing external beam radiation therapy for solid tumors. Bayesian statistical modeling of these geometric uncertainties was used to optimally trade off between displacement data collected from previously treated patients and the progressively accumulating data from a patient currently partway through treatment, to optimally predict future displacements for that patient. These predictions were used to update the PTV position and margin width for the remainder of treatment, such that the clinical target volume (CTV) was more precisely targeted. Results: Software simulation of dose to CTV and normal tissue for 2 real prostate displacement datasets consisting of 146 and 290 patients treated with a minimum of 30 fractions each showed that re-evaluating the PTV position and margin width after 8 treatment fractions reduced healthy tissue dose by 19% and 17%, respectively, while maintaining CTV dose. Conclusion: Incorporating patient-specific displacement patterns from early in a course of treatment allows PTV adaptation for the remainder of treatment. This substantially reduces the dose to healthy tissues and thus can reduce radiation therapy–induced toxicities, improving patient outcomes.

  10. External Validation and Optimization of International Consensus Clinical Target Volumes for Adjuvant Radiation Therapy in Bladder Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Abhinav V. [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Christodouleas, John P. [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, Pennsylvania (United States); Wu, Tianming [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Smith, Norman D.; Steinberg, Gary D. [Section of Urology, Department of Surgery, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States); Liauw, Stanley L., E-mail: sliauw@radonc.uchicago.edu [Department of Radiation and Cellular Oncology, University of Chicago Pritzker School of Medicine, Chicago, Illinois (United States)

    2017-03-15

    Purpose: International consensus (IC) clinical target volumes (CTVs) have been proposed to standardize radiation field design in the treatment of patients at high risk of locoregional failure (LRF) after radical cystectomy. The purpose of this study was to externally validate the IC CTVs in a cohort of postsurgical patients followed up for LRF and identify revisions that might improve the IC CTVs' performance. Methods and Materials: Among 334 patients with pT3 to pT4 bladder cancer treated with radical cystectomy, LRF developed in 58 (17%), of whom 52 had computed tomography scans available for review. Images with LRF were exported into a treatment planning system, and IC CTVs were contoured and evaluated for adequacy of coverage of each LRF with respect to both the patient and each of 6 pelvic subsites: common iliac (CI) region, obturator region (OR), external and internal iliac region, presacral region, cystectomy bed, or other pelvic site. Revisions to the IC contours were proposed based on the findings. Results: Of the 52 patients with documented LRF, 13 (25%) had LRFs that were outside of the IC CTV involving 17 pelvic subsites: 5 near the CI CTV, 5 near the OR CTV, 1 near the external and internal iliac region, and 6 near the cystectomy bed. The 5 CI failures were located superior to the CTV, and the 5 OR failures were located medial to the CTV. Increasing the superior boundary of the CI to a vessel-based definition of the aortic bifurcation, as well as increasing the medial extension of the OR by an additional 9 mm, decreased the number of patients with LRF outside of the IC CTV to 7 (13%). Conclusions: Modified IC CTVs inclusive of a slight adjustment superiorly for the CI region and medially for the OR may reduce the risk of pelvic failure in patients treated with adjuvant radiation therapy.

  11. Artificial Neural Network-Based System for PET Volume Segmentation

    Directory of Open Access Journals (Sweden)

    Mhd Saeed Sharif

    2010-01-01

    Full Text Available Tumour detection, classification, and quantification in positron emission tomography (PET imaging at early stage of disease are important issues for clinical diagnosis, assessment of response to treatment, and radiotherapy planning. Many techniques have been proposed for segmenting medical imaging data; however, some of the approaches have poor performance, large inaccuracy, and require substantial computation time for analysing large medical volumes. Artificial intelligence (AI approaches can provide improved accuracy and save decent amount of time. Artificial neural networks (ANNs, as one of the best AI techniques, have the capability to classify and quantify precisely lesions and model the clinical evaluation for a specific problem. This paper presents a novel application of ANNs in the wavelet domain for PET volume segmentation. ANN performance evaluation using different training algorithms in both spatial and wavelet domains with a different number of neurons in the hidden layer is also presented. The best number of neurons in the hidden layer is determined according to the experimental results, which is also stated Levenberg-Marquardt backpropagation training algorithm as the best training approach for the proposed application. The proposed intelligent system results are compared with those obtained using conventional techniques including thresholding and clustering based approaches. Experimental and Monte Carlo simulated PET phantom data sets and clinical PET volumes of nonsmall cell lung cancer patients were utilised to validate the proposed algorithm which has demonstrated promising results.

  12. Artificial Neural Network-Based System for PET Volume Segmentation.

    Science.gov (United States)

    Sharif, Mhd Saeed; Abbod, Maysam; Amira, Abbes; Zaidi, Habib

    2010-01-01

    Tumour detection, classification, and quantification in positron emission tomography (PET) imaging at early stage of disease are important issues for clinical diagnosis, assessment of response to treatment, and radiotherapy planning. Many techniques have been proposed for segmenting medical imaging data; however, some of the approaches have poor performance, large inaccuracy, and require substantial computation time for analysing large medical volumes. Artificial intelligence (AI) approaches can provide improved accuracy and save decent amount of time. Artificial neural networks (ANNs), as one of the best AI techniques, have the capability to classify and quantify precisely lesions and model the clinical evaluation for a specific problem. This paper presents a novel application of ANNs in the wavelet domain for PET volume segmentation. ANN performance evaluation using different training algorithms in both spatial and wavelet domains with a different number of neurons in the hidden layer is also presented. The best number of neurons in the hidden layer is determined according to the experimental results, which is also stated Levenberg-Marquardt backpropagation training algorithm as the best training approach for the proposed application. The proposed intelligent system results are compared with those obtained using conventional techniques including thresholding and clustering based approaches. Experimental and Monte Carlo simulated PET phantom data sets and clinical PET volumes of nonsmall cell lung cancer patients were utilised to validate the proposed algorithm which has demonstrated promising results.

  13. Volume-based Interval Training Program for Elite Tennis Players.

    Science.gov (United States)

    Myers, Natalie L; Sciascia, Aaron D; Kibler, W Ben; Uhl, Tim L

    A sport-specific conditioning program can help tennis players train for competition or return to play from injury. This study determined the actual tennis serve volume in elite play and used these data to construct an interval training program based on stroke volume. There will be no differences in serve volume between male and female tennis players at the professional and junior levels. Retrospective cohort study. Level 3. Game day statistic scorecards were provided to the research team from the 2013 and 2014 United States Open and the 2014 Metropolia Orange Bowl International Tennis Championships. Serve volume data for both male and female players were extracted from the scorecards. Data included serves per match and per set. These data were used to construct a sport-specific tennis program to meet the demands of the serve. Professional male players serve 63 more serves per match than junior male players because of the greater number of sets played ( P < 0.01). Professional female players serve 10 more serves per match than junior female players playing the same number of sets ( P = 0.01). All male players hit 2 more total serves per set than all female players ( P < 0.01). Regardless of sex, professional players serve 4 more serves per set than junior players ( P < 0.01). The typical number of serves per set was 40 in elite-level tennis players, resulting in a 3:1 ratio of first to second serves. These data establish the "unit dose" of serves per match and/or per set for each group. Coaches and health care providers may use these data in estimating loads per tournament/season and to prepare tennis athletes for individual competition and/or as they return to play after an injury.

  14. Classification and Target Group Selection Based Upon Frequent Patterns

    NARCIS (Netherlands)

    W.H.L.M. Pijls (Wim); R. Potharst (Rob)

    2000-01-01

    textabstractIn this technical report , two new algorithms based upon frequent patterns are proposed. One algorithm is a classification method. The other one is an algorithm for target group selection. In both algorithms, first of all, the collection of frequent patterns in the training set is

  15. Clinical investigations on the use of positron emission tomography (PET) for target volume definition in radiation therapy planning; Klinische Untersuchungen zum Einsatz der Positronen-Emissions-Tomographie (PET) in der Zielvolumendefinition bei der Bestrahlungsplanung

    Energy Technology Data Exchange (ETDEWEB)

    Steffen, Ingo G.

    2014-12-05

    The aim of the present study was to evaluate the clinical value of positron emission tomography (PET) for target volume definition in different tumor entities using different tracers and taking pretreatment of patients into account. The study collective comprised 109 patients with 112 target volumes. In 48 patients with skull base meningiomas (SBM) and 42 patients with meningiomas of other localizations (SOM) undergoing fractionated stereotactic radiation therapy the gross tumor volumes (SBM, n=48; SOM, n=39) based on magnetic resonance imaging/computed tomography (MRI/CT) and {sup 68}Ga-DOTATOC-PET were compared retrospectively. Additionally, in 19 patients with liver metastasis from colorectal cancer (LM-CRC) treated in 25 CT guided brachytherapy sessions the clinical target volumes (CTV) either based on MRI/CT or {sup 18}F-FDG-PET were compared retrospectively. The spatial agreement of the target volumes was analyzed using the Dice similarity coefficient (DSC). The association of DSC, tumor entity and pretreatment was analyzed using the general linear model (GLM). Metric parameters are given as median (25th/75th-quartile). In the complete patient sample the PET based target volume was 24.1 (10.8/51.2) ml and, thus, significantly (p<0.001) increased by 18.9% (-3.6%/62.7%) compared to the MRI/CT based target volume of 20.8 (8.6/45.0) ml. In the subgroup of LM-CRC, the PET based target volume was significantly increased by 24.4% (0%/ 71.4%; p=0.021), and in patients with SBM it was increased by 23.9%(-1.7%/65.7%; p=0.003) whereas in SOM the difference of 8.0% (-3.6%/51.7%; p=0.199) was not significant. The DSC for PET and MRI/CT based target volumes was 0.66 (0.46/0.76) in the whole study group and varied between 0.65 (0.46/0.71) in patients with SBM and 0.70 (0.40/0.79) in patients with SOM. In pre-treated patients with LM-CRC a significant lower DSC of 0.62 (0.41/0.66) was observed in comparison to 0.84 (0.70/0.96) in untreated patients (significant interaction

  16. Ground-based observations of Kepler asteroseismic targets

    DEFF Research Database (Denmark)

    Uyttterhoeven , K.; Karoff, Christoffer

    2010-01-01

    We present the ground-based activities within the different working groups of the Kepler Asteroseismic Science Consortium (KASC). The activities aim at the systematic characterization of the 5000+ KASC targets, and at the collection of ground-based follow-up time-series data of selected promising...... Kepler pulsators. So far, 36 different instruments at 31 telescopes on 23 different observatories in 12 countries are in use, and a total of more than 530 observing nights has been awarded....

  17. A dose-volume-based tool for evaluating and ranking IMRT treatment plans.

    Science.gov (United States)

    Miften, Moyed M; Das, Shiva K; Su, Min; Marks, Lawrence B

    2004-01-01

    External beam radiotherapy is commonly used for patients with cancer. While tumor shrinkage and palliation are frequently achieved, local control and cure remain elusive for many cancers. With regard to local control, the fundamental problem is that radiotherapy-induced normal tissue injury limits the dose that can be delivered to the tumor. While intensity-modulated radiation therapy (IMRT) allows for the delivery of higher tumor doses and the sparing of proximal critical structures, multiple competing plans can be generated based on dosimetric and/or biological constraints that need to be considered/compared. In this work, an IMRT treatment plan evaluation and ranking tool, based on dosimetric criteria, is presented. The treatment plan with the highest uncomplicated target conformity index (TCI+) is ranked at the top. The TCI+ is a dose-volume-based index that considers both a target conformity index (TCI) and a normal tissue-sparing index (NTSI). TCI+ is designed to assist in the process of judging the merit of a clinical treatment plan. To demonstrate the utility of this tool, several competing lung and prostate IMRT treatment plans are compared. Results show that the plan with the highest TCI+ values accomplished the competing goals of tumor coverage and critical structures sparing best, among rival treatment plans for both treatment sites. The study demonstrates, first, that dose-volume-based indices, which summarize complex dose distributions through a single index, can be used to automatically select the optimal plan among competing plans, and second, that this dose-volume-based index may be appropriate for ranking IMRT dose distributions.

  18. SU-E-T-170: Characterization of the Location, Extent, and Proximity to Critical Structures of Target Volumes Provides Detail for Improved Outcome Predictions Among Pancreatic Cancer Patients

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Z; Moore, J; Rosati, L; Mian, O; Narang, A; Herman, J; McNutt, T [Johns Hopkins University, Baltimore, MD (United States)

    2015-06-15

    Purpose: In radiotherapy, size, location and proximity of the target to critical structures influence treatment decisions. It has been shown that proximity of the target predicts dosimetric sparing of critical structures. In addition to dosimetry, precise location of disease has further implications such as tumor invasion, or proximity to major arteries that inhibit surgery. Knowledge of which patients can be converted to surgical candidates by radiation may have high impact on future treat/no-treat decisions. We propose a method to improve our characterization of the location of pancreatic cancer and treatment volume extent with respect to nearby arteries with the goal of developing features to improve clinical predictions and decisions. Methods: Oncospace is a local learning health system that systematically captures clinical outcomes and all aspects of radiotherapy treatment plans, including overlap volume histograms (OVH) – a measure of spatial relationships between two structures. Minimum and maximum distances of PTV and OARs based on OVH, PTV volume, anatomic location by ICD-9 code, and surgical outcome were queried. Normalized distance to center from the left and right kidney was calculated to indicate tumor location and laterality. Distance to critical arteries (celiac, superior mesenteric, common hepatic) is validated by surgical status (borderline resectable, locally advanced converted to resectable). Results: There were 205 pancreas stereotactic body radiotherapy patients treated from 2009–2015 queried. Location/laterality of tumor based on kidney OVH show strong trends between location by OVH and by ICD-9. Compared to the locally advanced group, the borderline resectable group showed larger geometrical distance from critical arteries (p=0.03). Conclusion: Our platform enabled analysis of shape/size-location relationships. These data suggest that PTV volume and attention to distance between PTVs and surrounding OARs and major arteries may be

  19. SU-E-T-170: Characterization of the Location, Extent, and Proximity to Critical Structures of Target Volumes Provides Detail for Improved Outcome Predictions Among Pancreatic Cancer Patients

    International Nuclear Information System (INIS)

    Cheng, Z; Moore, J; Rosati, L; Mian, O; Narang, A; Herman, J; McNutt, T

    2015-01-01

    Purpose: In radiotherapy, size, location and proximity of the target to critical structures influence treatment decisions. It has been shown that proximity of the target predicts dosimetric sparing of critical structures. In addition to dosimetry, precise location of disease has further implications such as tumor invasion, or proximity to major arteries that inhibit surgery. Knowledge of which patients can be converted to surgical candidates by radiation may have high impact on future treat/no-treat decisions. We propose a method to improve our characterization of the location of pancreatic cancer and treatment volume extent with respect to nearby arteries with the goal of developing features to improve clinical predictions and decisions. Methods: Oncospace is a local learning health system that systematically captures clinical outcomes and all aspects of radiotherapy treatment plans, including overlap volume histograms (OVH) – a measure of spatial relationships between two structures. Minimum and maximum distances of PTV and OARs based on OVH, PTV volume, anatomic location by ICD-9 code, and surgical outcome were queried. Normalized distance to center from the left and right kidney was calculated to indicate tumor location and laterality. Distance to critical arteries (celiac, superior mesenteric, common hepatic) is validated by surgical status (borderline resectable, locally advanced converted to resectable). Results: There were 205 pancreas stereotactic body radiotherapy patients treated from 2009–2015 queried. Location/laterality of tumor based on kidney OVH show strong trends between location by OVH and by ICD-9. Compared to the locally advanced group, the borderline resectable group showed larger geometrical distance from critical arteries (p=0.03). Conclusion: Our platform enabled analysis of shape/size-location relationships. These data suggest that PTV volume and attention to distance between PTVs and surrounding OARs and major arteries may be

  20. Sollims Sampler: Targeting Peace and Stability Operations Lessons and Best Practices. Volume 2, Issue 1

    Science.gov (United States)

    2011-01-01

    Biddle, Fotini Christia , and F. Alexander Thier in Foreign Affairs, July/August 2010, volume 89, number 4. This article is available at http...www.foreignaffairs.com/articles/66450/stephen-biddle-fotini- christia -and- j-alexander-thier/defining-success-in-afghanistan A second related article

  1. Acceptability of Service Targets for ICT-Based Healthcare.

    Science.gov (United States)

    Jeon, Eun Min; Seo, Hwa Jeong

    2016-10-01

    In order to adopt and activate telemedicine it is necessary to survey how medical staff, who are providers of medical service, and consumers, who are the service targets, perceive information and communication technology (ICT)-based healthcare service. This study surveyed the awareness and acceptability of ICT-based healthcare by involving service targets, specifically workers and students living in the Seoul and Gyeonggi regions who are consumers of healthcare service. To determine the correlation among awareness of ICT-based healthcare, the need for self-management, and acceptability, this study conducted a correlation analysis and a simple regression analysis. According to the responses to the questions on the need for ICT-based healthcare service by item, blood pressure (n = 279, 94.3%) and glucose (n = 277, 93.6%) were revealed to be the physiological signal monitoring area. Among the six measurement factors affecting ICT-based healthcare service acceptability, age, health concerns, and effect expectation had the most significant effects. As effect expectation increased, acceptability became 4.38 times higher ( p ICT-based healthcare service. The fact that acceptability is higher among people who have family disease history or greater health concerns may lead to service targets' more active participation. This study also confirmed that a policy to motivate active participation of those in their 40s (who had high prevalence rates) was needed.

  2. The planning target volume margins detected by cone-beam CT in head and neck cancer patients treated by image-guided intensity modulated radiotherapy

    International Nuclear Information System (INIS)

    Liu Jun; Chen Hong; Zhang Guoqiao; Chen Fei; Zhang Li

    2011-01-01

    Objective: To determine the planning target volume margins of head and neck cancers treated by image guided radiotherapy (IGRT). Methods: 464 sets cone beam computed tomography (CBCT) images before setup correction and 126 sets CBCT images after correction were obtained from 51 head and neck cancer patients treated by IGRT in our department. The systematic and random errors were evaluated by either online or offline correction through registering the CBCT images to the planning CT. The data was divided into 3 groups according to the online correction times. Results: The isocenter shift were 0.37 mm ± 2.37 mm, -0.43 mm ± 2.30 mm and 0.47 mm ± 2.65 mm in right-left (RL), anterior-posterior (AP) and superior-inferior (SI) directions respectively before correction, and it reduced to 0.08 mm ± 0.68 mm, -0.03 mm ± 0.74 mm and 0.03 mm ± 0.80 mm when evaluated by 126 sets corrected CBCT images. The planning target volume (PTV) margin from clinical target volume (CTV) before correction were: 6.41 mm, 6.15 mm and 7.10 mm based on two parameter model, and it reduced to 1.78 mm, 1.80 mm and 1.97 mm after correction. The PTV margins were 3.8 mm, 3.8 mm, 4.0 mm; 4.0 mm, 4.0 mm, 5.0 mm and 5.4 mm, 5.2 mm, 6.1 mm in RL, AP and SI respectively when online-correction times were more than 15 times, 11-15 times, 5-10 times. Conclusions: CBCT-based on online correction reduce the PTV margin for head and neck cancers treated by IGRT and ensure more precise dose delivery and less normal tissue complications. (authors)

  3. ANALISIS SEGMENTASI, TARGETING, POSITIONING (STP TERHADAP PENINGKATAN VOLUME PENJUALAN PADA RUMAH GRIYA MULYA ASRI DI KOTA MAKASSAR

    Directory of Open Access Journals (Sweden)

    Fitri _

    2017-08-01

    Full Text Available Volume at Griya Mulya Asri House In Makassar City. Guided by DR.Hj.Herminawati Abubakar., S.E., M.M and DR.Haeruddin Saleh., S.E., M.SiHome is a basic human need other than clothing and food. The increasing housing demand for Makassar residents encourages housing developers to provide more viable alternative housing solutions. Griya Mulya Asri Housing Estate is one of the best alternative choice for people who want a relaxed atmosphere amidst the urban bustle. Griya Mulya Asri Housing is very good for the habitable area in terms of price, facilities, comfort and location.This study aims to analyze the strategy of segmentation, targeting, positioning (STP applied by PT Hinda Assalam Brother to increase the sales volume of the house at Griya Mulya Asri. Analyzer used is multiple linear regression. Respondents of this research are Griya Mulya Asri resident. The result of analysis shows that segmentation, targeting, positioning strategy influence to the increase of sales volume.

  4. Mapping Patterns of Ipsilateral Supraclavicular Nodal Metastases in Breast Cancer: Rethinking the Clinical Target Volume for High-risk Patients

    Energy Technology Data Exchange (ETDEWEB)

    Jing, Hao [Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Wang, Shu-Lian, E-mail: wsl20040118@yahoo.com [Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Li, Jing; Xue, Mei; Xiong, Zu-Kun [Department of Radiology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Jin, Jing; Wang, Wei-Hu; Song, Yong-Wen; Liu, Yue-Ping; Ren, Hua; Fang, Hui; Yu, Zi-Hao; Liu, Xin-Fan [Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China); Li, Ye-Xiong, E-mail: yexiong12@163.com [Department of Radiation Oncology, Cancer Hospital and Institute, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing (China)

    2015-10-01

    Purpose: To map the location of metastatic supraclavicular (SCV) lymph nodes (LNMs) in breast cancer patients with SCV node involvement and determine whether and where the radiation therapy clinical target volume (CTV) of this region could be modified in high-risk subsets. Methods and Materials: Fifty-five patients with metastatic SCV LNMs were eligible for geographic mapping and atlas coverage analysis. All LNMs and their epicenters were registered proportionally by referencing the surrounding landmarks onto simulation computed tomography images of a standard patient. CTVs based on selected SCV atlases, including the one by the Radiation Therapy Oncology Group (RTOG) were contoured. A modified SCV CTV was tried and shown to have better involved-node coverage and thus theoretically improved prophylaxis in this setting. Results: A total of 50 (91%) and 45 (81.8%) patients had LNMs in the medial and lateral SCV subregions, respectively. Also, 36 patients (65.5%) had LNMs located at the junction of the jugular-subclavian veins. All nodes were covered in only 25.5% to 41.8% of patients by different atlases. The RTOG atlas covered all nodes in 25.5% of patients. Stratified by the nodes in all the patients as a whole, 49.2% to 81.3% were covered, and the RTOG atlas covered 62.6%. The lateral and posterior borders were the most overlooked locations. Modification by extending the borders to natural anatomic barriers allowed the new CTV to cover all the nodes in 81.8% of patients and encompass 96.1% of all the nodes. Conclusions: According to the distribution of SCV LNMs, the extent of existing atlases might not be adequate for potential metastatic sites in certain groups of patients. The extension of the lateral and posterior CTV borders in high-risk or recurrent patients might be a reasonable approach for increasing coverage. However, additional data in more homogeneous populations with localized disease are needed before routine application.

  5. Radionuclide-Based Cancer Imaging Targeting the Carcinoembryonic Antigen

    Directory of Open Access Journals (Sweden)

    Hao Hong

    2008-01-01

    Full Text Available Carcinoembryonic antigen (CEA, highly expressed in many cancer types, is an important target for cancer diagnosis and therapy. Radionuclide-based imaging techniques (gamma camera, single photon emission computed tomography [SPECT] and positron emission tomography [PET] have been extensively explored for CEA-targeted cancer imaging both preclinically and clinically. Briefly, these studies can be divided into three major categories: antibody-based, antibody fragment-based and pretargeted imaging. Radiolabeled anti-CEA antibodies, reported the earliest among the three categories, typically gave suboptimal tumor contrast due to the prolonged circulation life time of intact antibodies. Subsequently, a number of engineered anti-CEA antibody fragments (e.g. Fab’, scFv, minibody, diabody and scFv-Fc have been labeled with a variety of radioisotopes for CEA imaging, many of which have entered clinical investigation. CEA-Scan (a 99mTc-labeled anti-CEA Fab’ fragment has already been approved by the United States Food and Drug Administration for cancer imaging. Meanwhile, pretargeting strategies have also been developed for CEA imaging which can give much better tumor contrast than the other two methods, if the system is designed properly. In this review article, we will summarize the current state-of-the-art of radionuclide-based cancer imaging targeting CEA. Generally, isotopes with short half-lives (e.g. 18F and 99mTc are more suitable for labeling small engineered antibody fragments while the isotopes with longer half-lives (e.g. 123I and 111In are needed for antibody labeling to match its relatively long circulation half-life. With further improvement in tumor targeting efficacy and radiolabeling strategies, novel CEA-targeted agents may play an important role in cancer patient management, paving the way to “personalized medicine”.

  6. Radar Target Classification using Recursive Knowledge-Based Methods

    DEFF Research Database (Denmark)

    Jochumsen, Lars Wurtz

    The topic of this thesis is target classification of radar tracks from a 2D mechanically scanning coastal surveillance radar. The measurements provided by the radar are position data and therefore the classification is mainly based on kinematic data, which is deduced from the position. The target...... been terminated. Therefore, an update of the classification results must be made for each measurement of the target. The data for this work are collected throughout the PhD and are both collected from radars and other sensors such as GPS....... classes used in this work are classes, which are normal for coastal surveillance e.g.~ships, helicopters, birds etc. The classifier must be recursive as all data of a track is not present at any given moment. If all data were available, it would be too late to classify the track, as the track would have...

  7. Radar Target Recognition Based on Stacked Denoising Sparse Autoencoder

    Directory of Open Access Journals (Sweden)

    Zhao Feixiang

    2017-04-01

    Full Text Available Feature extraction is a key step in radar target recognition. The quality of the extracted features determines the performance of target recognition. However, obtaining the deep nature of the data is difficult using the traditional method. The autoencoder can learn features by making use of data and can obtain feature expressions at different levels of data. To eliminate the influence of noise, the method of radar target recognition based on stacked denoising sparse autoencoder is proposed in this paper. This method can extract features directly and efficiently by setting different hidden layers and numbers of iterations. Experimental results show that the proposed method is superior to the K-nearest neighbor method and the traditional stacked autoencoder.

  8. Target Image Matching Algorithm Based on Binocular CCD Ranging

    Directory of Open Access Journals (Sweden)

    Dongming Li

    2014-01-01

    Full Text Available This paper proposed target image in a subpixel level matching algorithm for binocular CCD ranging, which is based on the principle of binocular CCD ranging. In the paper, firstly, we introduced the ranging principle of the binocular ranging system and deduced a binocular parallax formula. Secondly, we deduced the algorithm which was named improved cross-correlation matching algorithm and cubic surface fitting algorithm for target images matched, and it could achieve a subpixel level matching for binocular CCD ranging images. Lastly, through experiment we have analyzed and verified the actual CCD ranging images, then analyzed the errors of the experimental results and corrected the formula of calculating system errors. Experimental results showed that the actual measurement accuracy of a target within 3 km was higher than 0.52%, which meet the accuracy requirements of the high precision binocular ranging.

  9. A proposed framework for consensus-based lung tumour volume auto-segmentation in 4D computed tomography imaging

    International Nuclear Information System (INIS)

    Martin, Spencer; Rodrigues, George; Gaede, Stewart; Brophy, Mark; Barron, John L; Beauchemin, Steven S; Palma, David; Louie, Alexander V; Yu, Edward; Yaremko, Brian; Ahmad, Belal

    2015-01-01

    This work aims to propose and validate a framework for tumour volume auto-segmentation based on ground-truth estimates derived from multi-physician input contours to expedite 4D-CT based lung tumour volume delineation. 4D-CT datasets of ten non-small cell lung cancer (NSCLC) patients were manually segmented by 6 physicians. Multi-expert ground truth (GT) estimates were constructed using the STAPLE algorithm for the gross tumour volume (GTV) on all respiratory phases. Next, using a deformable model-based method, multi-expert GT on each individual phase of the 4D-CT dataset was propagated to all other phases providing auto-segmented GTVs and motion encompassing internal gross target volumes (IGTVs) based on GT estimates (STAPLE) from each respiratory phase of the 4D-CT dataset. Accuracy assessment of auto-segmentation employed graph cuts for 3D-shape reconstruction and point-set registration-based analysis yielding volumetric and distance-based measures. STAPLE-based auto-segmented GTV accuracy ranged from (81.51  ±  1.92) to (97.27  ±  0.28)% volumetric overlap of the estimated ground truth. IGTV auto-segmentation showed significantly improved accuracies with reduced variance for all patients ranging from 90.87 to 98.57% volumetric overlap of the ground truth volume. Additional metrics supported these observations with statistical significance. Accuracy of auto-segmentation was shown to be largely independent of selection of the initial propagation phase. IGTV construction based on auto-segmented GTVs within the 4D-CT dataset provided accurate and reliable target volumes compared to manual segmentation-based GT estimates. While inter-/intra-observer effects were largely mitigated, the proposed segmentation workflow is more complex than that of current clinical practice and requires further development. (paper)

  10. Target Volume Delineation in Oropharyngeal Cancer: Impact of PET, MRI, and Physical Examination

    International Nuclear Information System (INIS)

    Thiagarajan, Anuradha; Caria, Nicola; Schöder, Heiko; Iyer, N. Gopalakrishna; Wolden, Suzanne; Wong, Richard J.; Sherman, Eric; Fury, Matthew G.; Lee, Nancy

    2012-01-01

    Introduction: Sole utilization of computed tomography (CT) scans in gross tumor volume (GTV) delineation for head-and-neck cancers is subject to inaccuracies. This study aims to evaluate contributions of magnetic resonance imaging (MRI), positron emission tomography (PET), and physical examination (PE) to GTV delineation in oropharyngeal cancer (OPC). Methods: Forty-one patients with OPC were studied. All underwent contrast-enhanced CT simulation scans (CECTs) that were registered with pretreatment PETs and MRIs. For each patient, three sets of primary and nodal GTV were contoured. First, reference GTVs (GTVref) were contoured by the treating radiation oncologist (RO) using CT, MRI, PET, and PE findings. Additional GTVs were created using fused CT/PET scans (GTVctpet) and CT/MRI scans (GTVctmr) by two other ROs blinded to GTVref. To compare GTVs, concordance indices (CI) were calculated by dividing the respective overlap volumes by overall volumes. To evaluate the contribution of PE, composite GTVs derived from CT, MRI, and PET (GTVctpetmr) were compared with GTVref. Results: For primary tumors, GTVref was significantly larger than GTVctpet and GTVctmr (p 0.75), indicating that although the modalities were complementary, the added benefit was small in the context of CECTs. In addition, PE did not aid greatly in nodal GTV delineation. Conclusion: PET and MRI are complementary and combined use is ideal. However, the low CI (ctpetmr vs. ref) particularly for primary tumors underscores the limitations of defining GTVs using imaging alone. PE is invaluable and must be incorporated.

  11. Targeted cellular ablation based on the morphology of malignant cells

    Science.gov (United States)

    Ivey, Jill W.; Latouche, Eduardo L.; Sano, Michael B.; Rossmeisl, John H.; Davalos, Rafael V.; Verbridge, Scott S.

    2015-11-01

    Treatment of glioblastoma multiforme (GBM) is especially challenging due to a shortage of methods to preferentially target diffuse infiltrative cells, and therapy-resistant glioma stem cell populations. Here we report a physical treatment method based on electrical disruption of cells, whose action depends strongly on cellular morphology. Interestingly, numerical modeling suggests that while outer lipid bilayer disruption induced by long pulses (~100 μs) is enhanced for larger cells, short pulses (~1 μs) preferentially result in high fields within the cell interior, which scale in magnitude with nucleus size. Because enlarged nuclei represent a reliable indicator of malignancy, this suggested a means of preferentially targeting malignant cells. While we demonstrate killing of both normal and malignant cells using pulsed electric fields (PEFs) to treat spontaneous canine GBM, we proposed that properly tuned PEFs might provide targeted ablation based on nuclear size. Using 3D hydrogel models of normal and malignant brain tissues, which permit high-resolution interrogation during treatment testing, we confirmed that PEFs could be tuned to preferentially kill cancerous cells. Finally, we estimated the nuclear envelope electric potential disruption needed for cell death from PEFs. Our results may be useful in safely targeting the therapy-resistant cell niches that cause recurrence of GBM tumors.

  12. Moving Beyond Motive-based categories of Targeted Violence

    Energy Technology Data Exchange (ETDEWEB)

    Weine, Stevan [Univ. of Illinois, Chicago, IL (United States); Cohen, John [Rutgers Univ., New Brunswick, NJ (United States); Brannegan, David [Argonne National Lab. (ANL), Argonne, IL (United States)

    2015-10-01

    Today’s categories for responding to targeted violence are motive-based and tend to drive policies, practices, training, media coverage, and research. These categories are based on the assumption that there are significant differences between ideological and non-ideological actors and between domestic and international actors. We question the reliance on these categories and offer an alternative way to frame the response to multiple forms of targeted violence. We propose adopting a community-based multidisciplinary approach to assess risk and provide interventions that are focused on the pre-criminal space. We describe four capabilities that should be implemented locally by establishing and maintaining multidisciplinary response teams that combine community and law-enforcement components: (1) community members are educated, making them better able to identify and report patterns associated with elevated risk for violence; (2) community-based professionals are trained to assess the risks for violent behavior posed by individuals; (3) community-based professionals learn to implement strategies that directly intervene in causal factors for those individuals who are at elevated risk; and (4) community-based professionals learn to monitor and assess an individual’s risk for violent behaviors on an ongoing basis. Community-based multidisciplinary response teams have the potential to identify and help persons in the pre-criminal space and to reduce barriers that have traditionally impeded community/law-enforcement collaboration.

  13. Target volume definition for 18F-FDG PET-positive lymph nodes in radiotherapy of patients with non-small cell lung cancer.

    Science.gov (United States)

    Nestle, Ursula; Schaefer-Schuler, Andrea; Kremp, Stephanie; Groeschel, Andreas; Hellwig, Dirk; Rübe, Christian; Kirsch, Carl-Martin

    2007-04-01

    FDG PET is increasingly used in radiotherapy planning. Recently, we demonstrated substantial differences in target volumes when applying different methods of FDG-based contouring in primary lung tumours (Nestle et al., J Nucl Med 2005;46:1342-8). This paper focusses on FDG-positive mediastinal lymph nodes (LN(PET)). In our institution, 51 NSCLC patients who were candidates for radiotherapy prospectively underwent staging FDG PET followed by a thoracic PET scan in the treatment position and a planning CT. Eleven of them had 32 distinguishable non-confluent mediastinal or hilar nodal FDG accumulations (LN(PET)). For these, sets of gross tumour volumes (GTVs) were generated at both acquisition times by four different PET-based contouring methods (visual: GTV(vis); 40% SUVmax: GTV40; SUV=2.5: GTV2.5; target/background (T/B) algorithm: GTV(bg)). All differences concerning GTV sizes were within the range of the resolution of the PET system. The detectability and technical delineability of the GTVs were significantly better in the late scans (e.g. p = 0.02 for diagnostic application of SUVmax = 2.5; p = 0.0001 for technical delineability by GTV2.5; p = 0.003 by GTV40), favouring the GTV(bg) method owing to satisfactory overall applicability and independence of GTVs from acquisition time. Compared with CT, the majority of PET-based GTVs were larger, probably owing to resolution effects, with a possible influence of lesion movements. For nodal GTVs, different methods of contouring did not lead to clinically relevant differences in volumes. However, there were significant differences in technical delineability, especially after early acquisition. Overall, our data favour a late acquisition of FDG PET scans for radiotherapy planning, and the use of a T/B algorithm for GTV contouring.

  14. Target volume definition for 18F-FDG PET-positive lymph nodes in radiotherapy of patients with non-small cell lung cancer

    International Nuclear Information System (INIS)

    Nestle, Ursula; Schaefer-Schuler, Andrea; Hellwig, Dirk; Kirsch, Carl-Martin; Kremp, Stephanie; Ruebe, Christian; Groeschel, Andreas

    2007-01-01

    FDG PET is increasingly used in radiotherapy planning. Recently, we demonstrated substantial differences in target volumes when applying different methods of FDG-based contouring in primary lung tumours (Nestle et al., J Nucl Med 2005;46:1342-8). This paper focusses on FDG-positive mediastinal lymph nodes (LN PET ). In our institution, 51 NSCLC patients who were candidates for radiotherapy prospectively underwent staging FDG PET followed by a thoracic PET scan in the treatment position and a planning CT. Eleven of them had 32 distinguishable non-confluent mediastinal or hilar nodal FDG accumulations (LN PET ). For these, sets of gross tumour volumes (GTVs) were generated at both acquisition times by four different PET-based contouring methods (visual: GTV vis ; 40% SUV max : GTV 40 ; SUV=2.5: GTV 2.5 ; target/background (T/B) algorithm: GTV bg ). All differences concerning GTV sizes were within the range of the resolution of the PET system. The detectability and technical delineability of the GTVs were significantly better in the late scans (e.g. p 0.02 for diagnostic application of SUV max = 2.5; p = 0.0001 for technical delineability by GTV 2.5 ; p = 0.003 by GTV 40 ), favouring the GTV bg method owing to satisfactory overall applicability and independence of GTVs from acquisition time. Compared with CT, the majority of PET-based GTVs were larger, probably owing to resolution effects, with a possible influence of lesion movements. For nodal GTVs, different methods of contouring did not lead to clinically relevant differences in volumes. However, there were significant differences in technical delineability, especially after early acquisition. Overall, our data favour a late acquisition of FDG PET scans for radiotherapy planning, and the use of a T/B algorithm for GTV contouring. (orig.)

  15. Variations in Target Volume Definition for Postoperative Radiotherapy in Stage III Non-Small-Cell Lung Cancer: Analysis of an International Contouring Study

    International Nuclear Information System (INIS)

    Spoelstra, Femke; Senan, Suresh; Le Pechoux, Cecile; Ishikura, Satoshi; Casas, Francesc; Ball, David; Price, Allan; De Ruysscher, Dirk; Soernsen de Koste, John R. van

    2010-01-01

    Purpose: Postoperative radiotherapy (PORT) in patients with completely resected non-small-cell lung cancer with mediastinal involvement is controversial because of the failure of earlier trials to demonstrate a survival benefit. Improved techniques may reduce toxicity, but the treatment fields used in routine practice have not been well studied. We studied routine target volumes used by international experts and evaluated the impact of a contouring protocol developed for a new prospective study, the Lung Adjuvant Radiotherapy Trial (Lung ART). Methods and Materials: Seventeen thoracic radiation oncologists were invited to contour their routine clinical target volumes (CTV) for 2 representative patients using a validated CD-ROM-based contouring program. Subsequently, the Lung ART study protocol was provided, and both cases were contoured again. Variations in target volumes and their dosimetric impact were analyzed. Results: Routine CTVs were received for each case from 10 clinicians, whereas six provided both routine and protocol CTVs for each case. Routine CTVs varied up to threefold between clinicians, but use of the Lung ART protocol significantly decreased variations. Routine CTVs in a postlobectomy patient resulted in V 20 values ranging from 12.7% to 54.0%, and Lung ART protocol CTVs resulted in values of 20.6% to 29.2%. Similar results were seen for other toxicity parameters and in the postpneumectomy patient. With the exception of upper paratracheal nodes, protocol contouring improved coverage of the required nodal stations. Conclusion: Even among experts, significant interclinician variations are observed in PORT fields. Inasmuch as contouring variations can confound the interpretation of PORT results, mandatory quality assurance procedures have been incorporated into the current Lung ART study.

  16. Experimental teaching and training system based on volume holographic storage

    Science.gov (United States)

    Jiang, Zhuqing; Wang, Zhe; Sun, Chan; Cui, Yutong; Wan, Yuhong; Zou, Rufei

    2017-08-01

    The experiment of volume holographic storage for teaching and training the practical ability of senior students in Applied Physics is introduced. The students can learn to use advanced optoelectronic devices and the automatic control means via this experiment, and further understand the theoretical knowledge of optical information processing and photonics disciplines that have been studied in some courses. In the experiment, multiplexing holographic recording and readout is based on Bragg selectivity of volume holographic grating, in which Bragg diffraction angle is dependent on grating-recording angel. By using different interference angle between reference and object beams, the holograms can be recorded into photorefractive crystal, and then the object images can be read out from these holograms via angular addressing by using the original reference beam. In this system, the experimental data acquisition and the control of the optoelectronic devices, such as the shutter on-off, image loaded in SLM and image acquisition of a CCD sensor, are automatically realized by using LabVIEW programming.

  17. Scattering Mechanism Identification Based on Polarimetric HRRP of Manmade Target

    Directory of Open Access Journals (Sweden)

    Wu Jiani

    2016-04-01

    Full Text Available In this paper, we analyze the space polarization and frequency dispersion characteristics of the polarimetric High Resolution Range Profile (HRRP of manmade targets. We integrate these characteristics and propose a novel scheme for scattering mechanism identification. Using a polarization decomposition technique, the scheme first identifies the scattering mechanism of the scattering centers. Specially, it uses an algorithm to compensate for the polarization orientation angle in order to decrease the errors in judgment caused by the varying azimuth. Then, based on the frequency dispersion characteristics, we design threedimensional parameters to discriminate between the scattering centers, in order to decrease the inaccuracy in the discriminations. Finally, we conduct simulations based on electromagnetic data to validate the feasibility of the proposed scheme and to demonstrate that it provides a basis for practical use in target recognition.

  18. Moving Target Information Extraction Based on Single Satellite Image

    Directory of Open Access Journals (Sweden)

    ZHAO Shihu

    2015-03-01

    Full Text Available The spatial and time variant effects in high resolution satellite push broom imaging are analyzed. A spatial and time variant imaging model is established. A moving target information extraction method is proposed based on a single satellite remote sensing image. The experiment computes two airplanes' flying speed using ZY-3 multispectral image and proves the validity of spatial and time variant model and moving information extracting method.

  19. RTOG Sarcoma Radiation Oncologists Reach Consensus on Gross Tumor Volume and Clinical Target Volume on Computed Tomographic Images for Preoperative Radiotherapy of Primary Soft Tissue Sarcoma of Extremity in Radiation Therapy Oncology Group Studies

    Energy Technology Data Exchange (ETDEWEB)

    Wang Dian, E-mail: dwang@mcw.edu [Medical College of Wisconsin, Milwaukee, WI (United States); Bosch, Walter [Washington University, St. Louis, MO (United States); Roberge, David [McGill University, Montreal, Quebec (Canada); Finkelstein, Steven E. [Moffitt Cancer Center, Tampa, FL (United States); Petersen, Ivy; Haddock, Michael [Mayo Clinic, Rochester, MN (United States); Chen, Yen-Lin E.; Saito, Naoyuki G. [Roswell Park Cancer Institute, Buffalo, NY (United States); Kirsch, David G. [Duke University, Durham, NC (United States); Hitchcock, Ying J. [University of Utah, Salt Lake City, UT (United States); Wolfson, Aaron H. [University of Miami Miller School of Medicine, Miami, FL (United States); DeLaney, Thomas F. [Massachusetts General Hospital, Boston, MA (United States)

    2011-11-15

    Objective: To develop a Radiation Therapy Oncology Group (RTOG) atlas delineating gross tumor volume (GTV) and clinical target volume (CTV) to be used for preoperative radiotherapy of primary extremity soft tissue sarcoma (STS). Methods and Materials: A consensus meeting was held during the RTOG meeting in January 2010 to reach agreement about GTV and CTV delineation on computed tomography (CT) images for preoperative radiotherapy of high-grade large extremity STS. Data were presented to address the local extension of STS. Extensive discussion ensued to develop optimal criteria for GTV and CTV delineation on CT images. Results: A consensus was reached on appropriate CT-based GTV and CTV. The GTV is gross tumor defined by T1 contrast-enhanced magnetic resonance images. Fusion of magnetic resonance and images is recommended to delineate the GTV. The CTV for high-grade large STS typically includes the GTV plus 3-cm margins in the longitudinal directions. If this causes the field to extend beyond the compartment, the field can be shortened to include the end of a compartment. The radial margin from the lesion should be 1.5 cm, including any portion of the tumor not confined by an intact fascial barrier, bone, or skin surface. Conclusion: The consensus on GTV and CTV for preoperative radiotherapy of high-grade large extremity STS is available as web-based images and in a descriptive format through the RTOG. This is expected to improve target volume consistency and allow for rigorous evaluation of the benefits and risks of such treatment.

  20. Comparison of internal target volumes defined on 3-dimensional, 4-dimensonal, and cone-beam CT images of non-small-cell lung cancer

    Directory of Open Access Journals (Sweden)

    Li F

    2016-11-01

    , and ITVMIP not included in ITVCBCT were 57.08%, 48.89%, and 20.04%, respectively. Conclusion: The use of the individual ITV derived from 4DCT merely based on bony registration in radiotherapy may result in a target miss. The ITVs derived from 3DCT with isotropic margins have a good coverage of the ITV from CBCT, but the use of those would result in a high proportion of normal tissue being irradiated unnecessarily. Keywords: non-small-cell lung cancer, cone-beam CT, four-dimensional CT, three-dimensional CT, internal target volume, volume comparison

  1. EPR-based material modelling of soils considering volume changes

    Science.gov (United States)

    Faramarzi, Asaad; Javadi, Akbar A.; Alani, Amir M.

    2012-11-01

    In this paper an approach is presented for developing material models for soils based on evolutionary polynomial regression (EPR), taking into account its volumetric behaviour. EPR is a recently developed hybrid data mining technique that searches for structured mathematical equations (representing the behaviour of a system) using genetic algorithm and the least squares method. Stress-strain data from triaxial test are used to train and develop EPR-based material models for soil. The developed models are compared with some of the well known conventional material models. In particular, the capability of the developed EPR models in predicting volume change behaviour of soils is illustrated. It is also shown that the developed EPR-based material models can be incorporated in finite element (FE) analysis. Two geotechnical examples are presented to verify the developed EPR-based FE model (EPR-FEM). The results of the EPR-FEM are compared with those of a standard FEM where conventional constitutive models are used to describe the material behaviour. The results show that EPR-FEM can be successfully employed to analyse geotechnical engineering problems. The advantages of the proposed EPR models are highlighted.

  2. A Deterministic Entropy Based on the Instantaneous Phase Space Volume

    Science.gov (United States)

    Diebner, Hans H.; Rössler, Otto E.

    1998-02-01

    A deterministic entropic measure is derived for the time evolution of Newtonian N-particle systems based on the volume of the instantaneously occupied phase space (IOPS). This measure is found as a natural extension of Boltzmann's entropy. The instantaneous arrangement of the particles is exploited in the form of spatial correlations. The new entropy is a bridge between the time-dependent Boltzmann entropy, formulated on the basis of densities in the one-particle phase space, and the static Gibbs entropy which uses densities in the full phase space. We apply the new concept in a molecular dynamics simulation (MDS) using an exactly time reversible "discrete Newtonian equation of motion" recently derived from the fundamental principle of least action in discretized space-time. The simulation therefore is consistent with micro-time-reversibility. Entropy becomes an exact momentary observable in both time directions in fulfillment of a dream of Boltzmann.

  3. Development of whole-building energy design targets for commercial buildings: Phase 1, Planning: Volume 2, Technical report

    Energy Technology Data Exchange (ETDEWEB)

    Crawley, D.B.; Briggs, R.S.; Jones, J.W.; Seaton, W.W.; Kaufman, J.E.; Deringer, J.J.; Kennett, E.W.

    1987-08-01

    This is the second volume of the Phase 1 report and discusses the 10 tasks performed in Phase 1. The objective of this research is to develop a methodology for setting energy design targets to provide voluntary guidelines for the buildings industry. The whole-building energy targets project is being conducted at the Pacific Northwest Laboratory (PNL) for the US Department of Energy (DOE) to encourage the construction of energy-efficient buildings by informing designers and owners about cost-effective goals for energy use in new commercial buildings. The outcome of this research will be a flexible methodology for setting such targets. The tasks are listed and discussed in this report as follows: Task 1 - Develop Detailed Project Goals and Objectives; Task 2 - Establish Buildings-Industry Liaison; Task 3 - Develop Approaches to the Energy Targets Model, Building Operations, and Climate; Task 4 - Develop an Approach for Treating Economic Considerations; Task 5 - Develop an Approach for Treating Energy Sources; Task 6 - Collect Energy-Use Data; Task 7 - Survey Energy Expert Opinion; Task 8 - Evaluation Procedure Specification and Integration; Task 9 - Phase 1 Report Development; and Task 10 - Phase 1 Review Planning.

  4. Atlas-based identification of targets for functional radiosurgery

    International Nuclear Information System (INIS)

    Stancanello, Joseph; Romanelli, Pantaleo; Modugno, Nicola; Cerveri, Pietro; Ferrigno, Giancarlo; Uggeri, Fulvio; Cantore, Giampaolo

    2006-01-01

    Functional disorders of the brain, such as Parkinson's disease, dystonia, epilepsy, and neuropathic pain, may exhibit poor response to medical therapy. In such cases, surgical intervention may become necessary. Modern surgical approaches to such disorders include radio-frequency lesioning and deep brain stimulation (DBS). The subthalamic nucleus (STN) is one of the most useful stereotactic targets available: STN DBS is known to induce substantial improvement in patients with end-stage Parkinson's disease. Other targets include the Globus Pallidus pars interna (GPi) for dystonia and Parkinson's disease, and the centromedian nucleus of the thalamus (CMN) for neuropathic pain. Radiosurgery is an attractive noninvasive alternative to treat some functional brain disorders. The main technical limitation to radiosurgery is that the target can be selected only on the basis of magnetic resonance anatomy without electrophysiological confirmation. The aim of this work is to provide a method for the correct atlas-based identification of the target to be used in functional neurosurgery treatment planning. The coordinates of STN, CMN, and GPi were identified in the Talairach and Tournoux atlas and transformed to the corresponding regions of the Montreal Neurological Institute (MNI) electronic atlas. Binary masks describing the target nuclei were created. The MNI electronic atlas was deformed onto the patient magnetic resonance imaging-T1 scan by applying an affine transformation followed by a local nonrigid registration. The first transformation was based on normalized cross correlation and the second on optimization of a two-part objective function consisting of similarity criteria and weighted regularization. The obtained deformation field was then applied to the target masks. The minimum distance between the surface of an implanted electrode and the surface of the deformed mask was calculated. The validation of the method consisted of comparing the electrode-mask distance to

  5. Physics of laser fusion. Volume II. Diagnostics of experiments on laser fusion targets at LLNL

    International Nuclear Information System (INIS)

    Ahlstrom, H.G.

    1982-01-01

    These notes present the experimental basis and status for laser fusion as developed at LLNL. There are two other volumes in this series: Vol. I, by C.E. Max, presents the theoretical laser-plasma interaction physics; Vol. III, by J.F. Holzrichter et al., presents the theory and design of high-power pulsed lasers. A fourth volume will present the theoretical implosion physics. The notes consist of six sections. The first, an introductory section, provides some of the history of inertial fusion and a simple explanation of the concepts involved. The second section presents an extensive discussion of diagnostic instrumentation used in the LLNL Laser Fusion Program. The third section is a presentation of laser facilities and capabilities at LLNL. The purpose here is to define capability, not to derive how it was obtained. The fourth and fifth sections present the experimental data on laser-plasma interaction and implosion physics. The last chapter is a short projection of the future

  6. Physics of laser fusion. Volume II. Diagnostics of experiments on laser fusion targets at LLNL

    Energy Technology Data Exchange (ETDEWEB)

    Ahlstrom, H.G.

    1982-01-01

    These notes present the experimental basis and status for laser fusion as developed at LLNL. There are two other volumes in this series: Vol. I, by C.E. Max, presents the theoretical laser-plasma interaction physics; Vol. III, by J.F. Holzrichter et al., presents the theory and design of high-power pulsed lasers. A fourth volume will present the theoretical implosion physics. The notes consist of six sections. The first, an introductory section, provides some of the history of inertial fusion and a simple explanation of the concepts involved. The second section presents an extensive discussion of diagnostic instrumentation used in the LLNL Laser Fusion Program. The third section is a presentation of laser facilities and capabilities at LLNL. The purpose here is to define capability, not to derive how it was obtained. The fourth and fifth sections present the experimental data on laser-plasma interaction and implosion physics. The last chapter is a short projection of the future.

  7. Monte-Carlo model development for evaluation of current clinical target volume definition for heterogeneous and hypoxic glioblastoma.

    Science.gov (United States)

    Moghaddasi, L; Bezak, E; Harriss-Phillips, W

    2016-05-07

    Clinical target volume (CTV) determination may be complex and subjective. In this work a microscopic-scale tumour model was developed to evaluate current CTV practices in glioblastoma multiforme (GBM) external radiotherapy. Previously, a Geant4 cell-based dosimetry model was developed to calculate the dose deposited in individual GBM cells. Microscopic extension probability (MEP) models were then developed using Matlab-2012a. The results of the cell-based dosimetry model and MEP models were combined to calculate survival fractions (SF) for CTV margins of 2.0 and 2.5 cm. In the current work, oxygenation and heterogeneous radiosensitivity profiles were incorporated into the GBM model. The genetic heterogeneity was modelled using a range of α/β values (linear-quadratic model parameters) associated with different GBM cell lines. These values were distributed among the cells randomly, taken from a Gaussian-weighted sample of α/β values. Cellular oxygen pressure was distributed randomly taken from a sample weighted to profiles obtained from literature. Three types of GBM models were analysed: homogeneous-normoxic, heterogeneous-normoxic, and heterogeneous-hypoxic. The SF in different regions of the tumour model and the effect of the CTV margin extension from 2.0-2.5 cm on SFs were investigated for three MEP models. The SF within the beam was increased by up to three and two orders of magnitude following incorporation of heterogeneous radiosensitivities and hypoxia, respectively, in the GBM model. However, the total SF was shown to be overdominated by the presence of tumour cells in the penumbra region and to a lesser extent by genetic heterogeneity and hypoxia. CTV extension by 0.5 cm reduced the SF by a maximum of 78.6  ±  3.3%, 78.5  ±  3.3%, and 77.7  ±  3.1% for homogeneous and heterogeneous-normoxic, and heterogeneous hypoxic GBMs, respectively. Monte-Carlo model was developed to quantitatively evaluate SF for genetically

  8. Improved targeted immunization strategies based on two rounds of selection

    Science.gov (United States)

    Xia, Ling-Ling; Song, Yu-Rong; Li, Chan-Chan; Jiang, Guo-Ping

    2018-04-01

    In the case of high degree targeted immunization where the number of vaccine is limited, when more than one node associated with the same degree meets the requirement of high degree centrality, how can we choose a certain number of nodes from those nodes, so that the number of immunized nodes will not exceed the limit? In this paper, we introduce a new idea derived from the selection process of second-round exam to solve this problem and then propose three improved targeted immunization strategies. In these proposed strategies, the immunized nodes are selected through two rounds of selection, where we increase the quotas of first-round selection according the evaluation criterion of degree centrality and then consider another characteristic parameter of node, such as node's clustering coefficient, betweenness and closeness, to help choose targeted nodes in the second-round selection. To validate the effectiveness of the proposed strategies, we compare them with the degree immunizations including the high degree targeted and the high degree adaptive immunizations using two metrics: the size of the largest connected component of immunized network and the number of infected nodes. Simulation results demonstrate that the proposed strategies based on two rounds of sorting are effective for heterogeneous networks and their immunization effects are better than that of the degree immunizations.

  9. A method to combine target volume data from 3D and 4D planned thoracic radiotherapy patient cohorts for machine learning applications

    NARCIS (Netherlands)

    Johnson, Corinne; Price, Gareth; Khalifa, Jonathan; Faivre-Finn, Corinne; Dekker, Andre; Moore, Christopher; van Herk, Marcel

    2017-01-01

    The gross tumour volume (GTV) is predictive of clinical outcome and consequently features in many machine-learned models. 4D-planning, however, has prompted substitution of the GTV with the internal gross target volume (iGTV). We present and validate a method to synthesise GTV data from the iGTV,

  10. Histopathological correlation of 11C-choline PET scans for target volume definition in radical prostate radiotherapy

    International Nuclear Information System (INIS)

    Chang, Joe H.; Joon, Daryl Lim; Lee, Sze Ting; Gong, Sylvia J.; Scott, Andrew M.; Davis, Ian D.; Clouston, David; Bolton, Damien; Hamilton, Christopher S.; Khoo, Vincent

    2011-01-01

    Background and purpose: To evaluate the accuracy of 11 C-choline PET scans in defining dominant intraprostatic lesions (DILs) for radiotherapy target volume definition. Material and methods: Eight men with prostate cancer who had 11 C-choline PET scans prior to radical prostatectomy were studied. Several methods were used to contour the DIL on the PET scans: visual, PET Edge, Region Grow, absolute standardised uptake value (SUV) thresholds and percentage of maximum SUV thresholds. Prostatectomy specimens were sliced in the transverse plane and DILs were delineated on these by a pathologist. These were then compared with the PET scans. The accuracy of correlation was assessed by the Dice similarity coefficient (DSC) and the Youden index. Results: The contouring method resulting in both the highest DSC and the highest Youden index was 60% of the maximum SUV (SUV 60% ), with values of 0.64 and 0.51, respectively. However SUV 60% was not statistically significantly better than all of the other methods by either measure. Conclusions: Although not statistically significant, SUV 60% resulted in the best correlation between 11 C-choline PET and pathology amongst all the methods studied. The degree of correlation shown here is consistent with previous studies that have justified using imaging for DIL radiotherapy target volume definition.

  11. Surfaced-based investigations plan, Volume 4: Yucca Mountain Project

    International Nuclear Information System (INIS)

    1988-12-01

    This document represents a detailed summary of design plans for surface-based investigations to be conducted for site characterization of the Yucca Mountain site. These plans are current as of December 1988. The description of surface-based site characterization activities contained in this document is intended to give all interested parties an understanding of the current plans for site characterization of Yucca Mountain. The maps presented in Volume 4 are products of the Geographic Information System (GIS) being used by the Yucca Mountain Project. The ARC/INFO GIS software, developed by Environmental Systems Research Institute, was used to digitize and process these SBIP maps. The maps were prepared using existing US Geological Survey (USGS) maps as a planimetric base. Roads and other surface features were interpreted from a variety of sources and entered into the GIS. Sources include the USGS maps, 1976 USGS orthophotoquads and aerial photography, 1986 and 1987 aerial photography, surveyed coordinates of field sites, and a combination of various maps, figures, descriptions and approximate coordinates of proposed locations for future activities

  12. Internal target volume for post-hysterectomy vaginal recurrences of cervical cancers during image-guided radiotherapy.

    Science.gov (United States)

    Upasani, Maheshkumar N; Chopra, Supriya; Engineer, Reena; Mahantshetty, Umesh; Medhi, Seema; Mehta, Zubin; Shrivastava, Shyam K

    2015-10-01

    The outcome of post-surgical recurrences of cervical cancer may be improved through radiation dose escalation, which hinges on accurate identification and treatment of the target. The present study quantifies target motion during course of image-guided radiotherapy (IGRT) for vault cancers. All patients underwent planning CT simulation after bladder-filling protocol. A daily pre-treatment megavoltage CT was performed. All translations and rotations were recorded. Post-registration displacement of gross tumour volume (GTV) and centre of mass (COM) of GTV was independently recorded by two observers for fractions one to seven. Day 1 image sets served as reference images against which the displacements of COM were measured. We calculated the displacements of common volume (CV) and encompassing volume (EV) of GTV for both the observers. A total of 90 image data sets of 15 patients were available for evaluation. Individual patient GTV and average GTV by both the observers were comparable. The average shifts for EV were 2.4 mm [standard deviation (SD) ±1.2] in the mediolateral, 4.2 mm (SD ±2.8) in the anteroposterior and 4.0 mm (SD ±2.1) in superoinferior directions. Similarly, the average shifts for CV were 1.9 mm (SD ±0.6) in the mediolateral, 3.7 mm (SD ±2.7) in the anteroposterior and 4.4 mm (SD ±2.7) in superoinferior directions. Using Stroom's/van Herk's formula, the minimum recommended margins would be 4.5/5.2, 8.2/9.4 and 7.3/8.3 mm, respectively, for lateral, anteroposterior and superoinferior directions. Differential directional internal margin is recommended in patients undergoing IGRT for post-surgical recurrence of cervical cancers. Internal organ motion of vault cancers can be accounted for by a directional margin to the gross tumour.

  13. Research on moving target defense based on SDN

    Science.gov (United States)

    Chen, Mingyong; Wu, Weimin

    2017-08-01

    An address mutation strategy was proposed. This strategy provided an unpredictable change in address, replacing the real address of the packet forwarding process and path mutation, thus hiding the real address of the host and path. a mobile object defense technology based on Spatio-temporal Mutation on this basis is proposed, Using the software Defined Network centralized control architecture advantage combines sFlow traffic monitoring technology and Moving Target Defense. A mutated time period which can be changed in real time according to the network traffic is changed, and the destination address is changed while the controller abruptly changes the address while the data packet is transferred between the switches to construct a moving target, confusing the host within the network, thereby protecting the host and network.

  14. Graphite oxide based targets applied in laser matter interaction

    Science.gov (United States)

    Cutroneo, Mariapompea; Torrisi, Lorenzo; Badziak, Jan; Rosinski, Marcin; Havranek, Vladimir; Mackova, Anna; Malinsky, Petr; Sofer, Zdenek; Luxa, Jan; Cannavò, Antonino; Lorincik, Jan

    2018-01-01

    In the present work, we propose the production of a hybrid graphene based material suitable to be laser irradiated with the aim to produce quasi-monoenergetic proton beams using a femtosecond laser system. The unique lattice structure of the irradiated solid thin target can affect the inside electron propagation, their outgoing from the rear side of a thin foil, and subsequently the plasma ion acceleration. The produced targets, have been characterized in composition, roughness and structure and for completeness irradiated. The yield and energy of the ions emitted from the laser-generated plasma have been monitored and the emission of proton stream profile exhibited an acceleration of the order of several MeVs/charge state.

  15. Assessment of planning target volume margins for intensity-modulated radiotherapy of the prostate gland: role of daily inter- and intrafraction motion.

    Science.gov (United States)

    Tanyi, James A; He, Tongming; Summers, Paige A; Mburu, Ruth G; Kato, Catherine M; Rhodes, Stephen M; Hung, Arthur Y; Fuss, Martin

    2010-12-01

    To determine planning target volume margins for prostate intensity-modulated radiotherapy based on inter- and intrafraction motion using four daily localization techniques: three-point skin mark alignment, volumetric imaging with bony landmark registration, volumetric imaging with implanted fiducial marker registration, and implanted electromagnetic transponders (beacons) detection. Fourteen patients who underwent definitive intensity-modulated radiotherapy for prostate cancer formed the basis of this study. Each patient was implanted with three electromagnetic transponders and underwent a course of 39 treatment fractions. Daily localization was based on three-point skin mark alignment followed by transponder detection and patient repositioning. Transponder positioning was verified by volumetric imaging with cone-beam computed tomography of the pelvis. Relative motion between the prostate gland and bony anatomy was quantified by offline analyses of daily cone-beam computed tomography. Intratreatment organ motion was monitored continuously by the Calypso® System for quantification of intrafraction setup error. As expected, setup error (that is, inter- plus intrafraction motion, unless otherwise stated) was largest with skin mark alignment, requiring margins of 7.5 mm, 11.4 mm, and 16.3 mm, in the lateral (LR), longitudinal (SI), and vertical (AP) directions, respectively. Margin requirements accounting for intrafraction motion were smallest for transponder detection localization techniques, requiring margins of 1.4 mm (LR), 2.6 mm (SI), and 2.3 mm (AP). Bony anatomy alignment required 2.1 mm (LR), 9.4 mm (SI), and 10.5 mm (AP), whereas image-guided marker alignment required 2.8 mm (LR), 3.7 mm (SI), and 3.2 mm (AP). No marker migration was observed in the cohort. Clinically feasible, rapid, and reliable tools such as the electromagnetic transponder detection system for pretreatment target localization and, subsequently, intratreatment target location monitoring

  16. Multimodality Imaging with Silica-Based Targeted Nanoparticle Platforms

    International Nuclear Information System (INIS)

    Lewis, Jason S.

    2012-01-01

    Objectives: To synthesize and characterize a C-Dot silica-based nanoparticle containing 'clickable' groups for the subsequent attachment of targeting moieties (e.g., peptides) and multiple contrast agents (e.g., radionuclides with high specific activity) (1,2). These new constructs will be tested in suitable tumor models in vitro and in vivo to ensure maintenance of target-specificity and high specific activity. Methods: Cy5 dye molecules are cross-linked to a silica precursor which is reacted to form a dye-rich core particle. This core is then encapsulated in a layer of pure silica to create the core-shell C-Dot (Figure 1) (2). A 'click' chemistry approach has been used to functionalize the silica shell with radionuclides conferring high contrast and specific activity (e.g. 64Cu and 89Zr) and peptides for tumor targeting (e.g. cRGD and octreotate) (3). Based on the selective Diels-Alder reaction between tetrazine and norbornene, the reaction is bioorthogonal, highyielding, rapid, and water-compatible. This radiolabeling approach has already been employed successfully with both short peptides (e.g. octreotate) and antibodies (e.g. trastuzumab) as model systems for the ultimate labeling of the nanoparticles (1). Results: PEGylated C-Dots with a Cy5 core and labeled with tetrazine have been synthesized (d = 55 nm, zeta potential = -3 mV) reliably and reproducibly and have been shown to be stable under physiological conditions for up to 1 month. Characterization of the nanoparticles revealed that the immobilized Cy5 dye within the C-Dots exhibited fluorescence intensities over twice that of the fluorophore alone. The nanoparticles were successfully radiolabeled with Cu-64. Efforts toward the conjugation of targeting peptides (e.g. cRGD) are underway. In vitro stability, specificity, and uptake studies as well as in vivo imaging and biodistribution investigations will be presented. Conclusions: C-Dot silica-based nanoparticles offer a robust, versatile, and multi

  17. Multimodality Imaging with Silica-Based Targeted Nanoparticle Platforms

    Energy Technology Data Exchange (ETDEWEB)

    Jason S. Lewis

    2012-04-09

    Objectives: To synthesize and characterize a C-Dot silica-based nanoparticle containing 'clickable' groups for the subsequent attachment of targeting moieties (e.g., peptides) and multiple contrast agents (e.g., radionuclides with high specific activity) [1,2]. These new constructs will be tested in suitable tumor models in vitro and in vivo to ensure maintenance of target-specificity and high specific activity. Methods: Cy5 dye molecules are cross-linked to a silica precursor which is reacted to form a dye-rich core particle. This core is then encapsulated in a layer of pure silica to create the core-shell C-Dot (Figure 1) [2]. A 'click' chemistry approach has been used to functionalize the silica shell with radionuclides conferring high contrast and specific activity (e.g. 64Cu and 89Zr) and peptides for tumor targeting (e.g. cRGD and octreotate) [3]. Based on the selective Diels-Alder reaction between tetrazine and norbornene, the reaction is bioorthogonal, highyielding, rapid, and water-compatible. This radiolabeling approach has already been employed successfully with both short peptides (e.g. octreotate) and antibodies (e.g. trastuzumab) as model systems for the ultimate labeling of the nanoparticles [1]. Results: PEGylated C-Dots with a Cy5 core and labeled with tetrazine have been synthesized (d = 55 nm, zeta potential = -3 mV) reliably and reproducibly and have been shown to be stable under physiological conditions for up to 1 month. Characterization of the nanoparticles revealed that the immobilized Cy5 dye within the C-Dots exhibited fluorescence intensities over twice that of the fluorophore alone. The nanoparticles were successfully radiolabeled with Cu-64. Efforts toward the conjugation of targeting peptides (e.g. cRGD) are underway. In vitro stability, specificity, and uptake studies as well as in vivo imaging and biodistribution investigations will be presented. Conclusions: C-Dot silica-based nanoparticles offer a robust

  18. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy

    2014-05-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  19. Dynamic Garment Simulation based on Hybrid Bounding Volume Hierarchy

    Directory of Open Access Journals (Sweden)

    Zhu Dongyong

    2016-12-01

    Full Text Available In order to solve the computing speed and efficiency problem of existing dynamic clothing simulation, this paper presents a dynamic garment simulation based on a hybrid bounding volume hierarchy. It firstly uses MCASG graph theory to do the primary segmentation for a given three-dimensional human body model. And then it applies K-means cluster to do the secondary segmentation to collect the human body’s upper arms, lower arms, upper legs, lower legs, trunk, hip and woman’s chest as the elementary units of dynamic clothing simulation. According to different shapes of these elementary units, it chooses the closest and most efficient hybrid bounding box to specify these units, such as cylinder bounding box and elliptic cylinder bounding box. During the process of constructing these bounding boxes, it uses the least squares method and slices of the human body to get the related parameters. This approach makes it possible to use the least amount of bounding boxes to create close collision detection regions for the appearance of the human body. A spring-mass model based on a triangular mesh of the clothing model is finally constructed for dynamic simulation. The simulation result shows the feasibility and superiority of the method described.

  20. Effect of interfractional shoulder motion on low neck nodal targets for patients treated using volume modulated arc therapy (VMAT

    Directory of Open Access Journals (Sweden)

    Kevin Casey

    2014-03-01

    Full Text Available Purpose: To quantify the dosimetric impact of interfractional shoulder motion on targets in the low neck for head and neck patients treated with volume modulated arc therapy (VMAT.Methods: Three patients with head and neck cancer were selected. All three required treatment to nodal regions in the low neck in addition to the primary tumor site. The patients were immobilized during simulation and treatment with a custom thermoplastic mask covering the head and shoulders. One VMAT plan was created for each patient utilizing two full 360° arcs and a second plan was created consisting of two superior VMAT arcs matched to an inferior static AP supraclavicular field. A CT-on-rails alignment verification was performed weekly during each patient’s treatment course. The weekly CT images were registered to the simulation CT and the target contours were deformed and applied to the weekly CT. The two VMAT plans were copied to the weekly CT datasets and recalculated to obtain the dose to the deformed low neck contours.Results: The average observed shoulder position shift in any single dimension relative to simulation was 2.5 mm. The maximum shoulder shift observed in a single dimension was 25.7 mm. Low neck target mean doses, normalized to simulation and averaged across all weekly recalculations were 0.996, 0.991, and 1.033 (Full VMAT plan and 0.986, 0.995, and 0.990 (Half-Beam VMAT plan for the three patients, respectively. The maximum observed deviation in target mean dose for any individual weekly recalculation was 6.5%, occurring with the Full VMAT plan for Patient 3.Conclusion: Interfractional variation in dose to low neck nodal regions was quantified for three head and neck patients treated with VMAT. Mean dose was 3.3% higher than planned for one patient using a Full VMAT plan. A Half-Beam technique is likely a safer choice when treating the supraclavicular region with VMAT.-------------------------------------------Cite this article as: Casey K

  1. Tailoring peritoneal dialysis fluid for optimal acid-base targets.

    Science.gov (United States)

    Feriani, Mariano

    2009-01-01

    Mild derangements of acid-base status are common features in peritoneal dialysis patients, metabolic acidosis being the most frequent alteration. One of the main tasks of dialysis is to correct these derangements and the target is the normalization of the acid-base parameters since they affect several organs and functions. Since factors affecting acid-base homeostasis are intrinsic characteristics of the individual patient (metabolic acid production, distribution space for bicarbonate, dialytic prescription, etc.), it is not surprising that only relatively few patients achieve the normal range. Only a certain modulation of buffer infusion by using different buffer concentrations in the dialysis fluid may ensure a good correction in a large percentage of patients.

  2. Quantitative prediction of respiratory tidal volume based on the external torso volume change: a potential volumetric surrogate

    International Nuclear Information System (INIS)

    Li Guang; Arora, Naveen C; Xie Huchen; Ning, Holly; Citrin, Deborah; Kaushal, Aradhana; Zach, Leor; Camphausen, Kevin; Miller, Robert W; Lu Wei; Low, Daniel

    2009-01-01

    An external respiratory surrogate that not only highly correlates with but also quantitatively predicts internal tidal volume should be useful in guiding four-dimensional computed tomography (4DCT), as well as 4D radiation therapy (4DRT). A volumetric surrogate should have advantages over external fiducial point(s) for monitoring respiration-induced motion of the torso, which deforms in synchronization with a patient-specific breathing pattern. This study establishes a linear relationship between the external torso volume change (TVC) and lung air volume change (AVC) by validating a proposed volume conservation hypothesis (TVC = AVC) throughout the respiratory cycle using 4DCT and spirometry. Fourteen patients' torso 4DCT images and corresponding spirometric tidal volumes were acquired to examine this hypothesis. The 4DCT images were acquired using dual surrogates in cine mode and amplitude-based binning in 12 respiratory stages, minimizing residual motion artifacts. Torso and lung volumes were calculated using threshold-based segmentation algorithms and volume changes were calculated relative to the full-exhalation stage. The TVC and AVC, as functions of respiratory stages, were compared, showing a high correlation (r = 0.992 ± 0.005, p 2 = 0.980) without phase shift. The AVC was also compared to the spirometric tidal volumes, showing a similar linearity (slope = 1.030 ± 0.092, R 2 = 0.947). In contrast, the thoracic and abdominal heights measured from 4DCT showed relatively low correlation (0.28 ± 0.44 and 0.82 ± 0.30, respectively) and location-dependent phase shifts. This novel approach establishes the foundation for developing an external volumetric respiratory surrogate.

  3. Quantitative prediction of respiratory tidal volume based on the external torso volume change: a potential volumetric surrogate

    Energy Technology Data Exchange (ETDEWEB)

    Li Guang; Arora, Naveen C; Xie Huchen; Ning, Holly; Citrin, Deborah; Kaushal, Aradhana; Zach, Leor; Camphausen, Kevin; Miller, Robert W [Radiation Oncology Branch, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892 (United States); Lu Wei; Low, Daniel [Department of Radiation Oncology, Washington University School of Medicine, St Louis, MO 63110 (United States)], E-mail: ligeorge@mail.nih.gov

    2009-04-07

    An external respiratory surrogate that not only highly correlates with but also quantitatively predicts internal tidal volume should be useful in guiding four-dimensional computed tomography (4DCT), as well as 4D radiation therapy (4DRT). A volumetric surrogate should have advantages over external fiducial point(s) for monitoring respiration-induced motion of the torso, which deforms in synchronization with a patient-specific breathing pattern. This study establishes a linear relationship between the external torso volume change (TVC) and lung air volume change (AVC) by validating a proposed volume conservation hypothesis (TVC = AVC) throughout the respiratory cycle using 4DCT and spirometry. Fourteen patients' torso 4DCT images and corresponding spirometric tidal volumes were acquired to examine this hypothesis. The 4DCT images were acquired using dual surrogates in cine mode and amplitude-based binning in 12 respiratory stages, minimizing residual motion artifacts. Torso and lung volumes were calculated using threshold-based segmentation algorithms and volume changes were calculated relative to the full-exhalation stage. The TVC and AVC, as functions of respiratory stages, were compared, showing a high correlation (r = 0.992 {+-} 0.005, p < 0.0001) as well as a linear relationship (slope = 1.027 {+-} 0.061, R{sup 2} = 0.980) without phase shift. The AVC was also compared to the spirometric tidal volumes, showing a similar linearity (slope = 1.030 {+-} 0.092, R{sup 2} = 0.947). In contrast, the thoracic and abdominal heights measured from 4DCT showed relatively low correlation (0.28 {+-} 0.44 and 0.82 {+-} 0.30, respectively) and location-dependent phase shifts. This novel approach establishes the foundation for developing an external volumetric respiratory surrogate.

  4. The ADVANCE project: Formal evaluation of the targeted deployment. Volume 3

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    ADVANCE [Advanced Driver and Vehicle Advisory Navigation ConcEpt] was a public/private partnership conceived and developed by four founding parties. The founding parties include the Federal Highway Administration (FHWA), the Illinois Department of Transportation (IDOT), the University of Illinois at Chicago and Northwestern University operating together under the auspices of the Illinois Universities Transportation Research Consortium (IUTRC), and Motorola, Inc. The major responsibilities of each party are fully described in the Project agreement. Subsequently, these four were joined on the Steering Committee by the American Automobile Association (AAA). This unique blending of public sector, private sector and university interests, augmented by more than two dozen other private sector participants, provided a strong set of resources for ADVANCE. The ADVANCE test area covered over 300 square miles including portions of the City of Chicago and 40 northwest suburban communities. The Project encompasses the high growth areas adjacent to O`Hare International Airport, the Schaumbura/Hoffman Estates office and retail complexes, and the Lake-Cook Road development corridor. It also includes major sports and entertainment complexes such as the Arlington International Racecourse and the Rosemont Horizon. The population in the area is more than 750,000. This volume provides a summary of the insights and achievements made as a result of this field test, and selected appendices containing more detailed information.

  5. SAR Target Recognition with Feature Fusion Based on Stacked Autoencoder

    Directory of Open Access Journals (Sweden)

    Kang Miao

    2017-04-01

    Full Text Available A feature fusion algorithm based on a Stacked AutoEncoder (SAE for Synthetic Aperture Rader (SAR imagery is proposed in this paper. Firstly, 25 baseline features and Three-Patch Local Binary Patterns (TPLBP features are extracted. Then, the features are combined in series and fed into the SAE network, which is trained by a greedy layer-wise method. Finally, the softmax classifier is employed to fine tune the SAE network for better fusion performance. Additionally, the Gabor texture features of SAR images are extracted, and the fusion experiments between different features are carried out. The results show that the baseline features and TPLBP features have low redundancy and high complementarity, which makes the fused feature more discriminative. Compared with the SAR target recognition algorithm based on SAE or CNN (Convolutional Neural Network, the proposed method simplifies the network structure and increases the recognition accuracy and efficiency. 10-classes SAR targets based on an MSTAR dataset got a classification accuracy up to 95.88%, which verifies the effectiveness of the presented algorithm.

  6. A moving target detecting and tracking system based on DSP

    Science.gov (United States)

    Cai, Daonan; Zhao, Yuejin; Liu, Ming; Dong, Liquan; Liu, Xiaohua

    2018-01-01

    In order to solve the target fast tracking problem in embedded system, a moving target detecting and tracking algorithm based on a combination of three-frame difference and template matching is proposed. The system utilizes DSP to design a set of image processing equipment and DSP uses TI company's DM6437.Three-frame difference can detect a initial position of the target, then Mean Normalized Product Correlation(NNPROD) template matching algorithm was utilized in a partial area to achieve a precise position and reduce the amount of calculation. The algorithm utilized four templates and image compression to fit pose and scale changes when moving. To meet the real-time requirement, an improved algorithm of NNPROD was proposed under certain lighting conditions, what ' s more the C language code was optimized and TI company's highly optimized VLIB vision library was reasonably utilized. After several tests, the results showed that NNPROD can fit the changing of environmental light well, but more time was needed. The improved method can still work well with the changes of pose and scale when the light changes less intensely , and the processing speed of the improved method increased from the previous 11F / s to 23F / s.

  7. Financing Target and Resale Pricing in Reward-Based Crowdfunding

    Directory of Open Access Journals (Sweden)

    Lei Xu

    2018-04-01

    Full Text Available Resale is an effective tool for reward-based crowdfunding creators to make more profit after crowdfunding successfully. On the one hand, funds raised during the crowdfunding affect the resale pricing as a capital constraint; on the other hand, backers’ strategic purchasing behavior in the resale stage can also disturb the creator’s financing target decision-making through affecting resale pricing. In view of this, this paper builds a two-stage crowdfunding model to examine the interaction between the financing target and resale pricing in the presence of strategic backers. The results show that a lower financing amount leads to higher prices in the resale stage due to the rationing effect, and suppresses price volatility due to strategic purchasing behavior. In contrast, a higher financing amount enables the creator to build a large capacity, which does not restrict the resale prices and profit. Besides, in the context of high unit production cost or high backer patience level, there is no need for the creator to set a high financing target at the risk of crowdfunding failure.

  8. NETWORK BASED BUSINESS MODEL INNOVATION TARGETING THE BOP MARKET

    DEFF Research Database (Denmark)

    Ravn, Jacob; Kroghstrup Nielsen, Martin; Lindgren, Peter

    2009-01-01

    Through innovation of products, process and business models targeting the needs of 4 billion poor people living at "the base of pyramid" (BoP) (Prahalad & Hart 2002) in developing countries the private sector can actively support poverty alleviation and at the same time reach new untouched market...... countries seems to show up in the literature: The technological line - exemplified by the - exemplified by the Life Straw business model - a high tech "straw" consisting of 12 chemical filters to purify water - an example of technology driven innovation to meet the BoP demands for clean water (Kandachar...

  9. [A new calibration transfer method based on target factor analysis].

    Science.gov (United States)

    Wang, Yan-bin; Yuan, Hong-fu; Lu, Wan-zhen

    2005-03-01

    A new calibration transfer method based on target factor analysis is proposed.The performance of the new method compared with the piecewise direct standardization method. This method was applied to two data sets, of which one is a simulation data set, and the other is an NIR data set composed of benzene, toluene, xylene and isooctane. The results obtained with this new method are at least as well as those obtained by PDS with the biggest improvement occurring when the spectra have some non-linear responses.

  10. SU-E-J-75: Importance of 4DCT for Target Volume Definition in Stereotactic Lung Radiotherapy

    International Nuclear Information System (INIS)

    Goksel, E; Cone, D; Kucucuk, H; Senkesen, O; Yilmaz, M; Aslay, I; Tezcanli, E; Garipagaoglu, M; Sengoz, M

    2014-01-01

    Purpose: We aimed to investigate the importance of 4DCT for lung tumors treated with SBRT and whether maximum intensity projection (MIP) and free breathing (FB) images can compansate for tumor movement. Methods: Six patients with primary lung cancer and 2 patients with lung metastasis with a median age of 69.5 (42–86) were included. Patients were positioned supine on a vacuum bag. In addition to FB planning CT images, 4DCT images were obtained at 3 mm intervals using Varian RPM system with (Siemens Somatom Sensetion 64). MIP series were reconstructed using 4DCT images. PTV-FB and PTV-MIP (GTV+5mm) volumes were contoured using FB and MIP series, respectively. GTVs were defined on each of eight different breathing phase images and were merged to create the ITV. PTV-4D was generated with a 5 mm margin to ITV. PTV-MIP and PTV-4D contours were copied to FB CT series and treatment plans for PTV-MIP and PTV-FB were generated using RapidArc (2 partial arc) technique in Eclipse (version 11, AAA algorithm). The prescription dose was 5600cGy in 7 fractions. ITV volumes receiving prescription dose (%) and V95 for ITV were calculated for each treatment plan. Results: The mean PTV-4B, PTV-MIP and PTV-FB volumes were 23.2 cc, 15.4cc ve 11cc respectively. Median volume of ITV receiving the prescription dose was 34.6% (16.4–70 %) and median V95 dose for ITV was 1699cGy (232cGy-5117cGy) in the plan optimized for PTV-FB as the reference. When the plan was optimized for PTV-MIP, median ITV volume receiving the prescription dose was 67.15% (26–86%) and median V95 dose for ITV was 4231cGy (1735cGy-5290cGy). Conclusion: Images used in lung SBRT are critical for treatment quality; FB and MIP images did not compensate target movement, therefore 4DCT images should be obtained for all patients undergoing lung SBRT or the safety margins should be adjusted

  11. Planning target volume margins for prostate radiotherapy using daily electronic portal imaging and implanted fiducial markers

    International Nuclear Information System (INIS)

    Skarsgard, David; Cadman, Pat; El-Gayed, Ali; Pearcey, Robert; Tai, Patricia; Pervez, Nadeem; Wu, Jackson

    2010-01-01

    Fiducial markers and daily electronic portal imaging (EPI) can reduce the risk of geographic miss in prostate cancer radiotherapy. The purpose of this study was to estimate CTV to PTV margin requirements, without and with the use of this image guidance strategy. 46 patients underwent placement of 3 radio-opaque fiducial markers prior to prostate RT. Daily pre-treatment EPIs were taken, and isocenter placement errors were corrected if they were ≥ 3 mm along the left-right or superior-inferior axes, and/or ≥ 2 mm along the anterior-posterior axis. During-treatment EPIs were then obtained to estimate intra-fraction motion. Without image guidance, margins of 0.57 cm, 0.79 cm and 0.77 cm, along the left-right, superior-inferior and anterior-posterior axes respectively, are required to give 95% probability of complete CTV coverage each day. With the above image guidance strategy, these margins can be reduced to 0.36 cm, 0.37 cm and 0.37 cm respectively. Correction of all isocenter placement errors, regardless of size, would permit minimal additional reduction in margins. Image guidance, using implanted fiducial markers and daily EPI, permits the use of narrower PTV margins without compromising coverage of the target, in the radiotherapy of prostate cancer

  12. Rhamnogalacturonan-I Based Microcapsules for Targeted Drug Release.

    Science.gov (United States)

    Svagan, Anna J; Kusic, Anja; De Gobba, Cristian; Larsen, Flemming H; Sassene, Philip; Zhou, Qi; van de Weert, Marco; Mullertz, Anette; Jørgensen, Bodil; Ulvskov, Peter

    2016-01-01

    Drug targeting to the colon via the oral administration route for local treatment of e.g. inflammatory bowel disease and colonic cancer has several advantages such as needle-free administration and low infection risk. A new source for delivery is plant-polysaccharide based delivery platforms such as Rhamnogalacturonan-I (RG-I). In the gastro-intestinal tract the RG-I is only degraded by the action of the colonic microflora. For assessment of potential drug delivery properties, RG-I based microcapsules (~1 μm in diameter) were prepared by an interfacial poly-addition reaction. The cross-linked capsules were loaded with a fluorescent dye (model drug). The capsules showed negligible and very little in vitro release when subjected to media simulating gastric and intestinal fluids, respectively. However, upon exposure to a cocktail of commercial RG-I cleaving enzymes, ~ 9 times higher release was observed, demonstrating that the capsules can be opened by enzymatic degradation. The combined results suggest a potential platform for targeted drug delivery in the terminal gastro-intestinal tract.

  13. In silico design of targeted SRM-based experiments

    Directory of Open Access Journals (Sweden)

    Nahnsen Sven

    2012-11-01

    Full Text Available Abstract Selected reaction monitoring (SRM-based proteomics approaches enable highly sensitive and reproducible assays for profiling of thousands of peptides in one experiment. The development of such assays involves the determination of retention time, detectability and fragmentation properties of peptides, followed by an optimal selection of transitions. If those properties have to be identified experimentally, the assay development becomes a time-consuming task. We introduce a computational framework for the optimal selection of transitions for a given set of proteins based on their sequence information alone or in conjunction with already existing transition databases. The presented method enables the rapid and fully automated initial development of assays for targeted proteomics. We introduce the relevant methods, report and discuss a step-wise and generic protocol and we also show that we can reach an ad hoc coverage of 80 % of the targeted proteins. The presented algorithmic procedure is implemented in the open-source software package OpenMS/TOPP.

  14. Design and implementation of location-based wireless targeted advertising

    Science.gov (United States)

    Li, Benjamin; Xu, Deyin

    2001-10-01

    As advertisements are time and location sensitive, a challenge for wireless marketing is to have advertisements delivered when and where they are most convenient. In this paper we introduce a two-stage auction model for location-based wireless targeted advertising. This system extends the notion of location-based service by using location information to target advertising, and does so specifically by enabling advertisers to specify their preferences and bid for advertisement delivery, where those preferences are then used in a subsequent automated auction of actual deliveries to wireless data users. The automated auction in the second stage is especially effective because it can use information about the individual user profile data, including customer relationship management system contents as well as location from the wireless system's location management service, including potentially location history such as current trajectory from recent history and longer-term historical trip records for that user. Through two-stage auction, real-time bidding by advertisers and matching ads contents to mobile users help advertising information reach maximal value.

  15. Rhamnogalacturonan-I based microcapsules for targeted drug release

    DEFF Research Database (Denmark)

    Svagan, Anna J.; Kusic, Anja; De Gobba, Cristian

    2016-01-01

    Drug targeting to the colon via the oral administration route for local treatment of e.g. inflammatory bowel disease and colonic cancer has several advantages such as needle-free administration and low infection risk. A new source for delivery is plant-polysaccharide based delivery platforms...... such as Rhamnogalacturonan-I (RG-I). In the gastro-intestinal tract the RG-I is only degraded by the action of the colonic microflora. For assessment of potential drug delivery properties, RG-I based microcapsules (~1 μm in diameter) were prepared by an interfacial poly-addition reaction. The cross-linked capsules were...... loaded with a fluorescent dye (model drug). The capsules showed negligible and very little in vitro release when subjected to media simulating gastric and intestinal fluids, respectively. However, upon exposure to a cocktail of commercial RG-I cleaving enzymes, ~ 9 times higher release was observed...

  16. Discovery based and targeted Mass Spectrometry in farm animal proteomics

    DEFF Research Database (Denmark)

    Bendixen, Emøke

    2013-01-01

    for investigating farm animal biology. SRM is particularly important for validation biomarker candidates This talk will introduce the use of different mass spectrometry approaches through examples related to food quality and animal welfare, including studies of gut health in pigs, host pathogen interactions......Technological advances in mass spectrometry have greatly improved accuracy and speed of analyses of proteins and biochemical pathways. These proteome technologies have transformed research and diagnostic methods in the biomedical fields, and in food and farm animal sciences proteomics can be used...... be monitored to improve welfare in large industrial settings of current livestock industry. The combination of discovery based LC-MS/MS methods and the more hypothesis-based targeted mass spectrometry method commonly referred to as selected reaction monitoring or SRM, provide a powerful approach...

  17. Multimodality imaging with CT, MR and FDG-PET for radiotherapy target volume delineation in oropharyngeal squamous cell carcinoma

    International Nuclear Information System (INIS)

    Bird, David; Scarsbrook, Andrew F.; Sykes, Jonathan; Ramasamy, Satiavani; Subesinghe, Manil; Carey, Brendan; Wilson, Daniel J.; Roberts, Neil; McDermott, Gary; Karakaya, Ebru; Bayman, Evrim; Sen, Mehmet; Speight, Richard; Prestwich, Robin J.D.

    2015-01-01

    This study aimed to quantify the variation in oropharyngeal squamous cell carcinoma gross tumour volume (GTV) delineation between CT, MR and FDG PET-CT imaging. A prospective, single centre, pilot study was undertaken where 11 patients with locally advanced oropharyngeal cancers (2 tonsil, 9 base of tongue primaries) underwent pre-treatment, contrast enhanced, FDG PET-CT and MR imaging, all performed in a radiotherapy treatment mask. CT, MR and CT-MR GTVs were contoured by 5 clinicians (2 radiologists and 3 radiation oncologists). A semi-automated segmentation algorithm was used to contour PET GTVs. Volume and positional analyses were undertaken, accounting for inter-observer variation, using linear mixed effects models and contour comparison metrics respectively. Significant differences in mean GTV volume were found between CT (11.9 cm 3 ) and CT-MR (14.1 cm 3 ), p < 0.006, CT-MR and PET (9.5 cm 3 ), p < 0.0009, and MR (12.7 cm 3 ) and PET, p < 0.016. Substantial differences in GTV position were found between all modalities with the exception of CT-MR and MR GTVs. A mean of 64 %, 74 % and 77 % of the PET GTVs were included within the CT, MR and CT-MR GTVs respectively. A mean of 57 % of the MR GTVs were included within the CT GTV; conversely a mean of 63 % of the CT GTVs were included within the MR GTV. CT inter-observer variability was found to be significantly higher in terms of position and/or volume than both MR and CT-MR (p < 0.05). Significant differences in GTV volume were found between GTV volumes delineated by radiologists (9.7 cm 3 ) and oncologists (14.6 cm 3 ) for all modalities (p = 0.001). The use of different imaging modalities produced significantly different GTVs, with no single imaging technique encompassing all potential GTV regions. The use of MR reduced inter-observer variability. These data suggest delineation based on multimodality imaging has the potential to improve accuracy of GTV definition. ISRCTN Registry: ISRCTN34165059. Registered 2

  18. SU-C-BRA-05: Delineating High-Dose Clinical Target Volumes for Head and Neck Tumors Using Machine Learning Algorithms

    International Nuclear Information System (INIS)

    Cardenas, C; Wong, A; Mohamed, A; Fuller, C; Yang, J; Court, L; Aristophanous, M; Rao, A

    2016-01-01

    Purpose: To develop and test population-based machine learning algorithms for delineating high-dose clinical target volumes (CTVs) in H&N tumors. Automating and standardizing the contouring of CTVs can reduce both physician contouring time and inter-physician variability, which is one of the largest sources of uncertainty in H&N radiotherapy. Methods: Twenty-five node-negative patients treated with definitive radiotherapy were selected (6 right base of tongue, 11 left and 9 right tonsil). All patients had GTV and CTVs manually contoured by an experienced radiation oncologist prior to treatment. This contouring process, which is driven by anatomical, pathological, and patient specific information, typically results in non-uniform margin expansions about the GTV. Therefore, we tested two methods to delineate high-dose CTV given a manually-contoured GTV: (1) regression-support vector machines(SVM) and (2) classification-SVM. These models were trained and tested on each patient group using leave-one-out cross-validation. The volume difference(VD) and Dice similarity coefficient(DSC) between the manual and auto-contoured CTV were calculated to evaluate the results. Distances from GTV-to-CTV were computed about each patient’s GTV and these distances, in addition to distances from GTV to surrounding anatomy in the expansion direction, were utilized in the regression-SVM method. The classification-SVM method used categorical voxel-information (GTV, selected anatomical structures, else) from a 3×3×3cm3 ROI centered about the voxel to classify voxels as CTV. Results: Volumes for the auto-contoured CTVs ranged from 17.1 to 149.1cc and 17.4 to 151.9cc; the average(range) VD between manual and auto-contoured CTV were 0.93 (0.48–1.59) and 1.16(0.48–1.97); while average(range) DSC values were 0.75(0.59–0.88) and 0.74(0.59–0.81) for the regression-SVM and classification-SVM methods, respectively. Conclusion: We developed two novel machine learning methods to delineate

  19. SU-C-BRA-05: Delineating High-Dose Clinical Target Volumes for Head and Neck Tumors Using Machine Learning Algorithms

    Energy Technology Data Exchange (ETDEWEB)

    Cardenas, C [Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); The University of Texas Graduate School of Biomedical Sciences, Houston, TX (United States); Wong, A [Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); School of Medicine, The University of Texas Health Sciences Center at San Antonio, San Antonio, TX (United States); Mohamed, A; Fuller, C [Department of Radiation Oncology, The University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Yang, J; Court, L; Aristophanous, M [Department of Radiation Physics, The University of Texas M.D. Anderson Cancer Center, Houston, TX (United States); Rao, A [Department of Bioinformatics and Computational Biology, The University of Texas M.D. Anderson Cancer Center, Houston, TX (United States)

    2016-06-15

    Purpose: To develop and test population-based machine learning algorithms for delineating high-dose clinical target volumes (CTVs) in H&N tumors. Automating and standardizing the contouring of CTVs can reduce both physician contouring time and inter-physician variability, which is one of the largest sources of uncertainty in H&N radiotherapy. Methods: Twenty-five node-negative patients treated with definitive radiotherapy were selected (6 right base of tongue, 11 left and 9 right tonsil). All patients had GTV and CTVs manually contoured by an experienced radiation oncologist prior to treatment. This contouring process, which is driven by anatomical, pathological, and patient specific information, typically results in non-uniform margin expansions about the GTV. Therefore, we tested two methods to delineate high-dose CTV given a manually-contoured GTV: (1) regression-support vector machines(SVM) and (2) classification-SVM. These models were trained and tested on each patient group using leave-one-out cross-validation. The volume difference(VD) and Dice similarity coefficient(DSC) between the manual and auto-contoured CTV were calculated to evaluate the results. Distances from GTV-to-CTV were computed about each patient’s GTV and these distances, in addition to distances from GTV to surrounding anatomy in the expansion direction, were utilized in the regression-SVM method. The classification-SVM method used categorical voxel-information (GTV, selected anatomical structures, else) from a 3×3×3cm3 ROI centered about the voxel to classify voxels as CTV. Results: Volumes for the auto-contoured CTVs ranged from 17.1 to 149.1cc and 17.4 to 151.9cc; the average(range) VD between manual and auto-contoured CTV were 0.93 (0.48–1.59) and 1.16(0.48–1.97); while average(range) DSC values were 0.75(0.59–0.88) and 0.74(0.59–0.81) for the regression-SVM and classification-SVM methods, respectively. Conclusion: We developed two novel machine learning methods to delineate

  20. A Target Advertisement System Based on TV Viewer's Profile Reasoning

    Science.gov (United States)

    Lim, Jeongyeon; Kim, Munjo; Lee, Bumshik; Kim, Munchurl; Lee, Heekyung; Lee, Han-Kyu

    With the rapidly growing Internet, the Internet broadcasting and web casting service have been one of the well-known services. Specially, it is expected that the IPTV service will be one of the principal services in the broadband network [2]. However, the current broadcasting environment is served for the general public and requires the passive attitude to consume the TV programs. For the advanced broadcasting environments, various research of the personalized broadcasting is needed. For example, the current unidirectional advertisement provides to the TV viewers the advertisement contents, depending on the popularity of TV programs, the viewing rates, the age groups of TV viewers, and the time bands of the TV programs being broadcast. It is not an efficient way to provide the useful information to the TV viewers from customization perspective. If a TV viewer does not need particular advertisement contents, then information may be wasteful to the TV viewer. Therefore, it is expected that the target advertisement service will be one of the important services in the personalized broadcasting environments. The current research in the area of the target advertisement classifies the TV viewers into clustered groups who have similar preference. The digital TV collaborative filtering estimates the user's favourite advertisement contents by using the usage history [1, 4, 5]. In these studies, the TV viewers are required to provide their profile information such as the gender, job, and ages to the service providers via a PC or Set-Top Box (STB) which is connected to digital TV. Based on explicit information, the advertisement contents are provided to the TV viewers in a customized way with tailored advertisement contents. However, the TV viewers may dislike exposing to the service providers their private information because of the misuse of it. In this case, it is difficult to provide appropriate target advertisement service.

  1. Targeted albumin-based nanoparticles for delivery of amphipathic drugs.

    Science.gov (United States)

    Xu, Rongzuo; Fisher, Michael; Juliano, R L

    2011-05-18

    We report the preparation and physical and biological characterization of human serum albumin-based micelles of approximately 30 nm diameter for the delivery of amphipathic drugs, represented by doxorubicin. The micelles were surface conjugated with cyclic RGD peptides to guide selective delivery to cells expressing the α(v)β(3) integrin. Multiple poly(ethylene glycol)s (PEGs) with molecular weight of 3400 Da were used to form a hydrophilic outer layer, with the inner core formed by albumin conjugated with doxorubicin via disulfide bonds. Additional doxorubicin was physically adsorbed into this core to attain a high drug loading capacity, where each albumin was associated with about 50 doxorubicin molecules. The formed micelles were stable in serum but continuously released doxorubicin when incubated with free thiols at concentrations mimicking the intracellular environment. When incubated with human melanoma cells (M21+) that express the α(v)β(3) integrin, higher uptake and longer retention of doxorubicin was observed with the RGD-targeted micelles than in the case of untargeted control micelles or free doxorubicin. Consequently, the RGD-targeted micelles manifested cytotoxicity at lower doses of drug than control micelles or free drug.

  2. Feature extraction algorithm for space targets based on fractal theory

    Science.gov (United States)

    Tian, Balin; Yuan, Jianping; Yue, Xiaokui; Ning, Xin

    2007-11-01

    In order to offer a potential for extending the life of satellites and reducing the launch and operating costs, satellite servicing including conducting repairs, upgrading and refueling spacecraft on-orbit become much more frequently. Future space operations can be more economically and reliably executed using machine vision systems, which can meet real time and tracking reliability requirements for image tracking of space surveillance system. Machine vision was applied to the research of relative pose for spacecrafts, the feature extraction algorithm was the basis of relative pose. In this paper fractal geometry based edge extraction algorithm which can be used in determining and tracking the relative pose of an observed satellite during proximity operations in machine vision system was presented. The method gets the gray-level image distributed by fractal dimension used the Differential Box-Counting (DBC) approach of the fractal theory to restrain the noise. After this, we detect the consecutive edge using Mathematical Morphology. The validity of the proposed method is examined by processing and analyzing images of space targets. The edge extraction method not only extracts the outline of the target, but also keeps the inner details. Meanwhile, edge extraction is only processed in moving area to reduce computation greatly. Simulation results compared edge detection using the method which presented by us with other detection methods. The results indicate that the presented algorithm is a valid method to solve the problems of relative pose for spacecrafts.

  3. Improving routing efficiency through intermediate target based geographic routing

    Directory of Open Access Journals (Sweden)

    Zongming Fei

    2015-08-01

    Full Text Available The greedy strategy of geographical routing may cause the local minimum problem when there is a hole in the routing area. It depends on other strategies such as perimeter routing to find a detour path, which can be long and result in inefficiency of the routing protocol. In this paper, we propose a new approach called Intermediate Target based Geographic Routing (ITGR to solve the long detour path problem. The basic idea is to use previous experience to determine the destination areas that are shaded by the holes. The novelty of the approach is that a single forwarding path can be used to determine a shaded area that may cover many destination nodes. We design an efficient method for the source to find out whether a destination node belongs to a shaded area. The source then selects an intermediate node as the tentative target and greedily forwards packets to it, which in turn forwards the packet to the final destination by greedy routing. ITGR can combine multiple shaded areas to improve the efficiency of representation and routing. We perform simulations and demonstrate that ITGR significantly reduces the routing path length, compared with existing geographic routing protocols.

  4. Determination of the optimal statistical uncertainty to perform electron-beam Monte Carlo absorbed dose estimation in the target volume; Determination de l'incertitude statistique optimale pour realiser un calcul de dose dans le volume cible en utilisant la methode de Monte Carlo

    Energy Technology Data Exchange (ETDEWEB)

    Isambert, A.; Lefkopoulos, D. [Institut Gustave-Roussy, Medical Physics Dept., 94 - Villejuif (France); Brualla, L. [NCTeam, Strahlenklinik, Universitatsklinikum Essen (Germany); Benkebil, M. [DOSIsoft, 94 - Cachan (France)

    2010-04-15

    Purpose of study Monte Carlo based treatment planning system are known to be more accurate than analytical methods for performing absorbed dose estimation, particularly in and near heterogeneities. However, the required computation time can still be an issue. The present study focused on the determination of the optimum statistical uncertainty in order to minimise computation time while keeping the reliability of the absorbed dose estimation in treatments planned with electron-beams. Materials and methods Three radiotherapy plans (medulloblastoma, breast and gynaecological) were used to investigate the influence of the statistical uncertainty of the absorbed dose on the target volume dose-volume histograms (spinal cord, intra-mammary nodes and pelvic lymph nodes, respectively). Results The study of the dose-volume histograms showed that for statistical uncertainty levels (1 S.D.) above 2 to 3%, the standard deviation of the mean dose in the target volume calculated from the dose-volume histograms increases by at least 6%, reflecting the gradual flattening of the dose-volume histograms. Conclusions This work suggests that, in clinical context, Monte Carlo based absorbed dose estimations should be performed with a maximum statistical uncertainty of 2 to 3%. (authors)

  5. Design, simulation and manufacture of a multi leaf collimator to confirm the target volumes in intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Kamali-Asl, A.; Batooli, A. H.; Harriri, S.; Salman-Rezaee, F.; Shahmardan, F.; Yavari, L.

    2010-01-01

    Intensity modulated radiation therapy is one of the cancer treatment methods. It is important to selectively aim at the target in this way, which can be performed using a multi leaf collimator. Materials and Methods: In order to specifically irradiate the target volume in radiotherapy to reduce the patient absorbed dose, the use of multi leaf collimator has been investigated in this work. Design and simulation of an multi leaf collimator was performed by a Monte Carlo method and the optimum material for manufacturing the leaves was determined using MCNP4C. After image processing (CT or MRI) in this system, the tumor configuration is determined. Then the linear accelerator is switched on and the beam irradiates the cancerous cells. When the multi leaf collimator leaves receive a command from the micro controller, they start to move and absorb the radiation and modulate its intensity. Consequently, the tumor receives maximum intensity of radiation but minimum intensity is delivered to healthy tissues. Results: According to the simulations and calculations, the best material to manufacture the leaves from is tungsten alloy containing copper and nickel which absorbs a large amount of the radiation; by using a 8.65 cm thickness of alloy, 10.55% of radiation will transmit through the leaves. Discussion and Conclusion: Lead blocks are conventionally used in radiotherapy. However, they have some problems like cost, storage and manufacture for every patient. Certainly, the multi leaf collimator is the most efficient device to specifically irradiate the tumor in Intensity modulated radiation therapy. Furthermore, it facilitates treating the target in different views by rotation around the patient. Thus the patient's absorbed dose will decrease and the tumor will receive maximum dose.

  6. Facilities for preparing actinide or fission product-based targets

    CERN Document Server

    Sors, M

    1999-01-01

    Research and development work is currently in progress in France on the feasibility of transmutation of very long-lived radionuclides such as americium, blended with an inert medium such as magnesium oxide and pelletized for irradiation in a fast neutron reactor. The process is primarily designed to produce ceramics for nuclear reactors, but could also be used to produce targets for accelerators. The Actinide Development Laboratory is part of the ATALANTE complex at Marcoule, where the CEA investigates reprocessing, liquid and solid waste treatment and vitrification processes. The laboratory produces radioactive sources; after use, their constituents are recycled, notably through R and D programs requiring such materials. Recovered americium is purified, characterized and transformed for an experiment known as ECRIX, designed to demonstrate the feasibility of fabricating americium-based ceramics and to determine the reactor transmutation coefficients.

  7. Daily ultrasound-based image-guided targeting for radiotherapy of upper abdominal malignancies.

    Science.gov (United States)

    Fuss, Martin; Salter, Bill J; Cavanaugh, Sean X; Fuss, Cristina; Sadeghi, Amir; Fuller, Clifton D; Ameduri, Ardow; Hevezi, James M; Herman, Terence S; Thomas, Charles R

    2004-07-15

    Development and implementation of a strategy to use a stereotactic ultrasound (US)-based image-guided targeting device (BAT) to align intensity-modulated radiotherapy (IMRT) target volumes accurately in the upper abdomen. Because the outlines of such targets may be poorly visualized by US, we present a method that uses adjacent vascular guidance structures as surrogates for the target position. We assessed the potential for improvement of daily repositioning and the feasibility of daily application. A total of 62 patients were treated by sequential tomotherapeutic IMRT between October 2000 and June 2003 for cholangiocarcinoma and gallbladder carcinoma (n = 10), hepatocellular carcinoma (n = 10), liver metastases (n = 11), pancreatic carcinoma (n = 20), neuroblastoma (n = 3), and other abdominal and retroperitoneal tumors (n = 8). The target volumes (TVs) and organs at risk were delineated in contrast-enhanced CT data sets. Additionally, vascular guidance structures in close anatomic relation to the TV, or within the TV, were delineated. Throughout the course of IMRT, US BAT images were acquired during daily treatment positioning. In addition to the anatomic structures typically used for US targeting (e.g., the TV and dose-limiting organs at risk), CT contours of guidance structures were superimposed onto the real-time acquired axial and sagittal US images, and target position adjustments, as indicated by the system, were performed accordingly. We report the BAT-derived distribution of shifts in the three principal room axes compared with a skin-mark-based setup, as well as the time required to perform BAT alignment. The capability of the presented method to improve target alignment was assessed in 15 patients by comparing the organ and fiducial position between the respective treatment simulation CT with a control CT study after US targeting in the CT suite. A total of 1,337 BAT alignments were attempted. US images were not useful in 56 setups (4.2%), mainly

  8. Control volume based hydrocephalus research; a phantom study

    Science.gov (United States)

    Cohen, Benjamin; Voorhees, Abram; Madsen, Joseph; Wei, Timothy

    2009-11-01

    Hydrocephalus is a complex spectrum of neurophysiological disorders involving perturbation of the intracranial contents; primarily increased intraventricular cerebrospinal fluid (CSF) volume and intracranial pressure are observed. CSF dynamics are highly coupled to the cerebral blood flows and pressures as well as the mechanical properties of the brain. Hydrocephalus, as such, is a very complex biological problem. We propose integral control volume analysis as a method of tracking these important interactions using mass and momentum conservation principles. As a first step in applying this methodology in humans, an in vitro phantom is used as a simplified model of the intracranial space. The phantom's design consists of a rigid container filled with a compressible gel. Within the gel a hollow spherical cavity represents the ventricular system and a cylindrical passage represents the spinal canal. A computer controlled piston pump supplies sinusoidal volume fluctuations into and out of the flow phantom. MRI is used to measure fluid velocity and volume change as functions of time. Independent pressure measurements and momentum flow rate measurements are used to calibrate the MRI data. These data are used as a framework for future work with live patients and normal individuals. Flow and pressure measurements on the flow phantom will be presented through the control volume framework.

  9. RAIL TRAFFIC VOLUME ESTIMATION BASED ON WORLD DEVELOPMENT INDICATORS

    Directory of Open Access Journals (Sweden)

    Luka Lazarević

    2015-08-01

    Full Text Available European transport policy, defined in the White Paper, supports shift from road to rail and waterborne transport. The hypothesis of the paper is that changes in the economic environment influence rail traffic volume. Therefore, a model for prediction of rail traffic volume applied in different economic contexts could be a valuable tool for the transport planners. The model was built using common Machine Learning techniques that learn from the past experience. In the model preparation, world development indicators defined by the World Bank were used as input parameters.

  10. Control volume based modelling of compressible flow in reciprocating machines

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2004-01-01

    conservation laws for mass, energy, and momentum applied to a staggered mesh consisting of two overlapping strings of control volumes. Loss mechanisms can be included directly in the governing equations of models by including them as terms in the conservation laws. Heat transfer, flow friction......, and multidimensional effects must be calculated using empirical correlations; correlations for steady state flow can be used as an approximation. A transformation that assumes ideal gas is presented for transforming equations for masses and energies in control volumes into the corresponding pressures and temperatures...

  11. Target detection method by airborne and spaceborne images fusion based on past images

    Science.gov (United States)

    Chen, Shanjing; Kang, Qing; Wang, Zhenggang; Shen, ZhiQiang; Pu, Huan; Han, Hao; Gu, Zhongzheng

    2017-11-01

    To solve the problem that remote sensing target detection method has low utilization rate of past remote sensing data on target area, and can not recognize camouflage target accurately, a target detection method by airborne and spaceborne images fusion based on past images is proposed in this paper. The target area's past of space remote sensing image is taken as background. The airborne and spaceborne remote sensing data is fused and target feature is extracted by the means of airborne and spaceborne images registration, target change feature extraction, background noise suppression and artificial target feature extraction based on real-time aerial optical remote sensing image. Finally, the support vector machine is used to detect and recognize the target on feature fusion data. The experimental results have established that the proposed method combines the target area change feature of airborne and spaceborne remote sensing images with target detection algorithm, and obtains fine detection and recognition effect on camouflage and non-camouflage targets.

  12. Reduced relative volume in motor and attention regions in developmental coordination disorder: A voxel-based morphometry study.

    Science.gov (United States)

    Reynolds, Jess E; Licari, Melissa K; Reid, Siobhan L; Elliott, Catherine; Winsor, Anne M; Bynevelt, Michael; Billington, Jac

    2017-05-01

    Developmental coordination disorder (DCD) is a prevalent childhood movement disorder, impacting the ability to perform movement skills at an age appropriate level. Although differences in grey matter (GM) volumes have been found in related developmental disorders, no such evidence has been linked with DCD to date. This cross-sectional study assessed structural brain differences in children with and without DCD. High-resolution structural images were acquired from 44 children aged 7.8-12 years, including 22 children with DCD (≤16th percentile on MABC-2; no ADHD/ASD), and 22 typically developing controls (≥20th percentile on MABC-2). Structural voxel-based morphology analysis was performed to determine group differences in focal GM volumes. Children with DCD were found to have significant, large, right lateralised reductions in grey matter volume in the medial and middle frontal, and superior frontal gyri compared to controls. The addition of motor proficiency as a covariate explained the between-group GM volume differences, suggesting that GM volumes in motor regions are reflective of the level of motor proficiency. A positive correlation between motor proficiency and relative GM volume was also identified in the left posterior cingulate and precuneus. GM volume reductions in premotor frontal regions may underlie the motor difficulties characteristic of DCD. It is possible that intervention approaches targeting motor planning, attention, and executive functioning processes associated with the regions of reduced GM volume may result in functional improvements in children with DCD. Copyright © 2017 ISDN. Published by Elsevier Ltd. All rights reserved.

  13. SU-F-T-36: Dosimetric Comparison of Point Based Vs. Target Based Prescription for Intracavitary Brachytherapy in Cancer of the Cervix

    Energy Technology Data Exchange (ETDEWEB)

    Ashenafi, M; McDonald, D; Peng, J; Mart, C; Koch, N; Cooper, L; Vanek, K [Medical University of South Carolina, Charleston, SC (United States)

    2016-06-15

    Purpose: Improved patient imaging used for planning the treatment of cervical cancer with Tandem and Ovoid (T&O) Intracavitary high-dose-rate brachytherapy (HDR) now allows for 3D delineation of target volumes and organs-at-risk. However, historical data relies on the conventional point A-based planning technique. A comparative dosimetric study was performed by generating both target-based (TBP) and point-based (PBP) plans for ten clinical patients. Methods: Treatment plans created using Elekta Oncentra v. 4.3 for ten consecutive cervical cancer patients were analyzed. All patients were treated with HDR using the Utrecht T&O applicator. Both CT and MRI imaging modalities were utilized to delineate clinical target volume (CTV) and organs-at-risk (rectum, sigmoid, bladder, and small bowel). Point A (left and right), vaginal mucosa, and ICRU rectum and bladder points were defined on CT. Two plans were generated for each patient using two prescription methods (PBP and TBP). 7Gy was prescribed to each point A for each PBP plan and to the target D90% for each TBP plan. Target V90%, V100%, and V200% were evaluated. In addition, D0.1cc and D2cc were analyzed for each organ-at-risk. Differences were assessed for statistical significance (p<0.05) by use of Student’s t-test. Results: Target coverage was comparable for both planning methods, with each method providing adequate target coverage. TBP showed lower absolute dose to the target volume than PBP (D90% = 7.0Gy vs. 7.4Gy, p=0.028), (V200% = 10.9cc vs. 12.8cc, p=0.014), (ALeft = 6.4Gy vs. 7Gy, p=0.009), and (ARight = 6.4Gy vs. 7Gy, p=0.013). TBP also showed a statistically significant reduction in bladder, rectum, small bowel, and sigmoid doses compared to PBP. There was no statistically significant difference in vaginal mucosa or ICRU-defined rectum and bladder dose. Conclusion: Target based prescription resulted in substantially lower dose to delineated organs-at-risk compared to point based prescription, while

  14. A Prospective Pathologic Study to Define the Clinical Target Volume for Partial Breast Radiation Therapy in Women With Early Breast Cancer

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Brandon T., E-mail: Brandon.Nguyen@act.gov.au [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Canberra Hospital, Radiation Oncology Department, Garran, ACT (Australia); Deb, Siddhartha [Department of Anatomical Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Victorian Cancer Biobank, Cancer Council of Victoria, Carlton, Victoria (Australia); Fox, Stephen [Department of Anatomical Pathology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Hill, Prudence [Department of Anatomical Pathology, St. Vincent' s Hospital Melbourne, Fitzroy, Victoria (Australia); Collins, Marnie [Centre for Biostatistics and Clinical Trials, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); Chua, Boon H. [Department of Radiation Oncology, Peter MacCallum Cancer Centre, East Melbourne, Victoria (Australia); University of Melbourne, Parkville, Victoria (Australia)

    2012-12-01

    Purpose: To determine an appropriate clinical target volume for partial breast radiation therapy (PBRT) based on the spatial distribution of residual invasive and in situ carcinoma after wide local excision (WLE) for early breast cancer or ductal carcinoma in situ (DCIS). Methods and Materials: We performed a prospective pathologic study of women potentially eligible for PBRT who had re-excision and/or completion mastectomy after WLE for early breast cancer or DCIS. A pathologic assessment protocol was used to determine the maximum radial extension (MRE) of residual carcinoma from the margin of the initial surgical cavity. Women were stratified by the closest initial radial margin width: negative (>1 mm), close (>0 mm and {<=}1 mm), or involved. Results: The study population was composed of 133 women with a median age of 59 years (range, 27-82 years) and the following stage groups: 0 (13.5%), I (40.6%), II (38.3%), and III (7.5%). The histologic subtypes of the primary tumor were invasive ductal carcinoma (74.4%), invasive lobular carcinoma (12.0%), and DCIS alone (13.5%). Residual carcinoma was present in the re-excision and completion mastectomy specimens in 55.4%, 14.3%, and 7.2% of women with an involved, close, and negative margin, respectively. In the 77 women with a noninvolved radial margin, the MRE of residual disease, if present, was {<=}10 mm in 97.4% (95% confidence interval 91.6-99.5) of cases. Larger MRE measurements were significantly associated with an involved margin (P<.001), tumor size >30 mm (P=.03), premenopausal status (P=.03), and negative progesterone receptor status (P=.05). Conclusions: A clinical target volume margin of 10 mm would encompass microscopic residual disease in >90% of women potentially eligible for PBRT after WLE with noninvolved resection margins.

  15. Targeted Tumor Therapy Based on Nanodiamonds Decorated with Doxorubicin and Folic Acid.

    Science.gov (United States)

    Ryu, Tae-Kyung; Baek, Seung Woon; Lee, Gyoung-Ja; Rhee, Chang-Kyu; Choi, Sung-Wook

    2017-02-01

    The fabrication of nanodiamond (ND)-based drug carriers for tumor-targeted drug delivery is described. The ND clusters with an average size of 52.84 nm are fabricated using a simple fluidic device combined with a precipitation method and then conjugated with folic acid (FA) and doxorubicin (Dox) via carbodiimide chemistry to obtain FA/Dox-modified ND (FA/Dox-ND) clusters. Cell culture experiments revealed that KB (folate receptor-positive) cells are preferentially ablated by FA/Dox-ND clusters compared to A549 (folate receptor-negative) cells. In vivo results revealed that FA/Dox-ND clusters are specifically accumulated in tumor tissues after intravenous injection into tumor-bearing mice, effectively reducing the volume of tumor. Based on these results, this study suggests that FA/Dox-ND clusters can be a good candidate as tumor-targeted nanovehicles for delivery of antitumor drug. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Introducing a simple method of maxillary sinus volume assessment based on linear dimensions.

    Science.gov (United States)

    Przystańska, Agnieszka; Kulczyk, Tomasz; Rewekant, Artur; Sroka, Alicja; Jończyk-Potoczna, Katarzyna; Lorkiewicz-Muszyńska, Dorota; Gawriołek, Krzysztof; Czajka-Jakubowska, Agata

    2018-01-01

    Measuring sinus volume in a general practice clinic is a complex and time-consuming procedure, requiring experience in the use of radiological methods In the presented research, the automatically estimated maxillary sinus volume was compared with maxillary sinus volume assessed with mathematical formulas used to calculate the volume of spheres and pyramids. The starting point for the statistical analysis were specific measurements of the sinuses. We wanted to discover which geometric shape has the volume that is nearest to the automatically estimated volume. The study was performed using samples of CT scans of pediatric patients age 1-17. The dimensions (maximal width, maximal height, maximal length) were used for manual calculations. For the automatic volume calculation, the CT Image Segmentation algorithm (Syngo Via for Oncology, Siemens) was used. Pearson's correlation coefficient was applied to analyse the interrelationship between automatically and manually calculated volume of maxillary sinus. It was statistically established that the "sphere", "pyramid" and "mean" manually calculated maxillary sinus volume were accurate and strongly correlated with the automatically estimated maxillary sinus volume. The volume of the sphere corresponds better with the automatic measurements than the volume of the pyramid. The variations are significant and they were made reliable with the application of a statistical test. It is quick and easy to calculate the maxillary sinus volume based on its linear dimensions instead of applying advanced software. The manual method for maxillary sinus volume calculation requires three linear measurements of the sinus (length, width, and height) and can be recommended if the automatically estimated volume cannot be obtained. Copyright © 2017 Elsevier GmbH. All rights reserved.

  17. Lung lesion doubling times: values and variability based on method of volume determination

    International Nuclear Information System (INIS)

    Eisenbud Quint, Leslie; Cheng, Joan; Schipper, Matthew; Chang, Andrew C.; Kalemkerian, Gregory

    2008-01-01

    Purpose: To determine doubling times (DTs) of lung lesions based on volumetric measurements from thin-section CT imaging. Methods: Previously untreated patients with ≥ two thin-section CT scans showing a focal lung lesion were identified. Lesion volumes were derived using direct volume measurements and volume calculations based on lesion area and diameter. Growth rates (GRs) were compared by tissue diagnosis and measurement technique. Results: 54 lesions were evaluated including 8 benign lesions, 10 metastases, 3 lymphomas, 15 adenocarcinomas, 11 squamous carcinomas, and 7 miscellaneous lung cancers. Using direct volume measurements, median DTs were 453, 111, 15, 181, 139 and 137 days, respectively. Lung cancer DTs ranged from 23-2239 days. There were no significant differences in GRs among the different lesion types. There was considerable variability among GRs using different volume determination methods. Conclusions: Lung cancer doubling times showed a substantial range, and different volume determination methods gave considerably different DTs

  18. Extension of Local Disease in Nasopharyngeal Carcinoma Detected by Magnetic Resonance Imaging: Improvement of Clinical Target Volume Delineation

    International Nuclear Information System (INIS)

    Liang Shaobo; Sun Ying; Liu Lizhi; Chen Yong; Chen Lei; Mao Yanping; Tang Linglong; Tian Li; Lin Aihua; Liu Mengzhong; Li Li; Ma Jun

    2009-01-01

    Purpose: To define by MRI the local extension patterns in patients presenting with nasopharyngeal carcinoma (NPC) and to improve clinical target volume delineation. Methods and Materials: Consecutive patients (N = 943) with newly diagnosed and untreated NPC were included in this study. All patients underwent MRI of the nasopharynx and neck, which was reviewed by two radiologists. Results: According to the incidence rates of tumor invasion, the anatomic sites surrounding the nasopharynx were initially classified into three risk grades: high risk (≥ 35%), medium risk (≥ 5-35%), and low risk (< 5%). Incidence rates of tumor invasion into anatomic sites at medium risk were increased, reaching 55.2%, when adjacent high-risk anatomic sites were involved. However, the rates were substantially lower, mostly < 10%, when adjacent high-risk sites were not involved. The incidence rates of concurrent tumor invasion into bilateral sites were < 10%, except in the case of prevertebral muscle involvement (13.1%). Among the 178 incidences of cavernous sinus invasion, there were often two or more simultaneous infiltration routes (60.6%); when only one route was involved, the foramen ovale was the most common (26.4%). Conclusions: In patients presenting with NPC, local disease spreads stepwise from proximal sites to more distal sites. Tumors extend quickly through privileged pathways such as neural foramina. The anatomic sites surrounding the nasopharynx are at low risk of concurrent bilateral tumor invasion. Selective radiotherapy of the local disease in NPC may be feasible.

  19. Global Calibration of Multiple Cameras Based on Sphere Targets

    Directory of Open Access Journals (Sweden)

    Junhua Sun

    2016-01-01

    Full Text Available Global calibration methods for multi-camera system are critical to the accuracy of vision measurement. Proposed in this paper is such a method based on several groups of sphere targets and a precision auxiliary camera. Each camera to be calibrated observes a group of spheres (at least three, while the auxiliary camera observes all the spheres. The global calibration can be achieved after each camera reconstructs the sphere centers in its field of view. In the process of reconstructing a sphere center, a parameter equation is used to describe the sphere projection model. Theoretical analysis and computer simulation are carried out to analyze the factors that affect the calibration accuracy. Simulation results show that the parameter equation can largely improve the reconstruction accuracy. In the experiments, a two-camera system calibrated by our method is used to measure a distance about 578 mm, and the root mean squared error is within 0.14 mm. Furthermore, the experiments indicate that the method has simple operation and good flexibility, especially for the onsite multiple cameras without common field of view.

  20. High Performance GPU-Based Fourier Volume Rendering

    Directory of Open Access Journals (Sweden)

    Marwan Abdellah

    2015-01-01

    Full Text Available Fourier volume rendering (FVR is a significant visualization technique that has been used widely in digital radiography. As a result of its O(N2log⁡N time complexity, it provides a faster alternative to spatial domain volume rendering algorithms that are O(N3 computationally complex. Relying on the Fourier projection-slice theorem, this technique operates on the spectral representation of a 3D volume instead of processing its spatial representation to generate attenuation-only projections that look like X-ray radiographs. Due to the rapid evolution of its underlying architecture, the graphics processing unit (GPU became an attractive competent platform that can deliver giant computational raw power compared to the central processing unit (CPU on a per-dollar-basis. The introduction of the compute unified device architecture (CUDA technology enables embarrassingly-parallel algorithms to run efficiently on CUDA-capable GPU architectures. In this work, a high performance GPU-accelerated implementation of the FVR pipeline on CUDA-enabled GPUs is presented. This proposed implementation can achieve a speed-up of 117x compared to a single-threaded hybrid implementation that uses the CPU and GPU together by taking advantage of executing the rendering pipeline entirely on recent GPU architectures.

  1. High Performance GPU-Based Fourier Volume Rendering.

    Science.gov (United States)

    Abdellah, Marwan; Eldeib, Ayman; Sharawi, Amr

    2015-01-01

    Fourier volume rendering (FVR) is a significant visualization technique that has been used widely in digital radiography. As a result of its (N (2)log⁡N) time complexity, it provides a faster alternative to spatial domain volume rendering algorithms that are (N (3)) computationally complex. Relying on the Fourier projection-slice theorem, this technique operates on the spectral representation of a 3D volume instead of processing its spatial representation to generate attenuation-only projections that look like X-ray radiographs. Due to the rapid evolution of its underlying architecture, the graphics processing unit (GPU) became an attractive competent platform that can deliver giant computational raw power compared to the central processing unit (CPU) on a per-dollar-basis. The introduction of the compute unified device architecture (CUDA) technology enables embarrassingly-parallel algorithms to run efficiently on CUDA-capable GPU architectures. In this work, a high performance GPU-accelerated implementation of the FVR pipeline on CUDA-enabled GPUs is presented. This proposed implementation can achieve a speed-up of 117x compared to a single-threaded hybrid implementation that uses the CPU and GPU together by taking advantage of executing the rendering pipeline entirely on recent GPU architectures.

  2. Using four‐dimensional computed tomography images to optimize the internal target volume when using volume‐modulated arc therapy to treat moving targets

    Science.gov (United States)

    Yakoumakis, Nikolaos; Winey, Brian; Killoran, Joseph; Mayo, Charles; Niedermayr, Thomas; Panayiotakis, George; Lingos, Tania; Court, Laurence

    2012-01-01

    In this work we used 4D dose calculations, which include the effects of shape deformations, to investigate an alternative approach to creating the ITV. We hypothesized that instead of needing images from all the breathing phases in the 4D CT dataset to create the outer envelope used for treatment planning, it is possible to exclude images from the phases closest to the inhale phase. We used 4D CT images from 10 patients with lung cancer. For each patient, we drew a gross tumor volume on the exhale‐phase image and propagated this to the images from other phases in the 4D CT dataset using commercial image registration software. We created four different ITVs using the N phases closest to the exhale phase (where N=10, 8, 7, 6). For each ITV contour, we created a volume‐modulated arc therapy plan on the exhale‐phase CT and normalized it so that the prescribed dose covered at least 95% of the ITV. Each plan was applied to CT images from each CT phase (phases 1–10), and the calculated doses were then mapped to the exhale phase using deformable registration. The effect of the motion was quantified using the dose to 95% of the target on the exhale phase (D95) and tumor control probability. For the three‐dimensional and 4D dose calculations of the plan where N=10, differences in the D95 value varied from 3% to 14%, with an average difference of 7%. For 9 of the 10 patients, the reduction in D95 was less than 5% if eight phases were used to create the ITV. For three of the 10 patients, the reduction in the D95 was less than 5% if seven phases were used to create the ITV. We were unsuccessful in creating a general rule that could be used to create the ITV. Some reduction (8/10 phases) was possible for most, but not all, of the patients, and the ITV reduction was small. PACS number: 87.55.D‐ PMID:23149778

  3. Variable epitope library-based vaccines: shooting moving targets.

    Science.gov (United States)

    Pedroza-Roldan, Cesar; Charles-Niño, Claudia; Saavedra, Rafael; Govezensky, Tzipe; Vaca, Luis; Avaniss-Aghajani, Eric; Gevorkian, Goar; Manoutcharian, Karen

    2009-12-01

    While the antigenic variability is the major obstacle for developing vaccines against antigenically variable pathogens (AVPs) and cancer, this issue is not addressed adequately in current vaccine efforts. We developed a novel variable epitope library (VEL)-based vaccine strategy using immunogens carrying a mixture of thousands of variants of a single epitope. In this proof-of-concept study, we used an immunodominant HIV-1-derived CD8+ cytotoxic T-lymphocyte (CTL) epitope as a model antigen to construct immunogens in the form of plasmid DNA and recombinant M13 bacteriophages. We generated combinatorial libraries expressing epitope variants with random amino acid substitutions at 2-5 amino acid positions within the epitope. Mice immunized with these immunogens developed epitope-specific CD8+ IFN-gamma+ T-cell responses that recognized more than 50% of heavily mutated variants of wild-type epitope, as demonstrated in T-cell proliferation assays and FACS analysis. Strikingly, these potent and broad epitope-specific immune responses were long lasting: after 12 months of priming, epitope variants were recognized by CD8+ cells and effector memory T cells were induced. In addition, we showed, for the first time, the inhibition of T-cell responses at the molecular level by immune interference: the mice primed with wild-type epitope and 8 or 12 months later immunized with VELs, were not able to recognize variant epitopes efficiently. These data may give a mechanistic explanation for the failure of recent HIV vaccine trials as well as highlight specific hurdles in current molecular vaccine efforts targeting other important antigenically variable pathogens and diseases. These findings suggest that the VEL-based strategy for immunogen construction can be used as a reliable technological platform for the generation of vaccines against AVPs and cancer, and contribute to better understanding complex host-pathogen interactions.

  4. Semantics based approach for analyzing disease-target associations.

    Science.gov (United States)

    Kaalia, Rama; Ghosh, Indira

    2016-08-01

    A complex disease is caused by heterogeneous biological interactions between genes and their products along with the influence of environmental factors. There have been many attempts for understanding the cause of these diseases using experimental, statistical and computational methods. In the present work the objective is to address the challenge of representation and integration of information from heterogeneous biomedical aspects of a complex disease using semantics based approach. Semantic web technology is used to design Disease Association Ontology (DAO-db) for representation and integration of disease associated information with diabetes as the case study. The functional associations of disease genes are integrated using RDF graphs of DAO-db. Three semantic web based scoring algorithms (PageRank, HITS (Hyperlink Induced Topic Search) and HITS with semantic weights) are used to score the gene nodes on the basis of their functional interactions in the graph. Disease Association Ontology for Diabetes (DAO-db) provides a standard ontology-driven platform for describing genes, proteins, pathways involved in diabetes and for integrating functional associations from various interaction levels (gene-disease, gene-pathway, gene-function, gene-cellular component and protein-protein interactions). An automatic instance loader module is also developed in present work that helps in adding instances to DAO-db on a large scale. Our ontology provides a framework for querying and analyzing the disease associated information in the form of RDF graphs. The above developed methodology is used to predict novel potential targets involved in diabetes disease from the long list of loose (statistically associated) gene-disease associations. Copyright © 2016 Elsevier Inc. All rights reserved.

  5. Polysaccharide-based Noncovalent Assembly for Targeted Delivery of Taxol

    Science.gov (United States)

    Yang, Yang; Zhang, Ying-Ming; Chen, Yong; Chen, Jia-Tong; Liu, Yu

    2016-01-01

    The construction of synthetic straightforward, biocompatible and biodegradable targeted drug delivery system with fluorescent tracking abilities, high anticancer activities and low side effects is still a challenge in the field of biochemistry and material chemistry. In this work, we constructed targeted paclitaxel (Taxol) delivery nanoparticles composed of permethyl-β-cyclodextrin modified hyaluronic acid (HApCD) and porphyrin modified paclitaxel prodrug (PorTaxol), through host-guest and amphiphilic interactions. The obtained nanoparticles (HATXP) were biocompatible and enzymatic biodegradable due to their hydrophilic hyaluronic acid (HA) shell and hydrophobic Taxol core, and exhibited specific targeting internalization into cancer cells via HA receptor mediated endocytosis effects. The cytotoxicity experiments showed that the HATXP exhibited similar anticancer activities to, but much lower side effects than commercial anticancer drug Taxol. The present work would provide a platform for targeted paclitaxel drug delivery and a general protocol for the design of advanced multifunctional nanoscale biomaterials for targeted drug/gene delivery.

  6. Target volume delineation for head and neck cancer intensity-modulated radiotherapy; Delineation des volumes cibles des cancers des voies aerodigestives superieures en radiotherapie conformationnelle avec modulation d'intensite

    Energy Technology Data Exchange (ETDEWEB)

    Lapeyre, M.; Toledano, I.; Bourry, N. [Departement de radiotherapie, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France); Bailly, C. [Unite de radiodiagnostic, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France); Cachin, F. [Unite de medecine nucleaire, centre Jean-Perrin, 58, rue Montalembert, BP 5026, 63011 Clermont-Ferrand cedex 1 (France)

    2011-10-15

    This article describes the determination and the delineation of the target volumes for head-and-neck cancers treated with intensity-modulated radiotherapy (IMRT). The delineation of the clinical target volumes (CTV) on the computerized tomography scanner (CT scan) requires a rigorous methodology due to the complexity of head-and-neck anatomy. The clinical examination with a sketch of pretreatment tumour extension, the surgical and pathological reports and the adequate images (CT scan, magnetic resonance imaging and fluorodeoxyglucose positron emission tomography) are necessary for the delineation. The target volumes depend on the overall strategy: sequential IMRT or simultaneous integrated boost-IMRT (SIB-IMRT). The concept of selectivity of the potential subclinical disease near the primary tumor and the selection of neck nodal targets are described according to the recommendations and the literature. The planing target volume (PTV), mainly reflecting setup errors (random and systematic), results from a uniform 4-5 mm expansion around the CTV. We propose the successive delineation of: (1) the gross volume tumour (GTV); (2) the 'high risk' CTV1 around the GTV or including the postoperative tumour bed in case of positive margins or nodal extra-capsular spread (65-70 Gy in 30-35 fractions); (3) the CTV2 'intermediate risk' around the CTV1 for SIB-IMRT (59-63 Gy in 30-35 fractions); (4) the 'low-risk' CTV3 (54-56 Gy in 30-35 fractions); (5) the PTVs. (authors)

  7. Delineation of the primary tumour Clinical Target Volumes (CTV-P) in laryngeal, hypopharyngeal, oropharyngeal and oral cavity squamous cell carcinoma

    DEFF Research Database (Denmark)

    Grégoire, Vincent; Evans, Mererid; Le, Quynh-Thu

    2018-01-01

    PURPOSE: Few studies have reported large inter-observer variations in target volume selection and delineation in patients treated with radiotherapy for head and neck squamous cell carcinoma. Consensus guidelines have been published for the neck nodes (see Grégoire et al., 2003, 2014), but such re...

  8. Dosimetric effect of multileaf collimator leaf width in intensity-modulated radiotherapy delivery techniques for small- and large-volume targets

    International Nuclear Information System (INIS)

    Yoganathan, S.A.; Mani, Karthick Raj; Maria Das, K.J.; Agarwal, Arpita; Kumar, Shaleen

    2011-01-01

    The purpose of this study was to evaluate the dosimetric effect of the leaf width of a multileaf collimator (MLC) in intensity-modulated radiotherapy (IMRT) delivery techniques for small- and large-volume targets. We retrospectively selected previously treated 5 intracranial and 5 head-neck patients for this study to represent small- (range, 18.37-72.75 cc; mean, 42.99 cc) and large-volume (range, 312.31-472.84 cc; mean, 361.14 cc) targets. A 6-MV photon beam data was configured for Brianlab m3 (3 mm), Varian Millennium 120 (5 mm) and Millennium 80 (10 mm) MLCs in the Eclipse treatment-planning system. Sliding window and step-shoot IMRT plans were generated for intracranial patients using all the above-mentioned MLCs; but due to the field size limitation of Brainlab MLC, we used only 5-mm and 10-mm MLCs in the head-and-neck patients. Target conformity, dose to the critical organs and dose to normal tissues were recorded and evaluated. Although the 3-mm MLC resulted in better target conformity (mean difference of 7.7% over 5-mm MLC and 12.7% over 10-mm MLC) over other MLCs for small-volume targets, it increased the total monitor units of the plans. No appreciable differences in terms of target conformity, organ at risk and normal-tissue sparing were observed between the 5-mm and 10-mm MLCs for large-volume targets. The effect of MLC leaf width was not quantifiably different in sliding window and step and shoot techniques. In addition, we observed that there was no additional benefit to the sliding-window (SW) technique when compared to the step-shoot (SS) technique as a result of reduction of MLC leaf width. (author)

  9. Strategies for Small Volume Resuscitation: Hyperosmotic-Hyperoncotic Solutions, Hemoglobin Based Oxygen Carriers and Closed-Loop Resuscitation

    Science.gov (United States)

    Kramer, George C.; Wade, Charles E.; Dubick, Michael A.; Atkins, James L.

    2004-01-01

    Introduction: Logistic constraints on combat casualty care preclude traditional resuscitation strategies which can require volumes and weights 3 fold or greater than hemorrhaged volume. We present a review of quantitative analyses of clinical and animal data on small volume strategies using 1) hypertonic-hyperosmotic solutions (HHS); 2) hemoglobin based oxygen carriers (HBOCs) and 3) closed-loop infusion regimens.Methods and Results: Literature searches and recent queries to industry and academic researchers have allowed us to evaluate the record of 81 human HHS studies (12 trauma trials), 19 human HBOCs studies (3trauma trials) and two clinical studies of closed-loop resuscitation.There are several hundreds animal studies and at least 82 clinical trials and reports evaluating small volume7.2%-7.5% hypertonic saline (HS) most often combined with colloids, e.g., dextran (HSD) or hetastarch(HSS). HSD and HSS data has been published for 1,108 and 392 patients, respectively. Human studies have documented volume sparing and hemodynamic improvements. Meta-analyses suggest improved survival for hypotensive trauma patients treated with HSD with significant reductions in mortality found for patients with blood pressure blood use and lower mortality compared to historic controls of patients refusing blood. Transfusion reductions with HBOC use have been modest. Two HBOCs (Hemopure and Polyheme) are now in new or planned large-scale multicenter prehospital trials of trauma treatment. A new implementation of small volume resuscitation is closed-loop resuscitation (CLR), which employs microprocessors to titrate just enough fluid to reach a physiologic target . Animal studies suggest less risk of rebleeding in uncontrolled hemorrhage and a reduction in fluid needs with CLR. The first clinical application of CLR was treatment of burn shock and the US Army. Conclusions: Independently sponsored civilian trauma trials and clinical evaluations in operational combat conditions of

  10. A New Brain Positron Emission Tomography Scanner With Semiconductor Detectors for Target Volume Delineation and Radiotherapy Treatment Planning in Patients With Nasopharyngeal Carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Katoh, Norio, E-mail: noriwokatoh@med.hokudai.ac.jp [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Yasuda, Koichi [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Shiga, Tohru [Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Hasegawa, Masakazu; Onimaru, Rikiya; Shimizu, Shinichi [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Bengua, Gerard; Ishikawa, Masayori [Department of Medical Physics, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Tamaki, Nagara [Department of Nuclear Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan); Shirato, Hiroki [Department of Radiation Medicine, Hokkaido University Graduate School of Medicine, Sapporo (Japan)

    2012-03-15

    Purpose: We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PET{sub CONV}WB) versus the new brain (BR) PET system using semiconductor detectors (PET{sub NEW}BR). Methods and Materials: Twelve patients with NPC were enrolled in this study. [{sup 18}F]Fluorodeoxyglucose-PET images were acquired using both the PET{sub NEW}BR and the PET{sub CONV}WB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PET{sub CONV}WB and PET{sub NEW}BR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PET{sub CONV}WB (GTV{sub CONV}) images or PET{sub NEW}BR (GTV{sub NEW}) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. Results: The average absolute volume ({+-}standard deviation [SD]) of GTV{sub NEW} was 15.7 ml ({+-}9.9) ml, and that of GTV{sub CONV} was 34.0 ({+-}20.5) ml. The average GTV{sub NEW} was significantly smaller than that of GTV{sub CONV} (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN{sub NEW}) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Conclusion: Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy

  11. A new brain positron emission tomography scanner with semiconductor detectors for target volume delineation and radiotherapy treatment planning in patients with nasopharyngeal carcinoma.

    Science.gov (United States)

    Katoh, Norio; Yasuda, Koichi; Shiga, Tohru; Hasegawa, Masakazu; Onimaru, Rikiya; Shimizu, Shinichi; Bengua, Gerard; Ishikawa, Masayori; Tamaki, Nagara; Shirato, Hiroki

    2012-03-15

    We compared two treatment planning methods for stereotactic boost for treating nasopharyngeal carcinoma (NPC): the use of conventional whole-body bismuth germanate (BGO) scintillator positron emission tomography (PET(CONV)WB) versus the new brain (BR) PET system using semiconductor detectors (PET(NEW)BR). Twelve patients with NPC were enrolled in this study. [(18)F]Fluorodeoxyglucose-PET images were acquired using both the PET(NEW)BR and the PET(CONV)WB system on the same day. Computed tomography (CT) and two PET data sets were transferred to a treatment planning system, and the PET(CONV)WB and PET(NEW)BR images were coregistered with the same set of CT images. Window width and level values for all PET images were fixed at 3000 and 300, respectively. The gross tumor volume (GTV) was visually delineated on PET images by using either PET(CONV)WB (GTV(CONV)) images or PET(NEW)BR (GTV(NEW)) images. Assuming a stereotactic radiotherapy boost of 7 ports, the prescribed dose delivered to 95% of the planning target volume (PTV) was set to 2000 cGy in 4 fractions. The average absolute volume (±standard deviation [SD]) of GTV(NEW) was 15.7 ml (±9.9) ml, and that of GTV(CONV) was 34.0 (±20.5) ml. The average GTV(NEW) was significantly smaller than that of GTV(CONV) (p = 0.0006). There was no statistically significant difference between the maximum dose (p = 0.0585) and the mean dose (p = 0.2748) of PTV. The radiotherapy treatment plan based on the new gross tumor volume (PLAN(NEW)) significantly reduced maximum doses to the cerebrum and cerebellum (p = 0.0418) and to brain stem (p = 0.0041). Results of the present study suggest that the new brain PET system using semiconductor detectors can provide more accurate tumor delineation than the conventional whole-body BGO PET system and may be an important tool for functional and molecular radiotherapy treatment planning. Copyright © 2012 Elsevier Inc. All rights reserved.

  12. GPU-based multi-volume ray casting within VTK for medical applications.

    Science.gov (United States)

    Bozorgi, Mohammadmehdi; Lindseth, Frank

    2015-03-01

    Multi-volume visualization is important for displaying relevant information in multimodal or multitemporal medical imaging studies. The main objective with the current study was to develop an efficient GPU-based multi-volume ray caster (MVRC) and validate the proposed visualization system in the context of image-guided surgical navigation. Ray casting can produce high-quality 2D images from 3D volume data but the method is computationally demanding, especially when multiple volumes are involved, so a parallel GPU version has been implemented. In the proposed MVRC, imaginary rays are sent through the volumes (one ray for each pixel in the view), and at equal and short intervals along the rays, samples are collected from each volume. Samples from all the volumes are composited using front to back α-blending. Since all the rays can be processed simultaneously, the MVRC was implemented in parallel on the GPU to achieve acceptable interactive frame rates. The method is fully integrated within the visualization toolkit (VTK) pipeline with the ability to apply different operations (e.g., transformations, clipping, and cropping) on each volume separately. The implemented method is cross-platform (Windows, Linux and Mac OSX) and runs on different graphics card (NVidia and AMD). The speed of the MVRC was tested with one to five volumes of varying sizes: 128(3), 256(3), and 512(3). A Tesla C2070 GPU was used, and the output image size was 600 × 600 pixels. The original VTK single-volume ray caster and the MVRC were compared when rendering only one volume. The multi-volume rendering system achieved an interactive frame rate (> 15 fps) when rendering five small volumes (128 (3) voxels), four medium-sized volumes (256(3) voxels), and two large volumes (512(3) voxels). When rendering single volumes, the frame rate of the MVRC was comparable to the original VTK ray caster for small and medium-sized datasets but was approximately 3 frames per second slower for large datasets. The

  13. Vehicle target detection method based on the average optical flow

    Science.gov (United States)

    Ma, J. Y.; Jie, F. R.; Hu, Y. J.

    2017-07-01

    Moving target detection in image sequence for dynamic scene is an important research topic in the field of computer vision. Block projection and matching are utilized for global motion estimation. Then, the background image is compensated applying the estimated motion parameters so as to stabilize the image sequence. Consequently, background subtraction is employed in the stabilized image sequence to extract moving targets. Finally, divide the difference image into uniform grids and average optical flow is employed for motion analysis. Experiment tests show that the proposed average optical flow method can efficiently extract the vehicle targets from dynamic scene meanwhile decreasing the false alarm.

  14. Observer variation in target volume delineation of lung cancer related to radiation oncologist-computer interaction: A 'Big Brother' evaluation

    International Nuclear Information System (INIS)

    Steenbakkers, Roel J.H.M.; Duppen, Joop C.; Fitton, Isabelle; Deurloo, Kirsten E.I.; Zijp, Lambert; Uitterhoeve, Apollonia L.J.; Rodrigus, Patrick T.R.; Kramer, Gijsbert W.P.; Bussink, Johan; Jaeger, Katrien De; Belderbos, Jose S.A.; Hart, Augustinus A.M.; Nowak, Peter J.C.M.; Herk, Marcel van; Rasch, Coen R.N.

    2005-01-01

    Background and purpose: To evaluate the process of target volume delineation in lung cancer for optimization of imaging, delineation protocol and delineation software. Patients and methods: Eleven radiation oncologists (observers) from five different institutions delineated the Gross Tumor Volume (GTV) including positive lymph nodes of 22 lung cancer patients (stages I-IIIB) on CT only. All radiation oncologist-computer interactions were recorded with a tool called 'Big Brother'. For each radiation oncologist and patient the following issues were analyzed: delineation time, number of delineated points and corrections, zoom levels, level and window (L/W) settings, CT slice changes, use of side windows (coronal and sagittal) and software button use. Results: The mean delineation time per GTV was 16 min (SD 10 min). The mean delineation time for lymph node positive patients was on average 3 min larger (P=0.02) than for lymph node negative patients. Many corrections (55%) were due to L/W change (e.g. delineating in mediastinum L/W and then correcting in lung L/W). For the lymph node region, a relatively large number of corrections was found (3.7 corr/cm 2 ), indicating that it was difficult to delineate lymph nodes. For the tumor-atelectasis region, a relative small number of corrections was found (1.0 corr/cm 2 ), indicating that including or excluding atelectasis into the GTV was a clinical decision. Inappropriate use of L/W settings was frequently found (e.g. 46% of all delineated points in the tumor-lung region were delineated in mediastinum L/W settings). Despite a large observer variation in cranial and caudal direction of 0.72 cm (1 SD), the coronal and sagittal side windows were not used in 45 and 60% of the cases, respectively. For the more difficult cases, observer variation was smaller when the coronal and sagittal side windows were used. Conclusions: With the 'Big Brother' tool a method was developed to trace the delineation process. The differences between

  15. An assessment of interfractional uterine and cervical motion: Implications for radiotherapy target volume definition in gynaecological cancer

    International Nuclear Information System (INIS)

    Taylor, Alexandra; Powell, Melanie E.B.

    2008-01-01

    Purpose: To assess interfractional movement of the uterus and cervix in patients with gynaecological cancer to aid selection of the internal margin for radiotherapy target volumes. Methods and materials: Thirty-three patients with gynaecological cancer had an MRI scan performed on two consecutive days. The two sets of T2-weighted axial images were co-registered, and the uterus and cervix outlined on each scan. Points were identified on the anterior uterine body (Point U), posterior cervix (Point C) and upper vagina (Point V). The displacement of each point in the antero-posterior (AP), supero-inferior (SI) and lateral directions between the two scans was measured. The changes in point position and uterine body angle were correlated with bladder volume and rectal diameter. Results: The mean difference (±1SD) in Point U position was 7 mm (±9.0) in the AP direction, 7.1 mm (±6.8) SI and 0.8 mm (±1.3) laterally. Mean Point C displacement was 4.1 mm (±4.4) SI, 2.7 mm (±2.8) AP, 0.3 (±0.8) laterally, and Point V was 2.6 mm (±3.0) AP and 0.3 mm (±1.0) laterally. There was correlation for uterine SI movement in relation to bladder filling, and for cervical and vaginal AP movement in relation to rectal filling. Conclusion: Large movements of the uterus can occur, particularly in the superior-inferior and anterior-posterior directions, but cervical displacement is less marked. Rectal filling may affect cervical position, while bladder filling has more impact on uterine body position, highlighting the need for specific instructions on bladder and rectal filling for treatment. We propose an asymmetrical margin with CTV-PTV expansion of the uterus, cervix and upper vagina of 15 mm AP, 15 mm SI and 7 mm laterally and expansion of the nodal regions and parametria by 7 mm in all directions

  16. Methods for Reducing Normal Tissue Complication Probabilities in Oropharyngeal Cancer: Dose Reduction or Planning Target Volume Elimination

    Energy Technology Data Exchange (ETDEWEB)

    Samuels, Stuart E.; Eisbruch, Avraham; Vineberg, Karen; Lee, Jae; Lee, Choonik; Matuszak, Martha M.; Ten Haken, Randall K.; Brock, Kristy K., E-mail: kbrock@med.umich.edu

    2016-11-01

    Purpose: Strategies to reduce the toxicities of head and neck radiation (ie, dysphagia [difficulty swallowing] and xerostomia [dry mouth]) are currently underway. However, the predicted benefit of dose and planning target volume (PTV) reduction strategies is unknown. The purpose of the present study was to compare the normal tissue complication probabilities (NTCP) for swallowing and salivary structures in standard plans (70 Gy [P70]), dose-reduced plans (60 Gy [P60]), and plans eliminating the PTV margin. Methods and Materials: A total of 38 oropharyngeal cancer (OPC) plans were analyzed. Standard organ-sparing volumetric modulated arc therapy plans (P70) were created and then modified by eliminating the PTVs and treating the clinical tumor volumes (CTVs) only (C70) or maintaining the PTV but reducing the dose to 60 Gy (P60). NTCP dose models for the pharyngeal constrictors, glottis/supraglottic larynx, parotid glands (PGs), and submandibular glands (SMGs) were analyzed. The minimal clinically important benefit was defined as a mean change in NTCP of >5%. The P70 NTCP thresholds and overlap percentages of the organs at risk with the PTVs (56-59 Gy, vPTV{sub 56}) were evaluated to identify the predictors for NTCP improvement. Results: With the P60 plans, only the ipsilateral PG (iPG) benefited (23.9% vs 16.2%; P<.01). With the C70 plans, only the iPG (23.9% vs 17.5%; P<.01) and contralateral SMG (cSMG) (NTCP 32.1% vs 22.9%; P<.01) benefited. An iPG NTCP threshold of 20% and 30% predicted NTCP benefits for the P60 and C70 plans, respectively (P<.001). A cSMG NTCP threshold of 30% predicted for an NTCP benefit with the C70 plans (P<.001). Furthermore, for the iPG, a vPTV{sub 56} >13% predicted benefit with P60 (P<.001) and C70 (P=.002). For the cSMG, a vPTV{sub 56} >22% predicted benefit with C70 (P<.01). Conclusions: PTV elimination and dose-reduction lowered the NTCP of the iPG, and PTV elimination lowered the NTCP of the cSMG. NTCP thresholds and the

  17. An active target for the accelerator-based transmutation system

    Energy Technology Data Exchange (ETDEWEB)

    Grebyonkin, K.F. [Institute of Technical Physics, Chelyabinsk (Russian Federation)

    1995-10-01

    Consideration is given to the possibility of radical reduction in power requirements to the proton accelerator of the electronuclear reactor due to neutron multiplication both in the blanket and the target of an active material. The target is supposed to have the fast-neutron spectrum, and the blanket-the thermal one. The blanket and the target are separated by the thermal neutrons absorber, which is responsible for the neutron decoupling of the active target and blanket. Also made are preliminary estimations which illustrate that the realization of the idea under consideration can lead to significant reduction in power requirements to the proton beam and, hence considerably improve economic characteristics of the electronuclear reactor.

  18. Risk-Based Treatment Targets for Onsite Non-Potable Water ...

    Science.gov (United States)

    This presentation presents risk-based enteric pathogen log reduction targets for non-potable and potable uses of a variety of alternative source waters (i.e., municipal wastewater, locally-collected greywater, rainwater, and stormwater). A probabilistic, forward Quantitative Microbial Risk Assessment (QMRA) was used to derive the pathogen log10 reduction targets (LRTs) that corresponded with an infection risk of either 10-4 per person per year (ppy) or 10-2 ppy. The QMRA accounted for variation in pathogen concentration and sporadic pathogen occurrence (when data were available) in source waters for reference pathogens Rotavirus, Adenovirus, Norovirus, Campylobacter spp., Salmonella spp., Giardia spp., and Cryptosporidium spp.. Non-potable uses included indoor use (for toilet flushing and clothes washing) with accidental ingestion of treated non-potable water (or cross connection with potable water), and unrestricted irrigation for outdoor use. Various exposure scenarios captured the uncertainty from key inputs, i.e., the pathogen concentration in source water; the volume of water ingested; and for the indoor use, the frequency of and the fraction of the population exposed to accidental ingestion. Both potable and non-potable uses required pathogen treatment for the selected waters and the LRT was generally greater for potable use than nonpotable indoor use and unrestricted irrigation. The difference in treatment requirements among source waters was driven by th

  19. A volume-based method for denoising on curved surfaces

    KAUST Repository

    Biddle, Harry

    2013-09-01

    We demonstrate a method for removing noise from images or other data on curved surfaces. Our approach relies on in-surface diffusion: we formulate both the Gaussian diffusion and Perona-Malik edge-preserving diffusion equations in a surface-intrinsic way. Using the Closest Point Method, a recent technique for solving partial differential equations (PDEs) on general surfaces, we obtain a very simple algorithm where we merely alternate a time step of the usual Gaussian diffusion (and similarly Perona-Malik) in a small 3D volume containing the surface with an interpolation step. The method uses a closest point function to represent the underlying surface and can treat very general surfaces. Experimental results include image filtering on smooth surfaces, open surfaces, and general triangulated surfaces. © 2013 IEEE.

  20. Tweet-based Target Market Classification Using Ensemble Method

    Directory of Open Access Journals (Sweden)

    Muhammad Adi Khairul Anshary

    2016-09-01

    Full Text Available Target market classification is aimed at focusing marketing activities on the right targets. Classification of target markets can be done through data mining and by utilizing data from social media, e.g. Twitter. The end result of data mining are learning models that can classify new data. Ensemble methods can improve the accuracy of the models and therefore provide better results. In this study, classification of target markets was conducted on a dataset of 3000 tweets in order to extract features. Classification models were constructed to manipulate the training data using two ensemble methods (bagging and boosting. To investigate the effectiveness of the ensemble methods, this study used the CART (classification and regression tree algorithm for comparison. Three categories of consumer goods (computers, mobile phones and cameras and three categories of sentiments (positive, negative and neutral were classified towards three target-market categories. Machine learning was performed using Weka 3.6.9. The results of the test data showed that the bagging method improved the accuracy of CART with 1.9% (to 85.20%. On the other hand, for sentiment classification, the ensemble methods were not successful in increasing the accuracy of CART. The results of this study may be taken into consideration by companies who approach their customers through social media, especially Twitter.

  1. Solar concentrator technology development for space based applications, volume 2

    Science.gov (United States)

    Pintz, A.; Castle, C. H.; Reimer, R. R.

    1992-01-01

    Thermoelectric conversion using a radio-isotope heat source has been used where outer planetary space craft are too far away for absorbing significant solar energy. Solar dynamic power (SDP) conversion is one technology that offers advantages for applications within the inner planet region. Since SDP conversion efficiency can be 2 to 3 times higher than photovoltaic, the collecting surfaces are much reduced in area and therefore lighter. This becomes an advantage in allocating more weight to launched payloads. A second advantage results for low earth orbit applications. The reduced area results in lower drag forces on the spacecraft and requires less reboost propellant to maintain orbit. A third advantage occurs because of the sun-to-shade cycling while in earth orbit. Photovoltaic systems require batteries to store energy for use when in the shade, and battery life for periods of 10 to 15 years is not presently achievable. For these reasons the Solar Dynamics and Thermal Systems Branch at NASA LeRC has funded work in developing SDP systems. The generic SDP system uses a large parabolic solar concentrator to focus solar energy onto a power conversion device. The concentrators are large areas and must therefore be efficient and have low specific weights. Yet these surfaces must be precise and capable of being stowed in a launch vehicle and then deployed and sometimes unfurled in space. There are significant technical challenges in engineering such structures, and considerable investigation has been made to date. This is the second of two volumes reporting on the research done by the Advanced Manufacturing Center at Cleveland State University to assist NASA LeRC in evaluating this technology. This volume includes the appendices of selected data sets, drawings, and procedures. The objective of the grant was to restore the solar concentrator development technology of the 1960s while improving it with advances that have occurred since then. This report summarizes the

  2. Computer-Based Assessments. Information Capsule. Volume 0918

    Science.gov (United States)

    Blazer, Christie

    2010-01-01

    This Information Capsule reviews research conducted on computer-based assessments. Advantages and disadvantages associated with computer-based testing programs are summarized and research on the comparability of computer-based and paper-and-pencil assessments is reviewed. Overall, studies suggest that for most students, there are few if any…

  3. Analysis of parotid gland and target volume variations during the head neck cancer intensity modulated radiation therapy

    International Nuclear Information System (INIS)

    Luo Jingwei; Fu Weihua; Xu Guozhen; Gao Li; Yan Di; Wu Qiuwen

    2006-01-01

    Objective: To study the changes in gross tumor volume (GTV) and parotid gland volume dur- ing intensity modulated radiation therapy (IMRT) for head and neck cancer. Methods: Five patients with head and neck squamous carcinoma were treated by IMRT. Cone beam CT was done every week during the whole course of radiotherapy. All images were fused with cone beam CT pictures and the initial CT pictures. The contouring was on normal parotid gland and gas cavity in each slide of cone beam CT. The changes of parotid gland and gas volume in GTV were calculated. Results: The parotid gland volume decreased, and gas volume in the GTV increased throughout the course of IMRT. At the end of radiotherapy, the parotid gland volume decreased to 90.1%- 52.3% compared with the volume before IMRT, gas cavity volume increased and took up to 3.7%-16.8% of GTV at the beginning of radiotherapy. Conclusion: Normal parotid gland volume and GTV is changed during IMRT in head and neck cancer. Cone beam CT can be used to find these changes which are helpful in carrying out the second IMRT plan. (authors)

  4. Methodological approaches to planar and volumetric scintigraphic imaging of small volume targets with high spatial resolution and sensitivity

    Energy Technology Data Exchange (ETDEWEB)

    Mejia, J.; Galvis-Alonso, O.Y. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Faculdade de Medicina. Dept. de Biologia Molecular], e-mail: mejia_famerp@yahoo.com.br; Braga, J. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Div. de Astrofisica; Correa, R. [Instituto Nacional de Pesquisas Espaciais (INPE), Sao Jose dos Campos, SP (Brazil). Div. de Ciencia Espacial e Atmosferica; Leite, J.P. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Neurologia, Psiquiatria e Psicologia Medica; Simoes, M.V. [Faculdade de Medicina de Sao Jose do Rio Preto (FAMERP), SP (Brazil). Dept. de Clinica Medica

    2009-08-15

    Single-photon emission computed tomography (SPECT) is a non-invasive imaging technique, which provides information reporting the functional states of tissues. SPECT imaging has been used as a diagnostic tool in several human disorders and can be used in animal models of diseases for physiopathological, genomic and drug discovery studies. However, most of the experimental models used in research involve rodents, which are at least one order of magnitude smaller in linear dimensions than man. Consequently, images of targets obtained with conventional gamma-cameras and collimators have poor spatial resolution and statistical quality. We review the methodological approaches developed in recent years in order to obtain images of small targets with good spatial resolution and sensitivity. Multi pinhole, coded mask- and slit-based collimators are presented as alternative approaches to improve image quality. In combination with appropriate decoding algorithms, these collimators permit a significant reduction of the time needed to register the projections used to make 3-D representations of the volumetric distribution of target's radiotracers. Simultaneously, they can be used to minimize artifacts and blurring arising when single pinhole collimators are used. Representation images are presented, which illustrate the use of these collimators. We also comment on the use of coded masks to attain tomographic resolution with a single projection, as discussed by some investigators since their introduction to obtain near-field images. We conclude this review by showing that the use of appropriate hardware and software tools adapted to conventional gamma-cameras can be of great help in obtaining relevant functional information in experiments using small animals. (author)

  5. Methodological approaches to planar and volumetric scintigraphic imaging of small volume targets with high spatial resolution and sensitivity

    International Nuclear Information System (INIS)

    Mejia, J.; Galvis-Alonso, O.Y.; Braga, J.; Correa, R.; Leite, J.P.; Simoes, M.V.

    2009-01-01

    Single-photon emission computed tomography (SPECT) is a non-invasive imaging technique, which provides information reporting the functional states of tissues. SPECT imaging has been used as a diagnostic tool in several human disorders and can be used in animal models of diseases for physiopathological, genomic and drug discovery studies. However, most of the experimental models used in research involve rodents, which are at least one order of magnitude smaller in linear dimensions than man. Consequently, images of targets obtained with conventional gamma-cameras and collimators have poor spatial resolution and statistical quality. We review the methodological approaches developed in recent years in order to obtain images of small targets with good spatial resolution and sensitivity. Multi pinhole, coded mask- and slit-based collimators are presented as alternative approaches to improve image quality. In combination with appropriate decoding algorithms, these collimators permit a significant reduction of the time needed to register the projections used to make 3-D representations of the volumetric distribution of target's radiotracers. Simultaneously, they can be used to minimize artifacts and blurring arising when single pinhole collimators are used. Representation images are presented, which illustrate the use of these collimators. We also comment on the use of coded masks to attain tomographic resolution with a single projection, as discussed by some investigators since their introduction to obtain near-field images. We conclude this review by showing that the use of appropriate hardware and software tools adapted to conventional gamma-cameras can be of great help in obtaining relevant functional information in experiments using small animals. (author)

  6. Proposed Renewable Fuel Standards for 2017, and the Biomass-Based Diesel Volume for 2018

    Science.gov (United States)

    EPA is proposing the volume requirements and associated percentage standards that would apply under the RFS program in calendar years 2016, 2017 and 2018 for cellulosic biofuel, biomass-based diesel, advanced biofuel, and total renewable fuel.

  7. Surrogate Plant Data Base : Volume 2. Appendix C : Facilities Planning Baseline Data

    Science.gov (United States)

    1983-05-01

    This four volume report consists of a data base describing "surrogate" automobile and truck manufacturing plants developed as part of a methodology for evaluating capital investment requirements in new manufacturing facilities to build new fleets of ...

  8. Surrogate Plant Data Base : Volume 4. Appendix E : Medium and Heavy Truck Manufacturing

    Science.gov (United States)

    1983-05-01

    This four volume report consists of a data base describing "surrogate" automobile and truck manufacturing plants developed as part of a methodology for evaluating capital investment requirements in new manufacturing facilities to build new fleets of ...

  9. An enhanced matrix-free edge-based finite volume approach to model structures

    CSIR Research Space (South Africa)

    Suliman, Ridhwaan

    2010-01-01

    Full Text Available This paper presents the formulation, implementation and evaluation of an enhanced matrix free edge-based finite volume approach to model the mechanics of solids undergoing large non-linear deformations. The developed technology is evaluated via...

  10. Transaction-Based Building Controls Framework, Volume 1: Reference Guide

    Energy Technology Data Exchange (ETDEWEB)

    Somasundaram, Sriram [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Pratt, Robert G. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Akyol, Bora A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Fernandez, Nicholas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Foster, Nikolas AF [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Katipamula, Srinivas [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Mayhorn, Ebony T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Somani, Abhishek [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Steckley, Andrew C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Taylor, Zachary T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2014-12-01

    This document proposes a framework concept to achieve the objectives of raising buildings’ efficiency and energy savings potential benefitting building owners and operators. We call it a transaction-based framework, wherein mutually-beneficial and cost-effective market-based transactions can be enabled between multiple players across different domains. Transaction-based building controls are one part of the transactional energy framework. While these controls realize benefits by enabling automatic, market-based intra-building efficiency optimizations, the transactional energy framework provides similar benefits using the same market -based structure, yet on a larger scale and beyond just buildings, to the society at large.

  11. A Well-Clear Volume Based on Time to Entry Point

    Science.gov (United States)

    Narkawicz, Anthony J.; Munoz, Cesar A.; Upchurch, Jason M.; Chamberlain, James P.; Consiglio, Maria C.

    2014-01-01

    A well-clear volume is a key component of NASA's Separation Assurance concept for the integration of UAS in the NAS. This paper proposes a mathematical definition of the well-clear volume that uses, in addition to distance thresholds, a time threshold based on time to entry point (TEP). The mathematical model that results from this definition is more conservative than other candidate definitions of the wellclear volume that are based on range over closure rate and time to closest point of approach.

  12. Identifying problematic drugs based on the characteristics of their targets.

    Science.gov (United States)

    Lopes, Tiago J S; Shoemaker, Jason E; Matsuoka, Yukiko; Kawaoka, Yoshihiro; Kitano, Hiroaki

    2015-01-01

    Identifying promising compounds during the early stages of drug development is a major challenge for both academia and the pharmaceutical industry. The difficulties are even more pronounced when we consider multi-target pharmacology, where the compounds often target more than one protein, or multiple compounds are used together. Here, we address this problem by using machine learning and network analysis to process sequence and interaction data from human proteins to identify promising compounds. We used this strategy to identify properties that make certain proteins more likely to cause harmful effects when targeted; such proteins usually have domains commonly found throughout the human proteome. Additionally, since currently marketed drugs hit multiple targets simultaneously, we combined the information from individual proteins to devise a score that quantifies the likelihood of a compound being harmful to humans. This approach enabled us to distinguish between approved and problematic drugs with an accuracy of 60-70%. Moreover, our approach can be applied as soon as candidate drugs are available, as demonstrated with predictions for more than 5000 experimental drugs. These resources are available at http://sourceforge.net/projects/psin/.

  13. Identifying problematic drugs based on the characteristics of their targets

    Directory of Open Access Journals (Sweden)

    Tiago Jose eDa Silva Lopes

    2015-09-01

    Full Text Available Identifying promising compounds during the early stages of drug development is a major challenge for both academia and the pharmaceutical industry. The difficulties are even more pronounced when we consider multi-target pharmacology, where the compounds often target more than one protein, or multiple compounds are used together. Here, we address this problem by using machine learning and network analysis to process sequence and interaction data from human proteins to identify promising compounds. We used this strategy to identify properties that make certain proteins more likely to cause harmful effects when targeted; such proteins usually have domains commonly found throughout the human proteome. Additionally, since currently marketed drugs hit multiple targets simultaneously, we combined the information from individual proteins to devise a score that quantifies the likelihood of a compound being harmful to humans. This approach enabled us to distinguish between approved and problematic drugs with an accuracy of 60%¬–70%. Moreover, our approach can be applied as soon as candidate drugs are available, as demonstrated with predictions for more than 5000 experimental drugs. These resources are available at http://sourceforge.net/projects/psin/.

  14. Efficient Fourier based Algorithm Development for Airborne Moving Target Indication

    NARCIS (Netherlands)

    Lidicky, L.; Hoogeboom, P.

    2009-01-01

    This paper shows how the signal model that is commonly used as a starting point in multi-channel Space Time Adaptive Processing (STAP) for airborne Moving Target Indication (MTI) formally corresponds to a model that can be derived from a bi-static Synthetic Aperture Radar (SAR) model extended for

  15. On the Use of Generalized Volume Scattering Models for the Improvement of General Polarimetric Model-Based Decomposition

    Directory of Open Access Journals (Sweden)

    Qinghua Xie

    2017-01-01

    Full Text Available Recently, a general polarimetric model-based decomposition framework was proposed by Chen et al., which addresses several well-known limitations in previous decomposition methods and implements a simultaneous full-parameter inversion by using complete polarimetric information. However, it only employs four typical models to characterize the volume scattering component, which limits the parameter inversion performance. To overcome this issue, this paper presents two general polarimetric model-based decomposition methods by incorporating the generalized volume scattering model (GVSM or simplified adaptive volume scattering model, (SAVSM proposed by Antropov et al. and Huang et al., respectively, into the general decomposition framework proposed by Chen et al. By doing so, the final volume coherency matrix structure is selected from a wide range of volume scattering models within a continuous interval according to the data itself without adding unknowns. Moreover, the new approaches rely on one nonlinear optimization stage instead of four as in the previous method proposed by Chen et al. In addition, the parameter inversion procedure adopts the modified algorithm proposed by Xie et al. which leads to higher accuracy and more physically reliable output parameters. A number of Monte Carlo simulations of polarimetric synthetic aperture radar (PolSAR data are carried out and show that the proposed method with GVSM yields an overall improvement in the final accuracy of estimated parameters and outperforms both the version using SAVSM and the original approach. In addition, C-band Radarsat-2 and L-band AIRSAR fully polarimetric images over the San Francisco region are also used for testing purposes. A detailed comparison and analysis of decomposition results over different land-cover types are conducted. According to this study, the use of general decomposition models leads to a more accurate quantitative retrieval of target parameters. However, there

  16. Solar concentrator technology development for space based applications, volume 1

    Science.gov (United States)

    Pintz, A.; Castle, C. H.; Reimer, R. R.

    1992-01-01

    Thermoelectric conversion using a radio-isotope heat source has been used where outer planetary space craft are too far away for absorbing significant solar energy. Solar dynamic power (SDP) conversion is one technology that offers advantages for applications within the inner planet region. Since SDP conversion efficiency can be 2 to 3 times higher than photovoltaic, the collecting surfaces are much reduced in area and therefore lighter. This becomes an advantage in allocating more weight to launched payloads. A second advantage results for low earth orbit applications. The reduced area results in lower drag forces on the spacecraft and requires less reboost propellant to maintain orbit. A third advantage occurs because of the sun-to-shade cycling while in earth orbit. Photovoltaic systems require batteries to store energy for use when in the shade, and battery life for periods of 10 to 15 years is not presently achievable. For these reasons the Solar Dynamics and Thermal Systems Branch at NASA LeRC has funded work in developing SDP systems. The generic SDP system uses a large parabolic solar concentrator to focus solar energy onto a power conversion device. The concentrators are large areas and must therefore be efficient and have low specific weights. Yet these surfaces must be precise and capable of being stowed in a launch vehicle and then deployed and sometimes unfurled in space. There are significant technical challenges in engineering such structures, and considerable investigation has been made to date. This is the first of two volumes reporting on the research done by the Advanced Manufacturing Center at Cleveland State University to assist NASA LeRC in evaluating this technology. The objective of the grant was to restore the solar concentrator development technology of the 1960s while improving it with advances that have occurred since then. This report summarizes the work done from January 1989 through December 1991.

  17. Structure-based design in the GPCR target space.

    Science.gov (United States)

    Kontoyianni, M; Liu, Z

    2012-01-01

    The G protein-coupled receptors (GPCRs) are membrane proteins that transmit signals via G-protein coupling. They have long been the target of small molecule therapeutics accounting for 30% of the launched drug targets. They are subdivided into several classes, with rhodopsins corresponding to the largest class. Furthermore, a high number of new rhodopsin-like GPCR proteins are included in the druggable genome, thus they are projected to continue being of value to the pharmaceutical and biotechnology sectors. We present a comprehensive review of the structural information pertaining to GPCRs, in light of the most recently deposited crystal structures, along with comparisons of the available to-date structures at different activation states. Finally, computational approaches to GPCR modeling are discussed in conjunction with critical perspectives regarding feasibility and limitations.

  18. Sonar target localization based on spike coded spectrograms

    Directory of Open Access Journals (Sweden)

    Bertrand FONTAINE

    2006-12-01

    Full Text Available Target location is coded into the pattern of spikes that run up the auditory nerve to the bat's brain. Realistic scenes containing multiple, closely spaced, reflectors give rise to complex echo signals consisting of multiple filtered copies of the bat's own vocalisation. Some of this filtering is due to the directivity of the bat’s reception system i.e., the outer ears, and some of it is due to sound absorption and the reflection process. The analysis below concentrates on the conspicuous ridges (notches these filter operations give rise to in the time-frequency representation of the echo as produced by the bat's inner ear. Assuming multiple threshold detecting neurons for each frequency channel it is shown how the distribution of spike times within the generated spike bursts is linked to the presence and characteristics of these notches. A neural network decoding the spike bursts in terms of target location is described.

  19. Electron scattering based on a novel internal target technique: SCRIT

    Energy Technology Data Exchange (ETDEWEB)

    Wakasugi, M.; Emoto, T.; Ito, S.; Wang, S.; Suda, T.; Yano, Y. [RIKEN Nishina Center, Saitama (Japan); Kurita, K.; Ishii, K. [Rikkyo University, Rikkyo (Japan); Tamae, T.; Kuwajima, A. [Tohoku University, Tohoku (Japan); Noda, A.; Shiari, T.; Tongu, H. [Kyoto University, Kyoto (Japan)

    2009-12-15

    A novel technique for forming internal targets, named SCRIT (Self-Confining RI Ion Target), has been developed, which can make electron scattering off short-lived radioactive nuclei possible in an electron storage ring. SCRIT confines the ions of interest by utilizing the ''ion trapping'' phenomenon in the electron storage ring. Approximately 10{sup 7} stable {sup 133}Cs ions were trapped in a three-dimensional configuration along the electron beam axis at an electron beam current of 75 mA. The angular distribution of the electrons scattered from the trapped {sup 133}Cs ions was successfully measured, and a collision luminosity of 10{sup 26}/(cm{sup 2} s) was achieved. (orig.)

  20. Web-based tailored lifestyle programs: exploration of the target group's interests and implications for practice.

    NARCIS (Netherlands)

    Verheijden, M.W.; Jans, M.P.; Hildebrandt, V.H.

    2008-01-01

    An important challenge in Web-based health promotion is to increase the reach of the target audience by taking the target groups' desires into consideration. Data from 505 members of a Dutch Internet panel (representative for Dutch Internet users) were used to asses the target group's interests and

  1. Targeting Customers for Demand Response Based on Big Data

    OpenAIRE

    Kwac, Jungsuk; Rajagopal, Ram

    2014-01-01

    Selecting customers for demand response programs is challenging and existing methodologies are hard to scale and poor in performance. The existing methods were limited by lack of temporal consumption information at the individual customer level. We propose a scalable methodology for demand response targeting utilizing novel data available from smart meters. The approach relies on formulating the problem as a stochastic integer program involving predicted customer responses. A novel approximat...

  2. Exploring Polypharmacology Using a ROCS-Based Target Fishing Approach

    Science.gov (United States)

    2012-01-01

    will interact with the target. Abbreviations: DB number, Drug Bank number; ATC, anatomical therapeutic chemical classification; AMPC, AmpC β- lactamase ...receptor 2; ALR2, aldose reductase 2; AmpC, AmpC β- lactamase ; AUC, area under the curve. Journal of Chemical Information and Modeling Article dx.doi.org...Fluanisone, and (C) Fluoxetine. Abbreviations: ALPHA, α adrenergic receptor; D, dopamine receptor; BETA , β adrenergic receptor; H1, histamine H1 receptor

  3. Effect of hospital volume on processes of breast cancer care: A National Cancer Data Base study.

    Science.gov (United States)

    Yen, Tina W F; Pezzin, Liliana E; Li, Jianing; Sparapani, Rodney; Laud, Purushuttom W; Nattinger, Ann B

    2017-05-15

    The purpose of this study was to examine variations in delivery of several breast cancer processes of care that are correlated with lower mortality and disease recurrence, and to determine the extent to which hospital volume explains this variation. Women who were diagnosed with stage I-III unilateral breast cancer between 2007 and 2011 were identified within the National Cancer Data Base. Multiple logistic regression models were developed to determine whether hospital volume was independently associated with each of 10 individual process of care measures addressing diagnosis and treatment, and 2 composite measures assessing appropriateness of systemic treatment (chemotherapy and hormonal therapy) and locoregional treatment (margin status and radiation therapy). Among 573,571 women treated at 1755 different hospitals, 38%, 51%, and 10% were treated at high-, medium-, and low-volume hospitals, respectively. On multivariate analysis controlling for patient sociodemographic characteristics, treatment year and geographic location, hospital volume was a significant predictor for cancer diagnosis by initial biopsy (medium volume: odds ratio [OR] = 1.15, 95% confidence interval [CI] = 1.05-1.25; high volume: OR = 1.30, 95% CI = 1.14-1.49), negative surgical margins (medium volume: OR = 1.15, 95% CI = 1.06-1.24; high volume: OR = 1.28, 95% CI = 1.13-1.44), and appropriate locoregional treatment (medium volume: OR = 1.12, 95% CI = 1.07-1.17; high volume: OR = 1.16, 95% CI = 1.09-1.24). Diagnosis of breast cancer before initial surgery, negative surgical margins and appropriate use of radiation therapy may partially explain the volume-survival relationship. Dissemination of these processes of care to a broader group of hospitals could potentially improve the overall quality of care and outcomes of breast cancer survivors. Cancer 2017;123:957-66. © 2016 American Cancer Society. © 2016 American Cancer Society.

  4. Projections for the Production of Bulk Volume Bio-Based Polymers in Europe and Environmental Implications

    NARCIS (Netherlands)

    Patel, M.K.|info:eu-repo/dai/nl/18988097X; Crank, M.

    2007-01-01

    In this paper we provide an overview of the most important emerging groups of bio-based polymers for bulk volume applications and we discuss market projections for these types of bio-based polymers in the EU, thereby distinguishing between three scenarios. Bio-based polymers are projected to reach a

  5. Host target-based approaches against arboviral diseases.

    Science.gov (United States)

    Rocha, Rebeca Froes; Del Sarto, Juliana Lemos; Marques, Rafael Elias; Costa, Vivian Vasconcelos; Teixeira, Mauro Martins

    2018-02-23

    In the 20th century, socioeconomic and environmental changes facilitated the reintroduction of mosquitoes in developing cities, resulting in the reinsertion of mosquito-borne viral diseases and the dispersal of their causative agents on a worldwide scale. Recurrent outbreaks of arboviral diseases are being reported, even in regions without a previous history of arboviral disease transmission. Of note, arboviral infections represented approximately 30% of all emerging vector-borne diseases in the last decade. Therapeutic strategies against infectious viral diseases include the use of different classes of molecules that act directly on the pathogen and/or act by optimizing the host immune response. Drugs targeting the virus usually provide amelioration of symptoms by suppressing and controlling the infection. However, it is limited by the short-window of effectiveness, ineffectiveness against latent viruses, development of drug-resistant mutants and toxic side effects. Disease may also be a consequence of an excessive, uncontrolled or misplaced inflammatory response, treatments that interfere in host immune response are interesting options and can be used isolated or in combination with virus-targeted therapies. The use of host-targeted therapies requires specific knowledge regarding host immune patterns that may trigger dengue virus (DENV), chikungunya virus (CHIKV) or Zika virus (ZIKV) disease.

  6. Polymer-Based Novel Lung Targeted Delivery Systems.

    Science.gov (United States)

    Elmowafy, Enas; Osman, Rihab; Ishak, Rania A H

    2017-01-01

    Due to its unique features, the respiratory tract had received great attention as a promising non-invasive route for drug administration to achieve both local and systemic effects. Efforts spent to tailor systems able to overcome the lung defence mechanisms and biological barriers are followed in this review. Aerodynamic diameter, morphology, lung deposition and drug release profiles are the main criteria describing the selected new smart lung targeted delivery systems. Novel systems such as nanoparticles, nano-embedded-in microparticles (NEM), small microparticles (MP), large porous particles (LPP), PulmospheresTM and polymeric micelles are used to passively target different areas in the respiratory tract. The most common preparation methods are outlined in the article. Special emphasis was given to the characteristics of the polymers used to fabricate the developed systems. Efforts made to prepare systems using chitosan (CS), alginate (alg), hyaluronic acid (HA), gelatin and albumin as examples of natural polymers and poly lactic-co-glycolic acid (PLGA) and poly(Ɛ-caprolactone) (PCL) as synthetic polymers were compiled. The continuous development and work in the area of lung targeting resulted in the development of engineered smart platforms with the capability to carry small drug molecules, proteins and genes to treat a variety of local and systemic diseases. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. High-Frequency Jet Ventilation for Complete Target Immobilization and Reduction of Planning Target Volume in Stereotactic High Single-Dose Irradiation of Stage I Non-Small Cell Lung Cancer and Lung Metastases

    International Nuclear Information System (INIS)

    Fritz, Peter; Kraus, Hans-Joerg; Muehlnickel, Werner; Sassmann, Volker; Hering, Werner; Strauch, Konstantin

    2010-01-01

    Purpose: To demonstrate the feasibility of complete target immobilization by means of high-frequency jet ventilation (HFJV); and to show that the saving of planning target volume (PTV) on the stereotactic body radiation therapy (SBRT) under HFJV, compared with SBRT with respiratory motion, can be predicted with reliable accuracy by computed tomography (CT) scans at peak inspiration phase. Methods and Materials: A comparison regarding different methods for defining the PTV was carried out in 22 patients with tumors that clearly moved with respiration. A movement span of the gross tumor volume (GTV) was defined by fusing respiration-correlated CT scans. The PTV enclosed the GTV positions with a safety margin throughout the breathing cycle. To create a PTV from CT scans acquired under HFJV, the same margins were drawn around the immobilized target. In addition, peak inspiration phase CT images (PIP-CTs) were used to approximate a target immobilized by HFJV. Results: The resulting HFJV-PTVs were between 11.6% and 45.4% smaller than the baseline values calculated as respiration-correlated CT-PTVs (median volume reduction, 25.4%). Tentative planning by means of PIP-CT PTVs predicted that in 19 of 22 patients, use of HFJV would lead to a reduction in volume of ≥20%. Using this threshold yielded a positive predictive value of 0.89, as well as a sensitivity of 0.94 and a specificity of 0.5. Conclusions: In all patients, SBRT under HFJV provided a reliable immobilization of the GTVs and achieved a reduction in PTVs, regardless of patient compliance. Tentative planning facilitated the selection of patients who could better undergo radiation in respiratory standstill, both with greater accuracy and lung protection.

  8. Infrared small target detection based on local intensity and gradient properties

    Science.gov (United States)

    Zhang, Hong; Zhang, Lei; Yuan, Ding; Chen, Hao

    2018-03-01

    Infrared small target detection is a challenging task for computer vision due to the factors such as scale variations of the targets and strong clutters. Inspired by the Gaussian-like shape of the small target, we characterize two local properties of the small target from the perspective of intensity and gradient to address this problem. The two properties are that the intensity value of the target pixels is greater than the value of its locally neighboring pixels, and the gradients towards the target center often distribute regularly around the target. First, based on the two properties, the local intensity and gradient (LIG) map is calculated from the original infrared image in order to enhance the targets and suppress clutters. Next, we can obtain the targets conveniently via segmentation from the LIG map. Extensive evaluations on real data demonstrate that the proposed algorithm has satisfactory results in terms of clutter suppression and robustness.

  9. ACCURATUM: improved calcium volume scoring using a mesh-based algorithm - a phantom study

    International Nuclear Information System (INIS)

    Saur, Stefan C.; Szekely, Gabor; Alkadhi, Hatem; Desbiolles, Lotus; Cattin, Philippe C.

    2009-01-01

    To overcome the limitations of the classical volume scoring method for quantifying coronary calcifications, including accuracy, variability between examinations, and dependency on plaque density and acquisition parameters, a mesh-based volume measurement method has been developed. It was evaluated and compared with the classical volume scoring method for accuracy, i.e., the normalized volume (measured volume/ground-truthed volume), and for variability between examinations (standard deviation of accuracy). A cardiac computed-tomography (CT) phantom containing various cylindrical calcifications was scanned using different tube voltages and reconstruction kernels, at various positions and orientations on the CT table and using different slice thicknesses. Mean accuracy for all plaques was significantly higher (p<0.0001) for the proposed method (1.220±0.507) than for the classical volume score (1.896±1.095). In contrast to the classical volume score, plaque density (p=0.84), reconstruction kernel (p=0.19), and tube voltage (p=0.27) had no impact on the accuracy of the developed method. In conclusion, the method presented herein is more accurate than classical calcium scoring and is less dependent on tube voltage, reconstruction kernel, and plaque density. (orig.)

  10. Research on Warehouse Target Localization and Tracking Based on KF and WSN

    Directory of Open Access Journals (Sweden)

    Guang-Rong BIAN

    2014-01-01

    Full Text Available This paper firstly established the model of warehouse targeting and tracking system based on Wireless Sensor Networks (WSN. The principle of Location and tracking is based on the maximum likelihood estimation method of multilateral measurement. According to monitoring motion trajectory of the same unknown target node within a continuous period of time, the motion equation can be established. It can achieve the effective tracking of warehouse target that KF algorithm is applied to carrying out the state estimation of warehouse target motion equation. Simulation results show that, while the warehouse target tracking system state equations are linear, using KF algorithm can obtain satisfactory tracking accuracy.

  11. Gamut Volume Index: a color preference metric based on meta-analysis and optimized colour samples.

    Science.gov (United States)

    Liu, Qiang; Huang, Zheng; Xiao, Kaida; Pointer, Michael R; Westland, Stephen; Luo, M Ronnier

    2017-07-10

    A novel metric named Gamut Volume Index (GVI) is proposed for evaluating the colour preference of lighting. This metric is based on the absolute gamut volume of optimized colour samples. The optimal colour set of the proposed metric was obtained by optimizing the weighted average correlation between the metric predictions and the subjective ratings for 8 psychophysical studies. The performance of 20 typical colour metrics was also investigated, which included colour difference based metrics, gamut based metrics, memory based metrics as well as combined metrics. It was found that the proposed GVI outperformed the existing counterparts, especially for the conditions where correlated colour temperatures differed.

  12. Methodological approaches to planar and volumetric scintigraphic imaging of small volume targets with high spatial resolution and sensitivity

    Directory of Open Access Journals (Sweden)

    J. Mejia

    2009-08-01

    Full Text Available Single-photon emission computed tomography (SPECT is a non-invasive imaging technique, which provides information reporting the functional states of tissues. SPECT imaging has been used as a diagnostic tool in several human disorders and can be used in animal models of diseases for physiopathological, genomic and drug discovery studies. However, most of the experimental models used in research involve rodents, which are at least one order of magnitude smaller in linear dimensions than man. Consequently, images of targets obtained with conventional gamma-cameras and collimators have poor spatial resolution and statistical quality. We review the methodological approaches developed in recent years in order to obtain images of small targets with good spatial resolution and sensitivity. Multipinhole, coded mask- and slit-based collimators are presented as alternative approaches to improve image quality. In combination with appropriate decoding algorithms, these collimators permit a significant reduction of the time needed to register the projections used to make 3-D representations of the volumetric distribution of target’s radiotracers. Simultaneously, they can be used to minimize artifacts and blurring arising when single pinhole collimators are used. Representation images are presented, which illustrate the use of these collimators. We also comment on the use of coded masks to attain tomographic resolution with a single projection, as discussed by some investigators since their introduction to obtain near-field images. We conclude this review by showing that the use of appropriate hardware and software tools adapted to conventional gamma-cameras can be of great help in obtaining relevant functional information in experiments using small animals.

  13. Research on autonomous identification of airport targets based on Gabor filtering and Radon transform

    Science.gov (United States)

    Yi, Juan; Du, Qingyu; Zhang, Hong jiang; Zhang, Yao lei

    2017-11-01

    Target recognition is a leading key technology in intelligent image processing and application development at present, with the enhancement of computer processing ability, autonomous target recognition algorithm, gradually improve intelligence, and showed good adaptability. Taking the airport target as the research object, analysis the airport layout characteristics, construction of knowledge model, Gabor filter and Radon transform based on the target recognition algorithm of independent design, image processing and feature extraction of the airport, the algorithm was verified, and achieved better recognition results.

  14. WaVPeak: Picking NMR peaks through wavelet-based smoothing and volume-based filtering

    KAUST Repository

    Liu, Zhi

    2012-02-10

    Motivation: Nuclear magnetic resonance (NMR) has been widely used as a powerful tool to determine the 3D structures of proteins in vivo. However, the post-spectra processing stage of NMR structure determination usually involves a tremendous amount of time and expert knowledge, which includes peak picking, chemical shift assignment and structure calculation steps. Detecting accurate peaks from the NMR spectra is a prerequisite for all following steps, and thus remains a key problem in automatic NMR structure determination. Results: We introduce WaVPeak, a fully automatic peak detection method. WaVPeak first smoothes the given NMR spectrum by wavelets. The peaks are then identified as the local maxima. The false positive peaks are filtered out efficiently by considering the volume of the peaks. WaVPeak has two major advantages over the state-of-the-art peak-picking methods. First, through wavelet-based smoothing, WaVPeak does not eliminate any data point in the spectra. Therefore, WaVPeak is able to detect weak peaks that are embedded in the noise level. NMR spectroscopists need the most help isolating these weak peaks. Second, WaVPeak estimates the volume of the peaks to filter the false positives. This is more reliable than intensity-based filters that are widely used in existing methods. We evaluate the performance of WaVPeak on the benchmark set proposed by PICKY (Alipanahi et al., 2009), one of the most accurate methods in the literature. The dataset comprises 32 2D and 3D spectra from eight different proteins. Experimental results demonstrate that WaVPeak achieves an average of 96%, 91%, 88%, 76% and 85% recall on 15N-HSQC, HNCO, HNCA, HNCACB and CBCA(CO)NH, respectively. When the same number of peaks are considered, WaVPeak significantly outperforms PICKY. The Author(s) 2012. Published by Oxford University Press.

  15. High-resolution x-ray imaging of Kα volume radiation induced by high-intensity laser pulse interaction with a copper target

    Czech Academy of Sciences Publication Activity Database

    Galtier, E.; Moinard, A.; Khattak, F.Y.; Renner, Oldřich; Robert, T.; Santos, J.J.; Beaucourt, C.; Angelo, P.; Tikhonchuk, V.; Rosmej, F.B.

    2012-01-01

    Roč. 45, č. 20 (2012), s. 1-6 ISSN 0953-4075 R&D Projects: GA ČR GAP205/10/0814 Institutional research plan: CEZ:AV0Z10100523 Keywords : laser-matter interaction * x-ray spectroscopy * particle generation * x-ray imaging * Kα volume radiation * Cu targets Subject RIV: BH - Optics, Masers, Lasers Impact factor: 2.031, year: 2012

  16. Evaluation of variability in target volume delineation for newly diagnosed glioblastoma: a multi-institutional study from the Korean Radiation Oncology Group.

    Science.gov (United States)

    Wee, Chan Woo; Sung, Wonmo; Kang, Hyun-Cheol; Cho, Kwan Ho; Han, Tae Jin; Jeong, Bae-Kwon; Jeong, Jae-Uk; Kim, Haeyoung; Kim, In Ah; Kim, Jin Hee; Kim, Sung Hwan; Kim, Suzy; Lee, Dong Soo; Lee, Me Yeon; Lim, Do Hoon; Park, Hye Li; Suh, Chang-Ok; Yoon, Sang Min; Kim, Il Han

    2015-07-02

    This study aimed for a collaborative evaluation of variability in the target volumes for glioblastoma, determined and contoured by different radiotherapy (RT) facilities in Korea. Fifteen panels of radiation oncologists from independent institutions contoured the gross target volumes (GTVs) and clinical target volumes (CTVs) for 3-dimensional conformal RT or intensity-modulated RT on each simulation CT images, after scrutinizing the enhanced T1-weighted and T2-weighted-fluid-attenuated inversion recovery MR images of 9 different cases of glioblastoma. Degrees of contouring agreement were analyzed by the kappa statistics. Using the algorithm of simultaneous truth and performance level estimation (STAPLE), GTVSTAPLE and CTVSTAPLE contours were derived. Contour agreement was moderate (mean kappa 0.58) among the GTVs and was substantial (mean kappa 0.65) among the CTVs. However, each panels' GTVs and modification of CTVs regarding anatomical structures varied. Three-fourth of contoured panels' CTVs encompassed the peritumoral areas of T2-high signal intensity (T2-HSI). Nine of nine GTVSTAPLE encompased the surgical cavity and the T1-enhanced lesions. Eight of nine CTVSTAPLE encompassed the peritumoral T2-HSI area. The median MARGIN90 and the median MARGIN95 were 1.4 cm and 1.5 cm, respectively. Moderate to substantial agreement existed in target volumes for 3-dimensional or intensity-modulated RT determined by radiation oncologists in Korea. According to the estimated consensus contours, the initial CTV encompassed the GTV with margin less than 2.0 cm and the whole peritumoral areas of T2-HSI. The findings of our study propose the need for further studies and modified guidelines.

  17. Guidelines for target volume definition in post-operative radiotherapy for prostate cancer, on behalf of the EORTC Radiation Oncology Group

    International Nuclear Information System (INIS)

    Poortmans, Philip; Bossi, Alberto; Vandeputte, Katia; Bosset, Mathieu; Miralbell, Raymond; Maingon, Philippe; Boehmer, Dirk; Budiharto, Tom; Symon, Zvi; Bergh, Alfons C.M. van den; Scrase, Christopher; Poppel, Hendrik van; Bolla, Michel

    2007-01-01

    The appropriate application of 3-D conformal radiotherapy, intensity modulated radiotherapy or image guided radiotherapy for patients undergoing post-operative radiotherapy for prostate cancer requires a standardisation of the target volume definition and delineation as well as standardisation of the clinical quality assurance procedures. Recommendations for this are presented on behalf of the European Organisation for Research and Treatment of Cancer (EORTC) Radiation Oncology Group and in addition to the already published guidelines for radiotherapy as the primary treatment

  18. Potential dosimetric benefits of adaptive tumor tracking over the internal target volume concept for stereotactic body radiation therapy of pancreatic cancer.

    Science.gov (United States)

    Karava, Konstantina; Ehrbar, Stefanie; Riesterer, Oliver; Roesch, Johannes; Glatz, Stefan; Klöck, Stephan; Guckenberger, Matthias; Tanadini-Lang, Stephanie

    2017-11-09

    Radiotherapy for pancreatic cancer has two major challenges: (I) the tumor is adjacent to several critical organs and, (II) the mobility of both, the tumor and its surrounding organs at risk (OARs). A treatment planning study simulating stereotactic body radiation therapy (SBRT) for pancreatic tumors with both the internal target volume (ITV) concept and the tumor tracking approach was performed. The two respiratory motion-management techniques were compared in terms of doses to the target volume and organs at risk. Two volumetric-modulated arc therapy (VMAT) treatment plans (5 × 5 Gy) were created for each of the 12 previously treated pancreatic cancer patients, one using the ITV concept and one the tumor tracking approach. To better evaluate the overall dose delivered to the moving tumor volume, 4D dose calculations were performed on four-dimensional computed tomography (4DCT) scans. The resulting planning target volume (PTV) size for each technique was analyzed. Target and OAR dose parameters were reported and analyzed for both 3D and 4D dose calculation. Tumor motion ranged from 1.3 to 11.2 mm. Tracking led to a reduction of PTV size (max. 39.2%) accompanied with significant better tumor coverage (p<0.05, paired Wilcoxon signed rank test) both in 3D and 4D dose calculations and improved organ at risk sparing. Especially for duodenum, stomach and liver, the mean dose was significantly reduced (p<0.05) with tracking for 3D and 4D dose calculations. By using an adaptive tumor tracking approach for respiratory-induced pancreatic motion management, a significant reduction in PTV size can be achieved, which subsequently facilitates treatment planning, and improves organ dose sparing. The dosimetric benefit of tumor tracking is organ and patient-specific.

  19. Daily Isocenter Correction With Electromagnetic-Based Localization Improves Target Coverage and Rectal Sparing During Prostate Radiotherapy

    International Nuclear Information System (INIS)

    Rajendran, Ramji Ramaswamy; Plastaras, John P.; Mick, Rosemarie; McMichael Kohler, Diane; Kassaee, Alireza; Vapiwala, Neha

    2010-01-01

    Purpose: To evaluate dosimetric consequences of daily isocenter correction during prostate cancer radiation therapy using the Calypso 4D localization system. Methods and Materials: Data were analyzed from 28 patients with electromagnetic transponders implanted in their prostates for daily target localization and tracking. Treatment planning isocenters were recorded based on the values of the vertical, longitudinal, and lateral axes. Isocenter location obtained via alignment with skin tattoos was compared with that obtained via the electromagnetic localization system. Daily isocenter shifts, based on the isocenter location differences between the two alignment methods in each spatial axis, were calculated for each patient over their entire course. The mean isocenter shifts were used to determine dosimetric consequences of treatment based on skin tattoo alignments alone. Results: The mean += SD of the percentages of treatment days with shifts beyond += 0.5 cm for vertical, longitudinal and lateral shifts were 62% += 28%, 35% += 26%, and 38% +=21%, respectively. If daily electromagnetic localization was not used, the excess in prescribed dose delivered to 70% of the rectum was 10 Gy and the deficit in prescribed dose delivered to 95% of the planning target volume was 10 Gy. The mean isocenter shift was not associated with the volumes of the prostate, rectum, or bladder, or with patient body mass index. Conclusions: Daily isocenter localization can reduce the treatment dose to the rectum. Correcting for this variability could lead to improved dose delivery, reduced side effects, and potentially improved treatment outcomes.

  20. An ancient relation between units of length and volume based on a sphere.

    Directory of Open Access Journals (Sweden)

    Elena Zapassky

    Full Text Available The modern metric system defines units of volume based on the cube. We propose that the ancient Egyptian system of measuring capacity employed a similar concept, but used the sphere instead. When considered in ancient Egyptian units, the volume of a sphere, whose circumference is one royal cubit, equals half a hekat. Using the measurements of large sets of ancient containers as a database, the article demonstrates that this formula was characteristic of Egyptian and Egyptian-related pottery vessels but not of the ceramics of Mesopotamia, which had a different system of measuring length and volume units.

  1. A method of measuring stacked objects volume based on laser sensing

    Science.gov (United States)

    Zhao, Qijie; Wu, Yijing; Li, Xianfa; Xu, Jiao; Meng, Qingxu

    2017-10-01

    Stacked objects volume measurement is now widely used in the fields of enterprise material management. It is significant to improve the efficiency of enterprise management and to reduce the cost of management and operation. The method based on laser sensing is one of the key methods to measure the stacked objects volume. This paper presents a laser sensing measurement method of stacked objects based on bottom plane extraction and real-time calibration. A calibration method for a laser scanning sensor and inertial measurement sensor is proposed. Three-dimensional reconstructions of stacked objects and volume calculations are carried out after acquisition and processing of point clouds. Volume measurement experiments of the single box and stacked boxes have been conducted respectively. Experimental results show that the measurement method is feasible and valid with good accuracy.

  2. What's new in target volume definition for radiologists in ICRU Report 71? How can the ICRU volume definitions be integrated in clinical practice?

    DEFF Research Database (Denmark)

    Berthelsen, Anne Kiil; Dobbs, Jane; Kjellén, Elisabeth

    2007-01-01

    The optimal definition of the size, shape and location of gross tumour volume is one of the most important steps in the planning of radiation therapy, and necessitates a proper understanding of the procedure from both the oncologic radiologist and the radiation oncologist. This overview reports...... on the different terms and concepts that have been recommended in the ICRU Reports for this purpose; the latest Report 71 focuses on both previously given recommendations, and especially on electron beam therapy. This paper also highlights some of the problems that are encountered in the use of the International...

  3. Kernel method for clustering based on optimal target vector

    International Nuclear Information System (INIS)

    Angelini, Leonardo; Marinazzo, Daniele; Pellicoro, Mario; Stramaglia, Sebastiano

    2006-01-01

    We introduce Ising models, suitable for dichotomic clustering, with couplings that are (i) both ferro- and anti-ferromagnetic (ii) depending on the whole data-set and not only on pairs of samples. Couplings are determined exploiting the notion of optimal target vector, here introduced, a link between kernel supervised and unsupervised learning. The effectiveness of the method is shown in the case of the well-known iris data-set and in benchmarks of gene expression levels, where it works better than existing methods for dichotomic clustering

  4. Information base for waste repository design. Volume 5. Decommissioning of underground facilities. Technical report

    International Nuclear Information System (INIS)

    Giuffre, M.S.; Plum, R.L.; Koplik, C.M.; Talbot, R.

    1979-03-01

    This report is Volume 5 of a seven volume document on nuclear waste repository design issues. This report discusses the requirements for decommissioning a deep underground facility for the disposal of radioactive waste. The techniques for sealing the mined excavations are presented and an information base on potential backfill materials is provided. Possible requirements for monitoring the site are discussed. The performance requirements for backfill materials are outlined. The advantages and disadvantages of each sealing method are stated

  5. The Microgravity Research Experiments (MICREX) Data Base. Volume 1

    Science.gov (United States)

    Winter, C. A.; Jones, J.C.

    1996-01-01

    An electronic data base identifying over 800 fluids and materials processing experiments performed in a low-gravity environment has been created at NASA Marshall Space Flight Center. The compilation, called MICREX (MICrogravity Research Experiments), was designed to document all such experimental efforts performed (1) on U.S. manned space vehicles, (2) on payloads deployed from U.S. manned space vehicles, and (3) on all domestic and international sounding rockets (excluding those of China and the former U.S.S.R.). Data available on most experiments include (1) principal and co-investigators, (2) low-gravity mission, (3) processing facility, (4) experimental objectives and results, (5) identifying key words, (6) sample materials, (7) applications of the processed materials/research area, (8) experiment descriptive publications, and (9) contacts for more information concerning the experiment. This technical memorandum (1) summarizes the historical interest in reduced-gravity fluid dynamics, (2) describes the experimental facilities employed to examine reduced gravity fluid flow, (3) discusses the importance of a low-gravity fluids and materials processing data base, (4) describes the MICREX data base format and computational World Wide Web access procedures, and (5) documents (in hard-copy form) the descriptions of the first 600 fluids and materials processing experiments entered into MICREX.

  6. Automated Navigation System based on Weapon-Target Assignment

    Directory of Open Access Journals (Sweden)

    Mohammad Khairudin

    2011-12-01

    Full Text Available Operating of weapon on the tank is mostly by manually. It is not desired performance for a critical operation. An automatic control system is required to operate the weapon with the target while maintaining the accuracy. In this paper has designed an automatic weapon control system using object image proccessing. Various an image processing methods used to improve the weapon accuracy to obtain the intended target. The method used in digital image processing is the Camshift motion tracking method. This method is compared with the Lucas Canade motion tracking method. This comparison is conducted to found more precise results between the two methods. Results of object image processing are used to control the direction of the weapon that towards the desired goal. The results show that the implementation of the Lucas Canade motion tracking method using fire simulation tools have been successful. The performance of the Lucas Canade motion tracking methods is better than the CamShift method. Using Lucas Canade method for weapon controller is accordance with the purposes.

  7. [Research on living tree volume forecast based on PSO embedding SVM].

    Science.gov (United States)

    Jiao, You-Quan; Feng, Zhong-Ke; Zhao, Li-Xi; Xu, Wei-Heng; Cao, Zhong

    2014-01-01

    In order to establish volume model,living trees have to be fallen and be divided into many sections, which is a kind of destructive experiment. So hundreds of thousands of trees have been fallen down each year in China. To solve this problem, a new method called living tree volume accurate measurement without falling tree was proposed in the present paper. In the method, new measuring methods and calculation ways are used by using photoelectric theodolite and auxiliary artificial measurement. The diameter at breast height and diameter at ground was measured manually, and diameters at other heights were obtained by photoelectric theodolite. Tree volume and height of each tree was calculated by a special software that was programmed by the authors. Zhonglin aspens No. 107 were selected as experiment object, and 400 data records were obtained. Based on these data, a nonlinear intelligent living tree volume prediction model with Particle Swarm Optimization algorithm based on support vector machines (PSO-SVM) was established. Three hundred data records including tree height and diameter at breast height were randomly selected form a total of 400 data records as input data, tree volume as output data, using PSO-SVM tool box of Matlab7.11, thus a tree volume model was obtained. One hundred data records were used to test the volume model. The results show that the complex correlation coefficient (R2) between predicted and measured values is 0. 91, which is 2% higher than the value calculated by classic Spurr binary volume model, and the mean absolute error rates were reduced by 0.44%. Compared with Spurr binary volume model, PSO-SVM model has self-learning and self-adaption ability,moreover, with the characteristics of high prediction accuracy, fast learning speed,and a small sample size requirement, PSO-SVM model with well prospect is worth popularization and application.

  8. Pathology-based validation of FDG PET segmentation tools for volume assessment of lymph node metastases from head and neck cancer

    Energy Technology Data Exchange (ETDEWEB)

    Schinagl, Dominic A.X. [Radboud University Nijmegen Medical Centre, Department of Radiation Oncology, Nijmegen (Netherlands); Radboud University Nijmegen Medical Centre, Department of Radiation Oncology (874), P.O. Box 9101, Nijmegen (Netherlands); Span, Paul N.; Kaanders, Johannes H.A.M. [Radboud University Nijmegen Medical Centre, Department of Radiation Oncology, Nijmegen (Netherlands); Hoogen, Frank J.A. van den [Radboud University Nijmegen Medical Centre, Department of Otorhinolaryngology, Head and Neck Surgery, Nijmegen (Netherlands); Merkx, Matthias A.W. [Radboud University Nijmegen Medical Centre, Department of Oral and Maxillofacial Surgery, Nijmegen (Netherlands); Slootweg, Piet J. [Radboud University Nijmegen Medical Centre, Department of Pathology, Nijmegen (Netherlands); Oyen, Wim J.G. [Radboud University Nijmegen Medical Centre, Department of Nuclear Medicine, Nijmegen (Netherlands)

    2013-12-15

    FDG PET is increasingly incorporated into radiation treatment planning of head and neck cancer. However, there are only limited data on the accuracy of radiotherapy target volume delineation by FDG PET. The purpose of this study was to validate FDG PET segmentation tools for volume assessment of lymph node metastases from head and neck cancer against the pathological method as the standard. Twelve patients with head and neck cancer and 28 metastatic lymph nodes eligible for therapeutic neck dissection underwent preoperative FDG PET/CT. The metastatic lymph nodes were delineated on CT (Node{sub CT}) and ten PET segmentation tools were used to assess FDG PET-based nodal volumes: interpreting FDG PET visually (PET{sub VIS}), applying an isocontour at a standardized uptake value (SUV) of 2.5 (PET{sub SUV}), two segmentation tools with a fixed threshold of 40 % and 50 %, and two adaptive threshold based methods. The latter four tools were applied with the primary tumour as reference and also with the lymph node itself as reference. Nodal volumes were compared with the true volume as determined by pathological examination. Both Node{sub CT} and PET{sub VIS} showed good correlations with the pathological volume. PET segmentation tools using the metastatic node as reference all performed well but not better than PET{sub VIS}. The tools using the primary tumour as reference correlated poorly with pathology. PET{sub SUV} was unsatisfactory in 35 % of the patients due to merging of the contours of adjacent nodes. FDG PET accurately estimates metastatic lymph node volume, but beyond the detection of lymph node metastases (staging), it has no added value over CT alone for the delineation of routine radiotherapy target volumes. If FDG PET is used in radiotherapy planning, treatment adaptation or response assessment, we recommend an automated segmentation method for purposes of reproducibility and interinstitutional comparison. (orig.)

  9. Consensus Guidelines for Delineation of Clinical Target Volume for Intensity-Modulated Pelvic Radiotherapy for the Definitive Treatment of Cervix Cancer

    International Nuclear Information System (INIS)

    Lim, Karen; Small, William; Portelance, Lorraine; Creutzberg, Carien; Juergenliemk-Schulz, Ina M.; Mundt, Arno; Mell, Loren K.; Mayr, Nina; Viswanathan, Akila; Jhingran, Anuja; Erickson, Beth; De Los Santos, Jennifer; Gaffney, David; Yashar, Catheryn; Beriwal, Sushil; Wolfson, Aaron

    2011-01-01

    Purpose: Accurate target definition is vitally important for definitive treatment of cervix cancer with intensity-modulated radiotherapy (IMRT), yet a definition of clinical target volume (CTV) remains variable within the literature. The aim of this study was to develop a consensus CTV definition in preparation for a Phase 2 clinical trial being planned by the Radiation Therapy Oncology Group. Methods and Materials: A guidelines consensus working group meeting was convened in June 2008 for the purposes of developing target definition guidelines for IMRT for the intact cervix. A draft document of recommendations for CTV definition was created and used to aid in contouring a clinical case. The clinical case was then analyzed for consistency and clarity of target delineation using an expectation maximization algorithm for simultaneous truth and performance level estimation (STAPLE), with kappa statistics as a measure of agreement between participants. Results: Nineteen experts in gynecological radiation oncology generated contours on axial magnetic resonance images of the pelvis. Substantial STAPLE agreement sensitivity and specificity values were seen for gross tumor volume (GTV) delineation (0.84 and 0.96, respectively) with a kappa statistic of 0.68 (p < 0.0001). Agreement for delineation of cervix, uterus, vagina, and parametria was moderate. Conclusions: This report provides guidelines for CTV definition in the definitive cervix cancer setting for the purposes of IMRT, building on previously published guidelines for IMRT in the postoperative setting.

  10. Estimation of the mediastinal involvement probability in non-small cell lung cancer: a statistical definition of the clinical target volume for 3-dimensional conformal radiotherapy?

    International Nuclear Information System (INIS)

    Giraud, P.; Dubray, B.; Helfre, S.; Dauphinot, C.; Rosenwald, J.C.; Cosset, J.M.; Rycke, Y. de; Minet, P.; Danhier, S.

    2001-01-01

    Purpose. - Conformal irradiation of non-small cell lung carcinoma (NSCLC) is largely based on a precise definition of the nodal clinical target volume (CTVn). The reduction of the number of nodal stations to be irradiated would render tumor dose escalation more achievable. The aim of this work was to design an mathematical tool based on documented data, that would predict the risk of metastatic involvement for each nodal station. Methods and material. - From the large surgical series published in the literature we looked at the main pre-treatment parameters that modify the risk of nodal invasion. The probability of involvement for the 17 nodal stations described by the American Thoracic Society (ATS) was computed from all these publications and then weighted according to the French epidemiological data. Starting from the primitive location of the tumour as the main characteristic, we built a probabilistic tree for each nodal station representing the risk distribution as a function of each tumor feature. From the statistical point of view, we used the inversion of probability trees method described by Weinstein and Feinberg. Results. -Taking into account all the different parameters of I the pre-treatment staging relative to each level of the ATS map brings up to 20,000 different combinations. The first chosen parameters in the tree were, depending on the tumour location, the histological classification, the metastatic stage, the nodal stage weighted in function of the sensitivity and specificity of the diagnostic examination used (PET scan, CAT scan) and the tumoral stage. A software is proposed to compute a predicted probability of involvement of each nodal station for any given clinical presentation.Conclusion. -To better define the CTVn in NSCLC 3DRT, we propose a software that evaluates the mediastinal nodal involvement risk from easily accessible individual pretreatment parameters. (authors)

  11. Detection algorithm of infrared small target based on improved SUSAN operator

    Science.gov (United States)

    Liu, Xingmiao; Wang, Shicheng; Zhao, Jing

    2010-10-01

    The methods of detecting small moving targets in infrared image sequences that contain moving nuisance objects and background noise is analyzed in this paper. A novel infrared small target detection algorithm based on improved SUSAN operator is put forward. The algorithm selects double templates for the infrared small target detection: one size is greater than the small target point size and another size is equal to the small target point size. First, the algorithm uses the big template to calculate the USAN of each pixel in the image and detect the small target, the edge of the image and isolated noise pixels; Then the algorithm uses the another template to calculate the USAN of pixels detected in the first step and improves the principles of SUSAN algorithm based on the characteristics of the small target so that the algorithm can only detect small targets and don't sensitive to the edge pixels of the image and isolated noise pixels. So the interference of the edge of the image and isolate noise points are removed and the candidate target points can be identified; At last, the target is detected by utilizing the continuity and consistency of target movement. The experimental results indicate that the improved SUSAN detection algorithm can quickly and effectively detect the infrared small targets.

  12. Multiattribute Grey Target Decision Method Based on Soft Set Theory

    Directory of Open Access Journals (Sweden)

    Xia Wang

    2014-01-01

    Full Text Available With respect to the Multiattribute decision-making problems in which the evaluation attribute sets are different and the evaluating values of alternatives are interval grey numbers, a multiattribute grey target decision-making method in which the attribute sets are different was proposed. The concept of grey soft set was defined, and its “AND” operation was assigned by combining the intersection operation of grey number. The expression approach of new grey soft set of attribute sets considering by all decision makers were gained by applying the “AND” operation of grey soft set, and the weights of synthesis attribute were proved. The alternatives were ranked according to the size of distance of bull’s eyes of each alternative under synthetic attribute sets. The green supplier selection was illustrated to demonstrate the effectiveness of proposed model.

  13. 42 CFR 419.30 - Base expenditure target for calendar year 1999.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Base expenditure target for calendar year 1999. 419.30 Section 419.30 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND... Services § 419.30 Base expenditure target for calendar year 1999. (a) CMS estimates the aggregate amount...

  14. A control volume based finite difference method for solving the equilibrium equations in terms of displacements

    DEFF Research Database (Denmark)

    Hattel, Jesper; Hansen, Preben

    1995-01-01

    This paper presents a novel control volume based FD method for solving the equilibrium equations in terms of displacements, i.e. the generalized Navier equations. The method is based on the widely used cv-FDM solution of heat conduction and fluid flow problems involving a staggered grid formulation....... The resulting linear algebraic equations are solved by line-Gauss-Seidel....

  15. Estimation of Reineke and Volume-Based Maximum Size-Density Lines For Shortleaf Pine

    Science.gov (United States)

    Thomas B. Lynch; Robert F. Wittwer; Douglas J. Stevenson

    2004-01-01

    Maximum size-density relationships for Reineke's stand density index as well as for a relationship based on average tree volume were fitted to data from more than a decade of annual remeasurements of plots in unthinned naturally occurring shor tleaf pine in southeaster n Oklahoma. Reineke's stand density index is based on a maximum line of the form log(N) = a...

  16. A Cone Beam CT-Based Study for Clinical Target Definition Using Pelvic Anatomy During Postprostatectomy Radiotherapy

    International Nuclear Information System (INIS)

    Showalter, Timothy N.; Nawaz, A. Omer; Xiao Ying; Galvin, James M.; Valicenti, Richard K.

    2008-01-01

    Purpose: There are no accepted guidelines for target volume definition for online image-guided radiation therapy (IGRT) after radical prostatectomy (RP). This study used cone beam CT (CBCT) imaging to generate information for use in post-RP IGRT. Methods and Materials: The pelvic anatomy of 10 prostate cancer patients undergoing post-RP radiation therapy (RT) to 68.4 Gy was studied using CBCT images obtained immediately before treatment. Contoured bladder and rectal volumes on CBCT images were compared with planning CT (CT ref ) volumes from seminal vesicle stump (SVS) to bladder-urethral junction. This region was chosen to approximate the prostatic fossa (PF) during a course of post-RP RT. Anterior and posterior planning target volume margins were calculated using ICRU report 71 guidelines, accounting for systematic and random error based on bladder and rectal motion, respectively. Results: A total of 176 CBCT study sets obtained 2 to 5 times weekly were analyzed. The rectal and bladder borders were reliably identified in 166 of 176 (94%) of CBCT images. Relative to CT ref , mean posterior bladder wall position was anterior by 0.1 to 1.5 mm, and mean anterior rectum wall position was posterior by 1.6 to 2.7 mm. Calculated anterior margin as derived from bladder motion ranged from 5.9 to 7.1 mm. Calculated posterior margin as derived from rectal motion ranged from 8.6 to 10.2 mm. Conclusions: Normal tissue anatomy was definable by CBCT imaging throughout the course of post-RP RT, and the interfraction anteroposterior motion of the bladder and rectum was studied. This information should be considered in devising post-RP RT techniques using image guidance

  17. Quantitative assessment of inter-clinician variability of target volume delineation for medulloblastoma: quality assurance for the SIOP PNET 4 trial protocol

    International Nuclear Information System (INIS)

    Coles, Charlotte E.; Hoole, Andrew C.F.; Harden, Susan V; Burnet, Neil G.; Twyman, Nicola; Taylor, Roger E.; Kortmann, Rolf D.; Williams, Michael V.

    2003-01-01

    Background and purpose: To assess inter-clinician variability amongst specialist paediatric radiation oncologists in delineating clinical target volumes for treating medulloblastoma as a quality assurance exercise prior to the introduction of the SIOP PNET 4 trial protocol of conformal radiotherapy to the posterior fossa and tumour bed. Patients and methods: Participants from 17 UK centres attended an educational meeting and then completed a clinical planning exercise to outline: (1) the whole posterior fossa and (2) the tumour bed. Quantitative analysis of the volumes, lengths, spatial positioning and axial planes for each individual was carried out and variation between individuals analysed. Results: Outlining of the posterior fossa was reasonably consistent, although most variation was seen in defining the superior border of the tentorium. A major difference was the decision whether or not to include the post-surgical meningocoele in the clinical target volume (CTV). The CTV for the tumour bed was under treated by all participants due to lack of inclusion of pre-operative tumour extent. Conclusions: This exercise demonstrated several ambiguities in the draft protocol and highlighted particular areas of inter-clinician variation. Consequently the protocol was revised and improved to take account of these findings. We recommend that planning exercises, in conjunction with education and training, should be implemented before the start of any new radiotherapy trial. In the future, the use of image transfer will allow prospective peer review of target volumes before treatment commences. These measures are essential to ensure that alterations in clinical practice are achieved in a uniform way

  18. Swarm Robots Search for Multiple Targets Based on an Improved Grouping Strategy.

    Science.gov (United States)

    Tang, Qirong; Ding, Lu; Yu, Fangchao; Zhang, Yuan; Li, Yinghao; Tu, Haibo

    2017-03-14

    Swarm robots search for multiple targets in collaboration in unknown environments has been addressed in this paper. An improved grouping strategy based on constriction factors Particle Swarm Optimization is proposed. Robots are grouped under this strategy after several iterations of stochastic movements, which considers the influence range of targets and environmental information they have sensed. The group structure may change dynamically and each group focuses on searching one target. All targets are supposed to be found finally. Obstacle avoidance is considered during the search process. Simulation compared with previous method demonstrates the adaptability, accuracy and efficiency of the proposed strategy in multiple targets searching.

  19. Knowledge-Base Application to Ground Moving Target Detection

    National Research Council Canada - National Science Library

    Adve, R

    2001-01-01

    This report summarizes a multi-year in-house effort to apply knowledge-base control techniques and advanced Space-Time Adaptive Processing algorithms to improve detection performance and false alarm...

  20. Directed energy deflection laboratory measurements of common space based targets

    Science.gov (United States)

    Brashears, Travis; Lubin, Philip; Hughes, Gary B.; Meinhold, Peter; Batliner, Payton; Motta, Caio; Madajian, Jonathan; Mercer, Whitaker; Knowles, Patrick

    2016-09-01

    We report on laboratory studies of the effectiveness of directed energy planetary defense as a part of the DE-STAR (Directed Energy System for Targeting of Asteroids and exploRation) program. DE-STAR and DE-STARLITE are directed energy "stand-off" and "stand-on" programs, respectively. These systems consist of a modular array of kilowatt-class lasers powered by photovoltaics, and are capable of heating a spot on the surface of an asteroid to the point of vaporization. Mass ejection, as a plume of evaporated material, creates a reactionary thrust capable of diverting the asteroid's orbit. In a series of papers, we have developed a theoretical basis and described numerical simulations for determining the thrust produced by material evaporating from the surface of an asteroid. In the DESTAR concept, the asteroid itself is used as the deflection "propellant". This study presents results of experiments designed to measure the thrust created by evaporation from a laser directed energy spot. We constructed a vacuum chamber to simulate space conditions, and installed a torsion balance that holds a common space target sample. The sample is illuminated with a fiber array laser with flux levels up to 60 MW/m2 , which allows us to simulate a mission level flux but on a small scale. We use a separate laser as well as a position sensitive centroid detector to readout the angular motion of the torsion balance and can thus determine the thrust. We compare the measured thrust to the models. Our theoretical models indicate a coupling coefficient well in excess of 100 μN/Woptical, though we assume a more conservative value of 80 μN/Woptical and then degrade this with an optical "encircled energy" efficiency of 0.75 to 60 μN/Woptical in our deflection modeling. Our measurements discussed here yield about 45 μN/Wabsorbed as a reasonable lower limit to the thrust per optical watt absorbed. Results vary depending on the material tested and are limited to measurements of 1 axis, so

  1. SPMK AND GRABCUT BASED TARGET EXTRACTION FROM HIGH RESOLUTION REMOTE SENSING IMAGES

    Directory of Open Access Journals (Sweden)

    W. Cui

    2016-06-01

    Full Text Available Target detection and extraction from high resolution remote sensing images is a basic and wide needed application. In this paper, to improve the efficiency of image interpretation, we propose a detection and segmentation combined method to realize semi-automatic target extraction. We introduce the dense transform color scale invariant feature transform (TC-SIFT descriptor and the histogram of oriented gradients (HOG & HSV descriptor to characterize the spatial structure and color information of the targets. With the k-means cluster method, we get the bag of visual words, and then, we adopt three levels’ spatial pyramid (SP to represent the target patch. After gathering lots of different kinds of target image patches from many high resolution UAV images, and using the TC-SIFT-SP and the multi-scale HOG & HSV feature, we constructed the SVM classifier to detect the target. In this paper, we take buildings as the targets. Experiment results show that the target detection accuracy of buildings can reach to above 90%. Based on the detection results which are a series of rectangle regions of the targets. We select the rectangle regions as candidates for foreground and adopt the GrabCut based and boundary regularized semi-auto interactive segmentation algorithm to get the accurate boundary of the target. Experiment results show its accuracy and efficiency. It can be an effective way for some special targets extraction.

  2. Spmk and Grabcut Based Target Extraction from High Resolution Remote Sensing Images

    Science.gov (United States)

    Cui, Weihong; Wang, Guofeng; Feng, Chenyi; Zheng, Yiwei; Li, Jonathan; Zhang, Yi

    2016-06-01

    Target detection and extraction from high resolution remote sensing images is a basic and wide needed application. In this paper, to improve the efficiency of image interpretation, we propose a detection and segmentation combined method to realize semi-automatic target extraction. We introduce the dense transform color scale invariant feature transform (TC-SIFT) descriptor and the histogram of oriented gradients (HOG) & HSV descriptor to characterize the spatial structure and color information of the targets. With the k-means cluster method, we get the bag of visual words, and then, we adopt three levels' spatial pyramid (SP) to represent the target patch. After gathering lots of different kinds of target image patches from many high resolution UAV images, and using the TC-SIFT-SP and the multi-scale HOG & HSV feature, we constructed the SVM classifier to detect the target. In this paper, we take buildings as the targets. Experiment results show that the target detection accuracy of buildings can reach to above 90%. Based on the detection results which are a series of rectangle regions of the targets. We select the rectangle regions as candidates for foreground and adopt the GrabCut based and boundary regularized semi-auto interactive segmentation algorithm to get the accurate boundary of the target. Experiment results show its accuracy and efficiency. It can be an effective way for some special targets extraction.

  3. Shared Representation of SAR Target and Shadow Based on Multilayer Auto-encoder

    Directory of Open Access Journals (Sweden)

    Sun Zhi-jun

    2013-06-01

    Full Text Available Automatic Target Recognition (ATR of Synthetic Aperture Radar (SAR image is investigated. A SAR feature extraction algorithm based on multilayer auto-encoder is proposed. The method makes use of a probabilistic neural network, Restricted Boltzmann Machine (RBM modeling probability distribution of environment. Through the formation of more expressive multilayer neural network, the deep learning model learns shared representation of the target and its shadow outline reflecting the target shape characteristics. Targets are classified automatically through two recognition models. The experiment results based on the MSTAR verify the effectiveness of proposed algorithm.

  4. Potential role of proton therapy in the treatment of pediatric medulloblastoma/primitive neuroectodermal tumors: reduction of the supratentorial target volume

    International Nuclear Information System (INIS)

    Miralbell, Raymond; Lomax, Anthony; Bortfeld, Thomas; Rouzaud, Michel; Carrie, Christian

    1997-01-01

    Purpose: One of the components of radiotherapy (RT) in medulloblastoma/primitive neuroectodermal tumors is the prophylactic irradiation of the whole brain (WBI). With the aim of reducing late neuropsychologic morbidity a CT-scan-based dosimetric study was undertaken in which treatment was confined mainly or exclusively to supratentorial sites considered at high risk for disease recurrence. Methods and Materials: A comparative dosimetric study is presented in which a three field (two laterals and one posterior) proton plan (spot scanning method) is compared with a two-field conventional WBI 6 MV x-ray plan, to a 6-field 'hand-made' 6 MV x-ray plan, and to a computer-optimized 9-field 'inverse' 15 MV x-ray plan. For favorable patients, 30 Gy were delivered to the ventricles and main cisterns, the subfrontal and subtemporal regions, and the posterior fossa. For the unfavorable patients, 10 Gy WBI preceded a boost to 30 Gy to the same treatment volume chosen for favorable patients. The dose distribution was evaluated with dose-volume histograms to examine the coverage of the targets as well as the dose to the nontarget brain and optical structures. In addition, the risks of radiation-related late neuropsychologic effects after WBI were collected from the literature and used to predict normal tissue complication probabilities (NTCPs) for an intelligence quotient deficit after treatment with photon or proton beams. Results: Proton beams succeeded better in reducing the dose to the brain hemispheres and eye than any of the photon plans. A 25.1% risk of an IQ score <90 was predicted after 30 Gy WBI. Almost a 10% drop in the predicted risk was observed when using proton beams in both favorable and unfavorable patients. However, predicted NTCPs for both optimized photon plans ('hand made' and 'inverse') were only slightly higher (0.3-2.5%) than those of proton beams. An age-modifying factor was introduced in the predictive NTCP model to assess for IQ differences in relation

  5. Laser-based target tracking using principal component descriptors

    CSIR Research Space (South Africa)

    Burke, Michael G

    2010-11-01

    Full Text Available ]. Here, supervised learning was applied to the problem of building a classifier for the detection of people. Their approach used AdaBoost to create a strong classifier by combining a set of weak classifiers. Their classifier consisted of 14... of classifiers based on the 14 features of [5] in the context of pedestrian detection. A better classifier, which uses AdaBoost to train a classifier using a probabilistic part-based model of geometric laser primitives in conjunction with omnidirectional...

  6. An improved distance-to-dose correlation for predicting bladder and rectum dose-volumes in knowledge-based VMAT planning for prostate cancer

    Science.gov (United States)

    Wall, Phillip D. H.; Carver, Robert L.; Fontenot, Jonas D.

    2018-01-01

    The overlap volume histogram (OVH) is an anatomical metric commonly used to quantify the geometric relationship between an organ at risk (OAR) and target volume when predicting expected dose-volumes in knowledge-based planning (KBP). This work investigated the influence of additional variables contributing to variations in the assumed linear DVH-OVH correlation for the bladder and rectum in VMAT plans of prostate patients, with the goal of increasing prediction accuracy and achievability of knowledge-based planning methods. VMAT plans were retrospectively generated for 124 prostate patients using multi-criteria optimization. DVHs quantified patient dosimetric data while OVHs quantified patient anatomical information. The DVH-OVH correlations were calculated for fractional bladder and rectum volumes of 30, 50, 65, and 80%. Correlations between potential influencing factors and dose were quantified using the Pearson product-moment correlation coefficient (R). Factors analyzed included the derivative of the OVH, prescribed dose, PTV volume, bladder volume, rectum volume, and in-field OAR volume. Out of the selected factors, only the in-field bladder volume (mean R  =  0.86) showed a strong correlation with bladder doses. Similarly, only the in-field rectal volume (mean R  =  0.76) showed a strong correlation with rectal doses. Therefore, an OVH formalism accounting for in-field OAR volumes was developed to determine the extent to which it improved the DVH-OVH correlation. Including the in-field factor improved the DVH-OVH correlation, with the mean R values over the fractional volumes studied improving from  -0.79 to  -0.85 and  -0.82 to  -0.86 for the bladder and rectum, respectively. A re-planning study was performed on 31 randomly selected database patients to verify the increased accuracy of KBP dose predictions by accounting for bladder and rectum volume within treatment fields. The in-field OVH led to significantly more precise

  7. Multiple local minima in IMRT optimization based on dose-volume criteria

    International Nuclear Information System (INIS)

    Wu Qiuwen; Mohan, Radhe

    2002-01-01

    Multiple local minima traps are known to exist in dose-volume and dose-response objective functions. Nevertheless, their presence and consequences are not considered impediments in finding satisfactory solutions in routine optimization of IMRT plans using gradient methods. However, there is often a concern that a significantly superior solution may exist unbeknownst to the planner and that the optimization process may not be able to reach it. We have investigated the soundness of the assumption that the presence of multiple minima traps can be ignored. To find local minima, we start the optimization process a large number of times with random initial intensities. We investigated whether the occurrence of local minima depends upon the choice of the objective function parameters and the number of variables and whether their existence is an impediment in finding a satisfactory solution. To learn about the behavior of multiple minima, we first used a symmetric cubic phantom containing a cubic target and an organ-at-risk surrounding it to optimize the beam weights of two pairs of parallel-opposed beams using a gradient technique. The phantom studies also served to test our software. Objective function parameters were chosen to ensure that multiple minima would exist. Data for 500 plans, optimized with random initial beam weights, were analyzed. The search process did succeed in finding the local minima and showed that the number of minima depends on the parameters of the objective functions. It was also found that the consequences of local minima depended on the number of beams. We further searched for the multiple minima in intensity-modulated treatment plans for a head-and-neck case and a lung case. In addition to the treatment plan scores and the dose-volume histograms, we examined the dose distributions and intensity patterns. We did not find any evidence that multiple local minima affect the outcome of optimization using gradient techniques in any clinically

  8. Simulation-based partial volume correction for dopaminergic PET imaging. Impact of segmentation accuracy

    Energy Technology Data Exchange (ETDEWEB)

    Rong, Ye; Winz, Oliver H. [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; Vernaleken, Ingo [University Hospital Aachen (Germany). Dept. of Psychiatry, Psychotherapy and Psychosomatics; Goedicke, Andreas [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; High Tech Campus, Philips Research Lab., Eindhoven (Netherlands); Mottaghy, Felix M. [University Hospital Aachen (Germany). Dept. of Nuclear Medicine; Maastricht University Medical Center (Netherlands). Dept. of Nuclear Medicine; Rota Kops, Elena [Forschungszentrum Juelich (Germany). Inst. of Neuroscience and Medicine-4

    2015-07-01

    Partial volume correction (PVC) is an essential step for quantitative positron emission tomography (PET). In the present study, PVELab, a freely available software, is evaluated for PVC in {sup 18}F-FDOPA brain-PET, with a special focus on the accuracy degradation introduced by various MR-based segmentation approaches. Methods Four PVC algorithms (M-PVC; MG-PVC; mMG-PVC; and R-PVC) were analyzed on simulated {sup 18}F-FDOPA brain-PET images. MR image segmentation was carried out using FSL (FMRIB Software Library) and SPM (Statistical Parametric Mapping) packages, including additional adaptation for subcortical regions (SPM{sub L}). Different PVC and segmentation combinations were compared with respect to deviations in regional activity values and time-activity curves (TACs) of the occipital cortex (OCC), caudate nucleus (CN), and putamen (PUT). Additionally, the PVC impact on the determination of the influx constant (K{sub i}) was assessed. Results Main differences between tissue-maps returned by three segmentation algorithms were found in the subcortical region, especially at PUT. Average misclassification errors in combination with volume reduction was found to be lowest for SPM{sub L} (PUT < 30%) and highest for FSL (PUT > 70%). Accurate recovery of activity data at OCC is achieved by M-PVC (apparent recovery coefficient varies between 0.99 and 1.10). The other three evaluated PVC algorithms have demonstrated to be more suitable for subcortical regions with MG-PVC and mMG-PVC being less prone to the largest tissue misclassification error simulated in this study. Except for M-PVC, quantification accuracy of K{sub i} for CN and PUT was clearly improved by PVC. Conclusions The regional activity value of PUT was appreciably overcorrected by most of the PVC approaches employing FSL or SPM segmentation, revealing the importance of accurate MR image segmentation for the presented PVC framework. The selection of a PVC approach should be adapted to the anatomical

  9. Target-Based Maintenance of Privacy Preserving Association Rules

    Science.gov (United States)

    Ahluwalia, Madhu V.

    2011-01-01

    In the context of association rule mining, the state-of-the-art in privacy preserving data mining provides solutions for categorical and Boolean association rules but not for quantitative association rules. This research fills this gap by describing a method based on discrete wavelet transform (DWT) to protect input data privacy while preserving…

  10. MRI/TRUS fusion software-based targeted biopsy: the new standard of care?

    Science.gov (United States)

    Manfredi, M; Costa Moretti, T B; Emberton, M; Villers, A; Valerio, M

    2015-09-01

    The advent of multiparametric MRI has made it possible to change the way in which prostate biopsy is done, allowing to direct biopsies to suspicious lesions rather than randomly. The subject of this review relates to a computer-assisted strategy, the MRI/US fusion software-based targeted biopsy, and to its performance compared to the other sampling methods. Different devices with different methods to register MR images to live TRUS are currently in use to allow software-based targeted biopsy. Main clinical indications of MRI/US fusion software-based targeted biopsy are re-biopsy in men with persistent suspicious of prostate cancer after first negative standard biopsy and the follow-up of patients under active surveillance. Some studies have compared MRI/US fusion software-based targeted versus standard biopsy. In men at risk with MRI-suspicious lesion, targeted biopsy consistently detects more men with clinically significant disease as compared to standard biopsy; some studies have also shown decreased detection of insignificant disease. Only two studies directly compared MRI/US fusion software-based targeted biopsy with MRI/US fusion visual targeted biopsy, and the diagnostic ability seems to be in favor of the software approach. To date, no study comparing software-based targeted biopsy against in-bore MRI biopsy is available. The new software-based targeted approach seems to have the characteristics to be added in the standard pathway for achieving accurate risk stratification. Once reproducibility and cost-effectiveness will be verified, the actual issue will be to determine whether MRI/TRUS fusion software-based targeted biopsy represents anadd-on test or a replacement to standard TRUS biopsy.

  11. Statistical model based gender prediction for targeted NGS clinical panels

    Directory of Open Access Journals (Sweden)

    Palani Kannan Kandavel

    2017-12-01

    The reference test dataset are being used to test the model. The sensitivity on predicting the gender has been increased from the current “genotype composition in ChrX” based approach. In addition, the prediction score given by the model can be used to evaluate the quality of clinical dataset. The higher prediction score towards its respective gender indicates the higher quality of sequenced data.

  12. Automated Threshold Selection for Template-Based Sonar Target Detection

    Science.gov (United States)

    2017-08-01

    detector performance. An adaptive clutter filter detector has been individually applied to three different sonar images varying in frequency and...like objects, unexploded ordnance, or other man-made debris. The approaches range from as general as possible to very specific. One general approach ...based approach . Each one uses a different model to reproduce three elements which are key to sonar ATR, highlight structure, seabed reverberation

  13. Hardware Accelerators Targeting a Novel Group Based Packet Classification Algorithm

    Directory of Open Access Journals (Sweden)

    O. Ahmed

    2013-01-01

    Full Text Available Packet classification is a ubiquitous and key building block for many critical network devices. However, it remains as one of the main bottlenecks faced when designing fast network devices. In this paper, we propose a novel Group Based Search packet classification Algorithm (GBSA that is scalable, fast, and efficient. GBSA consumes an average of 0.4 megabytes of memory for a 10 k rule set. The worst-case classification time per packet is 2 microseconds, and the preprocessing speed is 3 M rules/second based on an Xeon processor operating at 3.4 GHz. When compared with other state-of-the-art classification techniques, the results showed that GBSA outperforms the competition with respect to speed, memory usage, and processing time. Moreover, GBSA is amenable to implementation in hardware. Three different hardware implementations are also presented in this paper including an Application Specific Instruction Set Processor (ASIP implementation and two pure Register-Transfer Level (RTL implementations based on Impulse-C and Handel-C flows, respectively. Speedups achieved with these hardware accelerators ranged from 9x to 18x compared with a pure software implementation running on an Xeon processor.

  14. Thermally optimized lithium neutron producing target design for accelerator-based BNCT

    International Nuclear Information System (INIS)

    Park Shane; Joo Hyeong Min; Jang Byeong Ill; Jeun, Gyoodong; Kim Jong Kyung; Chai, Jong Seo

    2006-01-01

    In accelerator-based Boron Neutron Capture Therapy (BNCT), 7 Li(p,n) 7 Be reaction is prevalently used as a neutron source. However, lithium has a very low melting point and poor thermal conductivity. Thus lithium target needs an efficient cooling. In this study, ways of increasing proton beam diameter and slanting target are proposed to reduce the heat density of lithium target. Thermal analysis on the lithium target design shows that water cooling is feasible if the proton beam diameter and target slopes are in the available range of the contour plots generated from this study. On the basis of the thermal analysis, the prototype of target system was designed and manufactured. Full-model thermal analysis and temperature measuring experiment were subsequently performed. The calculated temperature distribution coincided with the contour plots and the experimental results. These results will be used in the manufacture of the prototype accelerator-based BNCT facility at Hanyang University. (author)

  15. A novel monolithic LEU foil target based on a PVD manufacturing process for 99Mo production via fission.

    Science.gov (United States)

    Hollmer, Tobias; Petry, Winfried

    2016-12-01

    99 Mo is the most widely used radioactive isotope in nuclear medicine. Its main production route is the fission of uranium. A major challenge for a reliable supply is the conversion from highly enriched uranium (HEU) to low enriched uranium (LEU). A promising candidate to realize this conversion is the cylindrical LEU irradiation target. The target consists of a uranium foil encapsulated between two coaxial aluminum cladding cylinders. This target allows a separate processing of the irradiated uranium foil and the cladding when recovering the 99 Mo. Thereby, both the costs and the volume of highly radioactive liquid waste are significantly reduced compared to conventional targets. The presented manufacturing process is based on the direct coating of the uranium on the inside of the outer cladding cylinder. This process was realized by a cylindrical magnetron enhanced physical vapor deposition (PVD) technique. The method features a highly automated process, a good quality of the resulting uranium foils and a high material utilization. Copyright © 2016 Elsevier Ltd. All rights reserved.

  16. A Multiobjective Game Approach with a Preferred Target Based on a Leader-Follower Decision Pattern

    Directory of Open Access Journals (Sweden)

    Neng-gang Xie

    2018-01-01

    Full Text Available We propose a multiobjective leader-follower game based on the Stackelberg model, where the designer’s preferred target is taken into account. Here, the preferred target is regarded as a leader and the other targets are regarded as followers. A partition method of strategy subspace is also given. Finally, a real-life example of the multiobjective optimization design of a Chinese arch dam named “Baihetan” is presented to demonstrate the effectiveness of our proposed method.

  17. Accelerating Time-Varying Hardware Volume Rendering Using TSP Trees and Color-Based Error Metrics

    Science.gov (United States)

    Ellsworth, David; Chiang, Ling-Jen; Shen, Han-Wei; Kwak, Dochan (Technical Monitor)

    2000-01-01

    This paper describes a new hardware volume rendering algorithm for time-varying data. The algorithm uses the Time-Space Partitioning (TSP) tree data structure to identify regions within the data that have spatial or temporal coherence. By using this coherence, the rendering algorithm can improve performance when the volume data is larger than the texture memory capacity by decreasing the amount of textures required. This coherence can also allow improved speed by appropriately rendering flat-shaded polygons instead of textured polygons, and by not rendering transparent regions. To reduce the polygonization overhead caused by the use of the hierarchical data structure, we introduce an optimization method using polygon templates. The paper also introduces new color-based error metrics, which more accurately identify coherent regions compared to the earlier scalar-based metrics. By showing experimental results from runs using different data sets and error metrics, we demonstrate that the new methods give substantial improvements in volume rendering performance.

  18. An evaluation of volume-based morphometry for prediction of mild cognitive impairment and Alzheimer's disease

    Directory of Open Access Journals (Sweden)

    Daniel Schmitter

    2015-01-01

    Full Text Available Voxel-based morphometry from conventional T1-weighted images has proved effective to quantify Alzheimer's disease (AD related brain atrophy and to enable fairly accurate automated classification of AD patients, mild cognitive impaired patients (MCI and elderly controls. Little is known, however, about the classification power of volume-based morphometry, where features of interest consist of a few brain structure volumes (e.g. hippocampi, lobes, ventricles as opposed to hundreds of thousands of voxel-wise gray matter concentrations. In this work, we experimentally evaluate two distinct volume-based morphometry algorithms (FreeSurfer and an in-house algorithm called MorphoBox for automatic disease classification on a standardized data set from the Alzheimer's Disease Neuroimaging Initiative. Results indicate that both algorithms achieve classification accuracy comparable to the conventional whole-brain voxel-based morphometry pipeline using SPM for AD vs elderly controls and MCI vs controls, and higher accuracy for classification of AD vs MCI and early vs late AD converters, thereby demonstrating the potential of volume-based morphometry to assist diagnosis of mild cognitive impairment and Alzheimer's disease.

  19. Correlation-Based Tracking of Multiple Targets With Hierarchical Layered Structure.

    Science.gov (United States)

    Cao, Xianbin; Jiang, Xiaolong; Li, Xiaomei; Yan, Pingkun

    2018-01-01

    Visual target tracking is one of the most important research areas in the field of computer vision. Within this realm, multiple targets tracking (MTT) under complicated scene stands out for its great availability in real life applications, such as urban traffic surveillance and sports video analysis. However, in MTT, main difficulties arise from large variation in target saliency and significant motion heterogeneity, which may result in the failure of tracking weak targets. To tackle this challenge, a novel hierarchical layered tracking structure is proposed to perform tracking sequentially layer-by-layer. Upon this layered structure, we establish an intertarget mutual assistance mechanism on basis of intertarget correlation exploited among targets. The tracking results of a subset of targets can be utilized as additional prior information for tracking other targets. Specifically, a nonlinear motion model as well as a target interaction model basing on the intertarget correlation are proposed to effectively estimate the possible target region-of-interest to facilitate the prediction-based tracking. Moreover, the concept of motion entropy is introduced to quantitatively measure the degree of motion heterogeneity within the tracking scene for layer construction. Compared to other existing methods, extensive experiments demonstrated that the proposed method is capable of achieving higher tracking performance in complicated scenes, where targets are characterized with great heterogeneity.

  20. Influence of different contributions of scatter and attenuation on the threshold values in contrast-based algorithms for volume segmentation.

    Science.gov (United States)

    Matheoud, Roberta; Della Monica, Patrizia; Secco, Chiara; Loi, Gianfranco; Krengli, Marco; Inglese, Eugenio; Brambilla, Marco

    2011-01-01

    The aim of this work is to evaluate the role of different amount of attenuation and scatter on FDG-PET image volume segmentation using a contrast-oriented method based on the target-to-background (TB) ratio and target dimensions. A phantom study was designed employing 3 phantom sets, which provided a clinical range of attenuation and scatter conditions, equipped with 6 spheres of different volumes (0.5-26.5 ml). The phantoms were: (1) the Hoffman 3-dimensional brain phantom, (2) a modified International Electro technical Commission (IEC) phantom with an annular ring of water bags of 3 cm thickness fit over the IEC phantom, and (3) a modified IEC phantom with an annular ring of water bags of 9 cm. The phantoms cavities were filled with a solution of FDG at 5.4 kBq/ml activity concentration, and the spheres with activity concentration ratios of about 16, 8, and 4 times the background activity concentration. Images were acquired with a Biograph 16 HI-REZ PET/CT scanner. Thresholds (TS) were determined as a percentage of the maximum intensity in the cross section area of the spheres. To reduce statistical fluctuations a nominal maximum value is calculated as the mean from all voxel > 95%. To find the TS value that yielded an area A best matching the true value, the cross section were auto-contoured in the attenuation corrected slices varying TS in step of 1%, until the area so determined differed by less than 10 mm² versus its known physical value. Multiple regression methods were used to derive an adaptive thresholding algorithm and to test its dependence on different conditions of attenuation and scatter. The errors of scatter and attenuation correction increased with increasing amount of attenuation and scatter in the phantoms. Despite these increasing inaccuracies, PET threshold segmentation algorithms resulted not influenced by the different condition of attenuation and scatter. The test of the hypothesis of coincident regression lines for the three phantoms used

  1. A new method of small target detection based on neural network

    Science.gov (United States)

    Hu, Jing; Hu, Yongli; Lu, Xinxin

    2018-02-01

    The detection and tracking of moving dim target in infrared image have been an research hotspot for many years. The target in each frame of images only occupies several pixels without any shape and structure information. Moreover, infrared small target is often submerged in complicated background with low signal-to-clutter ratio, making the detection very difficult. Different backgrounds exhibit different statistical properties, making it becomes extremely complex to detect the target. If the threshold segmentation is not reasonable, there may be more noise points in the final detection, which is unfavorable for the detection of the trajectory of the target. Single-frame target detection may not be able to obtain the desired target and cause high false alarm rate. We believe the combination of suspicious target detection spatially in each frame and temporal association for target tracking will increase reliability of tracking dim target. The detection of dim target is mainly divided into two parts, In the first part, we adopt bilateral filtering method in background suppression, after the threshold segmentation, the suspicious target in each frame are extracted, then we use LSTM(long short term memory) neural network to predict coordinates of target of the next frame. It is a brand-new method base on the movement characteristic of the target in sequence images which could respond to the changes in the relationship between past and future values of the values. Simulation results demonstrate proposed algorithm can effectively predict the trajectory of the moving small target and work efficiently and robustly with low false alarm.

  2. Maneuvering Target Detection Based on JRC System in Gaussian and Non-Gaussian Clutter

    Directory of Open Access Journals (Sweden)

    Yu Yao

    2015-01-01

    Full Text Available Aimed at the problem of detecting maneuvering targets in the Gaussian and sea clutter environments and based on the established motion state model, this paper proposed a new scheme that uses a joint radar-communication (JRC system with Kalman filter to accurately detect the target with the generalized likelihood ratio test (GLRT theory and a constant false alarm rate (CFAR based threshold. Also, the theoretical threshold and probability function of GLRT target detection based on CFAR were given. Moreover, target detection probability of the new JRC system in Weibull and K distribution clutter is deduced. In addition to theoretical considerations, simulations and measurement results of the new JRC systems demonstrate excellent detection performance for maneuvering targets in the Weibull and K distribution channel.

  3. Intensity modulated radiation therapy (IMRT: differences in target volumes and improvement in clinically relevant doses to small bowel in rectal carcinoma

    Directory of Open Access Journals (Sweden)

    Delclos Marc E

    2011-06-01

    covered by classic bony landmark-derived fields, without incurring penalty with respect to adjacent organs-at-risk. Conclusions For rectal carcinoma, IMRT, compared to 3DCRT, yielded plans superior with respect to target coverage, homogeneity, and conformality, while lowering dose to adjacent organs-at-risk. This is achieved despite treating larger volumes, raising the possibility of a clinically-relevant improvement in the therapeutic ratio through the use of IMRT with a belly-board apparatus.

  4. Web-based volume slicer for 3D electron-microscopy data from EMDB.

    Science.gov (United States)

    Salavert-Torres, José; Iudin, Andrii; Lagerstedt, Ingvar; Sanz-García, Eduardo; Kleywegt, Gerard J; Patwardhan, Ardan

    2016-05-01

    We describe the functionality and design of the Volume slicer - a web-based slice viewer for EMDB entries. This tool uniquely provides the facility to view slices from 3D EM reconstructions along the three orthogonal axes and to rapidly switch between them and navigate through the volume. We have employed multiple rounds of user-experience testing with members of the EM community to ensure that the interface is easy and intuitive to use and the information provided is relevant. The impetus to develop the Volume slicer has been calls from the EM community to provide web-based interactive visualisation of 2D slice data. This would be useful for quick initial checks of the quality of a reconstruction. Again in response to calls from the community, we plan to further develop the Volume slicer into a fully-fledged Volume browser that provides integrated visualisation of EMDB and PDB entries from the molecular to the cellular scale. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  5. Evaluating gaze-based interface tools to facilitate point-and-select tasks with small targets

    DEFF Research Database (Denmark)

    Skovsgaard, Henrik; Mateo, Julio C.; Hansen, John Paulin

    2011-01-01

    Gaze interaction affords hands-free control of computers. Pointing to and selecting small targets using gaze alone is difficult because of the limited accuracy of gaze pointing. This is the first experimental comparison of gaze-based interface tools for small-target (e.g. <12 × 12 pixels) point-a...

  6. The Cost of Event-Based Prospective Memory: Salient Target Events

    Science.gov (United States)

    Smith, Rebekah E.; Hunt, R. Reed; McVay, Jennifer C.; McConnell, Melissa D.

    2007-01-01

    Evidence has begun to accumulate showing that successful performance of event-based prospective memory (PM) comes at a cost to other ongoing activities. The current study builds on previous work by examining the cost associated with PM when the target event is salient. Target salience is among the criteria for automatic retrieval of intentions…

  7. Structure-based drug design approach to target toll-like receptor ...

    African Journals Online (AJOL)

    Figure 1: Structure-based drug design pipeline modified from Grey and Thompson [3]. Table 1: Examples of potential targets whose three-dimensional structures were determined using NMR, x-ray crystallography or homology modeling. Name of target. Technique. Reference. Human transforming growth factor alpha. NMR.

  8. Near-Millimeter Wave Technology Base Study: Volume I. Propagation and Target/Background Characteristics

    Science.gov (United States)

    1979-11-01

    and whenlookng hrouh hevy umuls cludsor rin 1R. L. Plamnbeck, Measurements of Atmospheric Altitnuation near showers . The theoretical curt)e was...reflectance and transmittance paony (1941) "M. D. Blue and S. Perkowltz, Rflectluity of Common Materiala in the Submillim’ter Region, IEEE Trmns

  9. A cache-friendly sampling strategy for texture-based volume rendering on GPU

    Directory of Open Access Journals (Sweden)

    Junpeng Wang

    2017-06-01

    Full Text Available The texture-based volume rendering is a memory-intensive algorithm. Its performance relies heavily on the performance of the texture cache. However, most existing texture-based volume rendering methods blindly map computational resources to texture memory and result in incoherent memory access patterns, causing low cache hit rates in certain cases. The distance between samples taken by threads of an atomic scheduling unit (e.g. a warp of 32 threads in CUDA of the GPU is a crucial factor that affects the texture cache performance. Based on this fact, we present a new sampling strategy, called Warp Marching, for the ray-casting algorithm of texture-based volume rendering. The effects of different sample organizations and different thread-pixel mappings in the ray-casting algorithm are thoroughly analyzed. Also, a pipeline manner color blending approach is introduced and the power of warp-level GPU operations is leveraged to improve the efficiency of parallel executions on the GPU. In addition, the rendering performance of the Warp Marching is view-independent, and it outperforms existing empty space skipping techniques in scenarios that need to render large dynamic volumes in a low resolution image. Through a series of micro-benchmarking and real-life data experiments, we rigorously analyze our sampling strategies and demonstrate significant performance enhancements over existing sampling methods.

  10. New Technology-Based Firms in the New Millennium - Volume III

    NARCIS (Netherlands)

    During, W.E.; Oakey, R.; Kauser, S.

    2004-01-01

    This tenth volume from the annual International High Technology Small Firms Conference adds to substantial specialist work on growth problems of New Technology Based Firms (NTBFs). This series represents a clear case where the whole is greater than the sum of its individual parts and, in view of

  11. Central Issues in the Use of Computer-Based Materials for High Volume Entrepreneurship Education

    Science.gov (United States)

    Cooper, Billy

    2007-01-01

    This article discusses issues relating to the use of computer-based learning (CBL) materials for entrepreneurship education at university level. It considers CBL as a means of addressing the increased volume and range of provision required in the current context. The issues raised in this article have importance for all forms of computer-based…

  12. SOLVENT-BASED TO WATERBASED ADHESIVE-COATED SUBSTRATE RETROFIT - VOLUME II: PROCESS OVERVIEW

    Science.gov (United States)

    This volume presents initial results of a study to identify the issues and barriers associated with retrofitting existing solvent-based equipment to accept waterbased adhesives as part of an EPA effort to improve equipment cleaning in the coated and laminated substrate manufactur...

  13. Novel Apigenin Based Small Molecule that Targets Snake Venom Metalloproteases

    Science.gov (United States)

    Anusha, Sebastian; Hemshekhar, Mahadevappa; Chandra Nayaka, Siddaiah; Kemparaju, Kempaiah; Basappa; Girish, Kesturu S.; Rangappa, Kanchugarakoppal S.

    2014-01-01

    The classical antivenom therapy has appreciably reduced snakebite mortality rate and thus is the only savior drug available. Unfortunately, it considerably fails to shield the viper bite complications like hemorrhage, local tissue degradation and necrosis responsible for severe morbidity. Moreover, the therapy is also tagged with limitations including anaphylaxis, serum sickness and poor availability. Over the last decade, snake venom metalloproteases (SVMPs) are reported to be the primary component responsible for hemorrhage and tissue degradation at bitten site. Thus, antivenom inability to offset viper venom-induced local toxicity has been a basis for an insistent search for SVMP inhibitors. Here we report the inhibitory effect of compound 5d, an apigenin based molecule against SVMPs both in silico and in vivo. Several apigenin analogues are synthesized using multicomponent Ugi reactions. Among them, compound 5d effectively abrogated Echis carinatus (EC) venom-induced local hemorrhage, tissue necrosis and myotoxicity in a dose dependant fashion. The histopathological study further conferred effective inhibition of basement membrane degradation, and accumulation of inflammatory leucocytes at the site of EC venom inoculation. The compound also protected EC venom-induced fibrin and fibrinogen degradation. The molecular docking of compound 5d and bothropasin demonstrated the direct interaction of hydroxyl group of compound with Glu146 present in hydrophobic pocket of active site and does not chelate Zn2+. Hence, it is concluded that compound 5d could be a potent agent in viper bite management. PMID:25184206

  14. Gamma Knife irradiation method based on dosimetric controls to target small areas in rat brains

    International Nuclear Information System (INIS)

    Constanzo, Julie; Paquette, Benoit; Charest, Gabriel; Masson-Côté, Laurence; Guillot, Mathieu

    2015-01-01

    Purpose: Targeted and whole-brain irradiation in humans can result in significant side effects causing decreased patient quality of life. To adequately investigate structural and functional alterations after stereotactic radiosurgery, preclinical studies are needed. The purpose of this work is to establish a robust standardized method of targeted irradiation on small regions of the rat brain. Methods: Euthanized male Fischer rats were imaged in a stereotactic bed, by computed tomography (CT), to estimate positioning variations relative to the bregma skull reference point. Using a rat brain atlas and the stereotactic bregma coordinates obtained from CT images, different regions of the brain were delimited and a treatment plan was generated. A single isocenter treatment plan delivering ≥100 Gy in 100% of the target volume was produced by Leksell GammaPlan using the 4 mm diameter collimator of sectors 4, 5, 7, and 8 of the Gamma Knife unit. Impact of positioning deviations of the rat brain on dose deposition was simulated by GammaPlan and validated with dosimetric measurements. Results: The authors’ results showed that 90% of the target volume received 100 ± 8 Gy and the maximum of deposited dose was 125 ± 0.7 Gy, which corresponds to an excellent relative standard deviation of 0.6%. This dose deposition calculated with GammaPlan was validated with dosimetric films resulting in a dose-profile agreement within 5%, both in X- and Z-axes. Conclusions: The authors’ results demonstrate the feasibility of standardizing the irradiation procedure of a small volume in the rat brain using a Gamma Knife

  15. Expanding the range of 'druggable' targets with natural product-based libraries: an academic perspective.

    Science.gov (United States)

    Bauer, Renato A; Wurst, Jacqueline M; Tan, Derek S

    2010-06-01

    Existing drugs address a relatively narrow range of biological targets. As a result, libraries of drug-like molecules have proven ineffective against a variety of challenging targets, such as protein-protein interactions, nucleic acid complexes, and antibacterial modalities. In contrast, natural products are known to be effective at modulating such targets, and new libraries are being developed based on underrepresented scaffolds and regions of chemical space associated with natural products. This has led to several recent successes in identifying new chemical probes that address these challenging targets. Copyright 2010 Elsevier Ltd. All rights reserved.

  16. Measurement of renal function in a kidney donor: a comparison of creatinine-based and volume-based GFRs

    International Nuclear Information System (INIS)

    Choi, Don Kyoung; Choi, See Min; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han-Yong; Jeon, Hwang Gyun; Park, Bong Hee

    2015-01-01

    We aimed to evaluate the performance of various GFR estimates compared with direct measurement of GFR (dGFR). We also sought to create a new formula for volume-based GFR (new-vGFR) using kidney volume determined by CT. GFR was measured using creatinine-based methods (MDRD, the Cockcroft-Gault equation, CKD-EPI formula, and the Mayo clinic formula) and the Herts method, which is volume-based (vGFR). We compared performance between GFR estimates and created a new vGFR model by multiple linear regression analysis. Among the creatinine-based GFR estimates, the MDRD and C-G equations were similarly associated with dGFR (correlation and concordance coefficients of 0.359 and 0.369 and 0.354 and 0.318, respectively). We developed the following new kidney volume-based GFR formula: 217.48-0.39XA + 0.25XW-0.46XH-54.01XsCr + 0.02XV-19.89 (if female) (A = age, W = weight, H = height, sCr = serum creatinine level, V = total kidney volume). The MDRD and CKD-EPI had relatively better accuracy than the other creatinine-based methods (30.7 % vs. 32.3 % within 10 % and 78.0 % vs. 73.0 % within 30 %, respectively). However, the new-vGFR formula had the most accurate results among all of the analyzed methods (37.4 % within 10 % and 84.6 % within 30 %). The new-vGFR can replace dGFR or creatinine-based GFR for assessing kidney function in donors and healthy individuals. (orig.)

  17. Measurement of renal function in a kidney donor: a comparison of creatinine-based and volume-based GFRs

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Don Kyoung; Choi, See Min; Jeong, Byong Chang; Seo, Seong Il; Jeon, Seong Soo; Lee, Hyun Moo; Choi, Han-Yong; Jeon, Hwang Gyun [Sungkyunkwan University School of Medicine, Department of Urology, Samsung Medical Center, Seoul (Korea, Republic of); Park, Bong Hee [The Catholic University of Korea College of Medicine, Department of Urology, Incheon St. Mary' s Hospital, Seoul (Korea, Republic of)

    2015-11-15

    We aimed to evaluate the performance of various GFR estimates compared with direct measurement of GFR (dGFR). We also sought to create a new formula for volume-based GFR (new-vGFR) using kidney volume determined by CT. GFR was measured using creatinine-based methods (MDRD, the Cockcroft-Gault equation, CKD-EPI formula, and the Mayo clinic formula) and the Herts method, which is volume-based (vGFR). We compared performance between GFR estimates and created a new vGFR model by multiple linear regression analysis. Among the creatinine-based GFR estimates, the MDRD and C-G equations were similarly associated with dGFR (correlation and concordance coefficients of 0.359 and 0.369 and 0.354 and 0.318, respectively). We developed the following new kidney volume-based GFR formula: 217.48-0.39XA + 0.25XW-0.46XH-54.01XsCr + 0.02XV-19.89 (if female) (A = age, W = weight, H = height, sCr = serum creatinine level, V = total kidney volume). The MDRD and CKD-EPI had relatively better accuracy than the other creatinine-based methods (30.7 % vs. 32.3 % within 10 % and 78.0 % vs. 73.0 % within 30 %, respectively). However, the new-vGFR formula had the most accurate results among all of the analyzed methods (37.4 % within 10 % and 84.6 % within 30 %). The new-vGFR can replace dGFR or creatinine-based GFR for assessing kidney function in donors and healthy individuals. (orig.)

  18. Intra-tumour 18F-FDG uptake heterogeneity decreases the reliability on target volume definition with positron emission tomography/computed tomography imaging.

    Science.gov (United States)

    Dong, Xinzhe; Wu, Peipei; Sun, Xiaorong; Li, Wenwu; Wan, Honglin; Yu, Jinming; Xing, Ligang

    2015-06-01

    This study aims to explore whether the intra-tumour (18) F-fluorodeoxyglucose (FDG) uptake heterogeneity affects the reliability of target volume definition with FDG positron emission tomography/computed tomography (PET/CT) imaging for nonsmall cell lung cancer (NSCLC) and squamous cell oesophageal cancer (SCEC). Patients with NSCLC (n = 50) or SCEC (n = 50) who received (18)F-FDG PET/CT scanning before treatments were included in this retrospective study. Intra-tumour FDG uptake heterogeneity was assessed by visual scoring, the coefficient of variation (COV) of the standardised uptake value (SUV) and the image texture feature (entropy). Tumour volumes (gross tumour volume (GTV)) were delineated on the CT images (GTV(CT)), the fused PET/CT images (GTV(PET-CT)) and the PET images, using a threshold at 40% SUV(max) (GTV(PET40%)) or the SUV cut-off value of 2.5 (GTV(PET2.5)). The correlation between the FDG uptake heterogeneity parameters and the differences in tumour volumes among GTV(CT), GTV(PET-CT), GTV(PET40%) and GTV(PET2.5) was analysed. For both NSCLC and SCEC, obvious correlations were found between uptake heterogeneity, SUV or tumour volumes. Three types of heterogeneity parameters were consistent and closely related to each other. Substantial differences between the four methods of GTV definition were found. The differences between the GTV correlated significantly with PET heterogeneity defined with the visual score, the COV or the textural feature-entropy for NSCLC and SCEC. In tumours with a high FDG uptake heterogeneity, a larger GTV delineation difference was found. Advance image segmentation algorithms dealing with tracer uptake heterogeneity should be incorporated into the treatment planning system. © 2015 The Royal Australian and New Zealand College of Radiologists.

  19. Re-irradiation after gross total resection of recurrent glioblastoma. Spatial pattern of recurrence and a review of the literature as a basis for target volume definition

    Energy Technology Data Exchange (ETDEWEB)

    Straube, Christoph; Elpula, Greeshma [Technische Universitaet Muenchen (TUM), Department of Radiation Oncology, Klinikum rechts der Isar, Muenchen (Germany); Gempt, Jens; Gerhardt, Julia; Meyer, Bernhard [Technische Universitaet Muenchen (TUM), Department of Neurosurgery, Klinikum rechts der Isar, Muenchen (Germany); Bette, Stefanie; Zimmer, Claus [Technische Universitaet Muenchen (TUM), Department of Neuroradiology, Klinikum rechts der Isar, Muenchen (Germany); Schmidt-Graf, Friederike [Technische Universitaet Muenchen (TUM), Department of Neurology, Klinikum rechts der Isar, Muenchen (Germany); Combs, Stephanie E. [Technische Universitaet Muenchen (TUM), Department of Radiation Oncology, Klinikum rechts der Isar, Muenchen (Germany); Helmholtz Zentrum Muenchen, Institute for Innovative Radiotherapy (iRT), Department of Radiation Sciences (DRS), Oberschleissheim (Germany)

    2017-11-15

    Currently, patients with gross total resection (GTR) of recurrent glioblastoma (rGBM) undergo adjuvant chemotherapy or are followed up until progression. Re-irradiation, as one of the most effective treatments in macroscopic rGBM, is withheld in this situation, as uncertainties about the pattern of re-recurrence, the target volume, and also the efficacy of early re-irradiation after GTR exist. Imaging and clinical data from 26 consecutive patients with GTR of rGBM were analyzed. The spatial pattern of recurrences was analyzed according to the RANO-HGG criteria (''response assessment in neuro-oncology criteria for high-grade gliomas''). Progression-free (PFS) and overall survival (OS) were analyzed by the Kaplan-Meier method. Furthermore, a systematic review was performed in PubMed. All but 4 patients underwent adjuvant chemotherapy after GTR. Progression was diagnosed in 20 of 26 patients and 70% of recurrent tumors occurred adjacent to the resection cavity. The median extension beyond the edge of the resection cavity was 20 mm. Median PFS was 6 months; OS was 12.8 months. We propose a target volume containing the resection cavity and every contrast enhancing lesion as the gross tumor volume (GTV), a spherical margin of 5-10 mm to generate the clinical target volume (CTV), and a margin of 1-3 mm to generate the planning target volume (PTV). Re-irradiation of this volume is deemed to be safe and likely to prolong PFS. Re-irradiation is worth considering also after GTR, as the volumes that need to be treated are limited and re-irradiation has already proven to be a safe treatment option in general. The strategy of early re-irradiation is currently being tested within the GlioCave/NOA 17/Aro 2016/03 trial. (orig.) [German] Patienten mit einem rezidivierten Glioblastom (rGBM) werden, wenn eine komplette Resektion (GTR) des makroskopischen Rezidivs durchgefuehrt wurde, aktuell meist systemisch adjuvant behandelt oder einer engmaschigen Nachsorge

  20. In silico structure-based approaches to discover protein-protein interaction-targeting drugs.

    Science.gov (United States)

    Shin, Woong-Hee; Christoffer, Charles W; Kihara, Daisuke

    2017-12-01

    A core concept behind modern drug discovery is finding a small molecule that modulates a function of a target protein. This concept has been successfully applied since the mid-1970s. However, the efficiency of drug discovery is decreasing because the druggable target space in the human proteome is limited. Recently, protein-protein interaction (PPI) has been identified asan emerging target space for drug discovery. PPI plays a pivotal role in biological pathways including diseases. Current human interactome research suggests that the number of PPIs is between 130,000 and 650,000, and only a small number of them have been targeted as drug targets. For traditional drug targets, in silico structure-based methods have been successful in many cases. However, their performance suffers on PPI interfaces because PPI interfaces are different in five major aspects: From a geometric standpoint, they have relatively large interface regions, flat geometry, and the interface surface shape tends to fluctuate upon binding. Also, their interactions are dominated by hydrophobic atoms, which is different from traditional binding-pocket-targeted drugs. Finally, PPI targets usually lack natural molecules that bind to the target PPI interface. Here, we first summarize characteristics of PPI interfaces and their known binders. Then, we will review existing in silico structure-based approaches for discovering small molecules that bind to PPI interfaces. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Comprehensive data base of high-level nuclear waste glasses: September 1987 status report: Volume 2, Additional appendices

    Energy Technology Data Exchange (ETDEWEB)

    Kindle, C.H.; Kreiter, M.R.

    1987-12-01

    The Materials Characterization Center (MCC) is assembling a comprehensive data base (CDB) of experimental data collected for high-level nuclear waste package components. The status of the CDB is summarized in Volume I of this report. Volume II contains appendices that present data from the data base and an evaluation of glass durability models applied to the data base.

  2. 77 FR 59458 - Regulation of Fuels and Fuel Additives: 2013 Biomass-Based Diesel Renewable Fuel Volume

    Science.gov (United States)

    2012-09-27

    ... 80 Regulation of Fuels and Fuel Additives: 2013 Biomass-Based Diesel Renewable Fuel Volume; Final...] RIN 2060-AR55 Regulation of Fuels and Fuel Additives: 2013 Biomass-Based Diesel Renewable Fuel Volume... biomass-based diesel to be used in setting annual percentage standards under the renewable fuel standard...

  3. Evidence-Based Thresholds for the Volume-Value Relationship in Adolescent Idiopathic Scoliosis: Outcomes and Economies of Scale.

    Science.gov (United States)

    Navarro, Sergio M; Ramkumar, Prem N; Egger, Anthony C; Goodwin, Ryan C

    Increased surgeon and hospital volume has been associated with improved patient outcomes and cost effectiveness for adolescent idiopathic scoliosis (AIS). However, no evidence-based thresholds that clarify the volume at which these strata occur exist. The objective of this study was to establish statistically meaningful thresholds that define high-volume surgeons and hospitals performing spinal fusion for AIS from those that are low volume with respect to length of stay (LOS) and cost. Using 3,224 patients undergoing spinal fusion for AIS from an administrative database, we created and applied four models using stratum-specific likelihood ratio (SSLR) analysis of a receiver operating characteristic (ROC) curve. We generated four sets of thresholds predictive of adverse outcomes, namely, increased cost and LOS, for both surgeon and hospital volume. For both LOS and cost, surgeon volume produced the same strata with low volume identified as 0-5 annual surgeries and high as greater than 5. LOS and cost decreased significantly (p < .05) between volume strata. For hospital volume in terms of LOS, low volume was identified as 0-10 annual surgeries and high as greater than 10; in terms of cost, low volume was identified as 0-15 annual surgeries and high as greater than 15. LOS decreased significantly (p < .05) and cost was $1,500 less but not statistically significant between volume strata for hospital volume. Our study of risk-based volume stratification established a direct volume-value relationship for surgeons and hospitals performing fusion for AIS. A meaningful threshold for low- and high-volume surgeons was established at 5 annual surgeries, but no consensus or clinically meaningful conclusion was reached for hospitals, although the threshold approached 10-15 annual surgeries. This analysis should aid patients, surgeons, and administration reach value-based decisions in the optimal delivery of pediatric spinal fusion for AIS. Copyright © 2017 Scoliosis Research

  4. A chest-shape target automatic detection method based on Deformable Part Models

    Science.gov (United States)

    Zhang, Mo; Jin, Weiqi; Li, Li

    2016-10-01

    Automatic weapon platform is one of the important research directions at domestic and overseas, it needs to accomplish fast searching for the object to be shot under complex background. Therefore, fast detection for given target is the foundation of further task. Considering that chest-shape target is common target of shoot practice, this paper treats chestshape target as the target and studies target automatic detection method based on Deformable Part Models. The algorithm computes Histograms of Oriented Gradient(HOG) features of the target and trains a model using Latent variable Support Vector Machine(SVM); In this model, target image is divided into several parts then we can obtain foot filter and part filters; Finally, the algorithm detects the target at the HOG features pyramid with method of sliding window. The running time of extracting HOG pyramid with lookup table can be shorten by 36%. The result indicates that this algorithm can detect the chest-shape target in natural environments indoors or outdoors. The true positive rate of detection reaches 76% with many hard samples, and the false positive rate approaches 0. Running on a PC (Intel(R)Core(TM) i5-4200H CPU) with C++ language, the detection time of images with the resolution of 640 × 480 is 2.093s. According to TI company run library about image pyramid and convolution for DM642 and other hardware, our detection algorithm is expected to be implemented on hardware platform, and it has application prospect in actual system.

  5. ANALISIS SEGMENTASI, TARGETING, POSITIONING (STP) TERHADAP PENINGKATAN VOLUME PENJUALAN PADA RUMAH GRIYA MULYA ASRI DI KOTA MAKASSAR

    OpenAIRE

    Fitri _

    2017-01-01

    Volume at Griya Mulya Asri House In Makassar City. Guided by DR.Hj.Herminawati Abubakar., S.E., M.M and DR.Haeruddin Saleh., S.E., M.SiHome is a basic human need other than clothing and food. The increasing housing demand for Makassar residents encourages housing developers to provide more viable alternative housing solutions. Griya Mulya Asri Housing Estate is one of the best alternative choice for people who want a relaxed atmosphere amidst the urban bustle. Griya Mulya Asri Housing is very...

  6. Hardware in the Loop Implementation of Adaptive Vision Based Guidance Law for Ground Target Tracking

    Science.gov (United States)

    2008-12-01

    LIST OF FIGURES Figure 1. NPS Small UAV, Sig Rascal ................................................................. 2 Figure 2. Conceptual...NPS) to build a Vision Based Target Tracking (VBTT) simulator system in a laboratory environment. Figure 1. NPS Small UAV, Sig Rascal This

  7. AN AUTOMATIC FEATURE BASED MODEL FOR CELL SEGMENTATION FROM CONFOCAL MICROSCOPY VOLUMES

    OpenAIRE

    Delibaltov, Diana; Ghosh, Pratim; Veeman, Michael; Smith, William; Manjunath, B.S.

    2011-01-01

    We present a model for the automated segmentation of cells from confocal microscopy volumes of biological samples. The segmentation task for these images is exceptionally challenging due to weak boundaries and varying intensity during the imaging process. To tackle this, a two step pruning process based on the Fast Marching Method is first applied to obtain an over-segmented image. This is followed by a merging step based on an effective feature representation. The algorithm is applied on two...

  8. Infrared small target detection method based on local threshold attenuation of constant false alarm

    Science.gov (United States)

    Yu, Ke-feng; Shi, Zhi-guang; Lu, Xin-ping

    2016-03-01

    In the infrared small target detection system, CFAR (Constant False Alarm Rate) is a commonly used technology, but in the traditional single frame detection method, detection rate is requested to be improved while the false alarm rate is increasing. This paper proposes a threshold attenuation CFAR detection method based on Gauss distribution. After the preprocessing of infrared images, we came into the designing of CFAR detector based on Gauss distribution. According to the previous frame target location and attenuation of local threshold, the detection rate of the target neighbourhood can be improved to obtain the current target location. The experimental results show that the proposed method can effectively control the threshold, and under the precondition that the background clutter was suppressed by the global low false alarm rate, it can improve the local detection rate and reduce the probability of target loss.

  9. A finite volume method for cylindrical heat conduction problems based on local analytical solution

    KAUST Repository

    Li, Wang

    2012-10-01

    A new finite volume method for cylindrical heat conduction problems based on local analytical solution is proposed in this paper with detailed derivation. The calculation results of this new method are compared with the traditional second-order finite volume method. The newly proposed method is more accurate than conventional ones, even though the discretized expression of this proposed method is slightly more complex than the second-order central finite volume method, making it cost more calculation time on the same grids. Numerical result shows that the total CPU time of the new method is significantly less than conventional methods for achieving the same level of accuracy. © 2012 Elsevier Ltd. All rights reserved.

  10. [Research on Multi-Spectral Target Recognition System Based on the Magneto-Optical Modulation].

    Science.gov (United States)

    Yan, Xiao-yan; Qin, Jian-min; Qiao, Ji-pin

    2016-03-01

    The technology of target recognition based on characteristic multi-spectrum has many advantages, such as strong detection capability and discriminating capability of target species. But there are some problems, it requires that you obtain the background spectrum as a priori knowledge, and it requires that the change of background spectrum is small with time. Thereby its application of real-time object recognition is limited in the new environment, or the complex environment. Based on magneto-optical modulation and characteristic multi-spectrum the method is designed, and the target is identified without prior access to the background spectrum. In order to achieve the function of the target information in the one acquisition time for tested, compared to conventional methods in terms of target detection, it's adaptability is better than before on the battlefield, and it is of more practical significance. Meanwhile, the magneto-optical modulator is used to suppress the interference of stray light background, thereby improving the probability of target recognition. Since the magneto-optical modulation provides incremental iterative target spectral information, therefore, even if the unknown background spectrum or background spectrum change is large, it can significantly improve the recognition accuracy of information through an iterative target spectrum. Different test targets back shimmering light intensity and background intensity values were analyzed during experiments, results showed that three targets for linearly polarized reflectance modulation is significantly stronger than the background. And it was of great influence to visible imaging target identification when measured target used camouflage color, but the system of polarization modulation type can still recognize target well. On this basis, the target range within 0.5 km x 2 km multi-wavelength characteristics of the target species were identified. When using three characteristic wavelengths, the

  11. Rotating-Disk-Based Hybridized Electromagnetic-Triboelectric Nanogenerator for Sustainably Powering Wireless Traffic Volume Sensors.

    Science.gov (United States)

    Zhang, Binbin; Chen, Jun; Jin, Long; Deng, Weili; Zhang, Lei; Zhang, Haitao; Zhu, Minhao; Yang, Weiqing; Wang, Zhong Lin

    2016-06-28

    Wireless traffic volume detectors play a critical role for measuring the traffic-flow in a real-time for current Intelligent Traffic System. However, as a battery-operated electronic device, regularly replacing battery remains a great challenge, especially in the remote area and wide distribution. Here, we report a self-powered active wireless traffic volume sensor by using a rotating-disk-based hybridized nanogenerator of triboelectric nanogenerator and electromagnetic generator as the sustainable power source. Operated at a rotating rate of 1000 rpm, the device delivered an output power of 17.5 mW, corresponding to a volume power density of 55.7 W/m(3) (Pd = P/V, see Supporting Information for detailed calculation) at a loading resistance of 700 Ω. The hybridized nanogenerator was demonstrated to effectively harvest energy from wind generated by a moving vehicle through the tunnel. And the delivered power is capable of triggering a counter via a wireless transmitter for real-time monitoring the traffic volume in the tunnel. This study further expands the applications of triboelectric nanogenerators for high-performance ambient mechanical energy harvesting and as sustainable power sources for driving wireless traffic volume sensors.

  12. Validity and repeatability of a depth camera-based surface imaging system for thigh volume measurement.

    Science.gov (United States)

    Bullas, Alice M; Choppin, Simon; Heller, Ben; Wheat, Jon

    2016-10-01

    Complex anthropometrics such as area and volume, can identify changes in body size and shape that are not detectable with traditional anthropometrics of lengths, breadths, skinfolds and girths. However, taking these complex with manual techniques (tape measurement and water displacement) is often unsuitable. Three-dimensional (3D) surface imaging systems are quick and accurate alternatives to manual techniques but their use is restricted by cost, complexity and limited access. We have developed a novel low-cost, accessible and portable 3D surface imaging system based on consumer depth cameras. The aim of this study was to determine the validity and repeatability of the system in the measurement of thigh volume. The thigh volumes of 36 participants were measured with the depth camera system and a high precision commercially available 3D surface imaging system (3dMD). The depth camera system used within this study is highly repeatable (technical error of measurement (TEM) of <1.0% intra-calibration and ~2.0% inter-calibration) but systematically overestimates (~6%) thigh volume when compared to the 3dMD system. This suggests poor agreement yet a close relationship, which once corrected can yield a usable thigh volume measurement.

  13. Slope excavation quality assessment and excavated volume calculation in hydraulic projects based on laser scanning technology

    Directory of Open Access Journals (Sweden)

    Chao Hu

    2015-04-01

    Full Text Available Slope excavation is one of the most crucial steps in the construction of a hydraulic project. Excavation project quality assessment and excavated volume calculation are critical in construction management. The positioning of excavation projects using traditional instruments is inefficient and may cause error. To improve the efficiency and precision of calculation and assessment, three-dimensional laser scanning technology was used for slope excavation quality assessment. An efficient data acquisition, processing, and management workflow was presented in this study. Based on the quality control indices, including the average gradient, slope toe elevation, and overbreak and underbreak, cross-sectional quality assessment and holistic quality assessment methods were proposed to assess the slope excavation quality with laser-scanned data. An algorithm was also presented to calculate the excavated volume with laser-scanned data. A field application and a laboratory experiment were carried out to verify the feasibility of these methods for excavation quality assessment and excavated volume calculation. The results show that the quality assessment indices can be obtained rapidly and accurately with design parameters and scanned data, and the results of holistic quality assessment are consistent with those of cross-sectional quality assessment. In addition, the time consumption in excavation quality assessment with the laser scanning technology can be reduced by 70%–90%, as compared with the traditional method. The excavated volume calculated with the scanned data only slightly differs from measured data, demonstrating the applicability of the excavated volume calculation method presented in this study.

  14. Feasibility of CBCT-based target and normal structure delineation in prostate cancer radiotherapy: Multi-observer and image multi-modality study

    International Nuclear Information System (INIS)

    Luetgendorf-Caucig, Carola; Fotina, Irina; Stock, Markus; Poetter, Richard; Goldner, Gregor; Georg, Dietmar

    2011-01-01

    Background and purpose: In-room cone-beam CT (CBCT) imaging and adaptive treatment strategies are promising methods to decrease target volumes and to spare organs at risk. The aim of this work was to analyze the inter-observer contouring uncertainties of target volumes and organs at risks (oars) in localized prostate cancer radiotherapy using CBCT images. Furthermore, CBCT contouring was benchmarked against other image modalities (CT, MR) and the influence of subjective image quality perception on inter-observer variability was assessed. Methods and materials: Eight prostate cancer patients were selected. Seven radiation oncologists contoured target volumes and oars on CT, MRI and CBCT. Volumes, coefficient of variation (COV), conformity index (cigen), and coordinates of center-of-mass (COM) were calculated for each patient and image modality. Reliability analysis was performed for the support of the reported findings. Subjective perception of image quality was assessed via a ten-scored visual analog scale (VAS). Results: The median volume for prostate was larger on CT compared to MRI and CBCT images. The inter-observer variation for prostate was larger on CBCT (CIgen = 0.57 ± 0.09, 0.61 reliability) compared to CT (CIgen = 0.72 ± 0.07, 0.83 reliability) and MRI (CIgen = 0.66 ± 0.12, 0.87 reliability). On all image modalities values of the intra-observer reliability coefficient (0.97 for CT, 0.99 for MR and 0.94 for CBCT) indicated high reproducibility of results. For all patients the root mean square (RMS) of the inter-observer standard deviation (σ) of the COM was largest on CBCT with σ(x) = 0.4 mm, σ(y) = 1.1 mm, and σ(z) = 1.7 mm. The concordance in delineating OARs was much stronger than for target volumes, with average CIgen > 0.70 for rectum and CIgen > 0.80 for bladder. Positive correlations between CIgen and VAS score of the image quality were observed for the prostate, seminal vesicles and rectum. Conclusions: Inter-observer variability for target

  15. Development of whole-building energy design targets for commercial buildings: Phase 1, Planning: Volume 1, Final report

    Energy Technology Data Exchange (ETDEWEB)

    Crawley, D.B.; Briggs, R.S.; Jones, J.W.; Seaton, W.W.; Kaufman, J.E.; Deringer, J.J.; Kennett, E.W.

    1987-04-01

    This report describes background research for preparation of a plan for development of whole-building energy targets for new commercial buildings. The lead laboratory for this program is the Pacific Northwest Laboratory. A wide variety of expertise and resources from industry, academia, other government entities, and other DOE laboratories are used in planning, reviewing and conducting research activities. Cooperative and complementary research development, and technology transfer activities with other interested organizations are actively pursued.

  16. Converting from CT- to MRI-only-based target definition in radiotherapy of localized prostate cancer. A comparison between two modalities

    International Nuclear Information System (INIS)

    Seppaelae, Tiina; Visapaeae, Harri; Collan, Juhani; Kapanen, Mika; Kouri, Mauri; Tenhunen, Mikko; Saarilahti, Kauko; Beule, Annette

    2015-01-01

    To investigate the conversion of prostate cancer radiotherapy (RT) target definition from CT-based planning into an MRI-only-based planning procedure. Using the CT- and MRI-only-based RT planning protocols, 30 prostate cancer patients were imaged in the RT fixation position. Two physicians delineated the prostate in both CT and T2-weighted MRI images. The CT and MRI images were coregistered based on gold seeds and anatomic borders of the prostate. The uncertainty of the coregistration, as well as differences in target volumes and uncertainty of contour delineation were investigated. Conversion of margins and dose constraints from CT- to MRI-only-based treatment planning was assessed. On average, the uncertainty of image coregistration was 0.4 ± 0.5 mm (one standard deviation, SD), 0.9 ± 0.8 mm and 0.9 ± 0.9 mm in the lateral, anterior-posterior and base-apex direction, respectively. The average ratio of the prostate volume between CT and MRI was 1.20 ± 0.15 (one SD). Compared to the CT-based contours, the MRI-based contours were on average 2-7 mm smaller in the apex, 0-1 mm smaller in the rectal direction and 1-4 mm smaller elsewhere. When converting from a CT-based planning procedure to an MRI-based one, the overall planning target volumes (PTV) are prominently reduced only in the apex. The prostate margins and dose constraints can be retained by this conversion. (orig.) [de

  17. Converting from CT- to MRI-only-based target definition in radiotherapy of localized prostate cancer: A comparison between two modalities.

    Science.gov (United States)

    Seppälä, Tiina; Visapää, Harri; Collan, Juhani; Kapanen, Mika; Beule, Annette; Kouri, Mauri; Tenhunen, Mikko; Saarilahti, Kauko

    2015-11-01

    To investigate the conversion of prostate cancer radiotherapy (RT) target definition from CT-based planning into an MRI-only-based planning procedure. Using the CT- and MRI-only-based RT planning protocols, 30 prostate cancer patients were imaged in the RT fixation position. Two physicians delineated the prostate in both CT and T2-weighted MRI images. The CT and MRI images were coregistered based on gold seeds and anatomic borders of the prostate. The uncertainty of the coregistration, as well as differences in target volumes and uncertainty of contour delineation were investigated. Conversion of margins and dose constraints from CT- to MRI-only-based treatment planning was assessed. On average, the uncertainty of image coregistration was 0.4 ± 0.5 mm (one standard deviation, SD), 0.9 ± 0.8 mm and 0.9 ± 0.9 mm in the lateral, anterior-posterior and base-apex direction, respectively. The average ratio of the prostate volume between CT and MRI was 1.20 ± 0.15 (one SD). Compared to the CT-based contours, the MRI-based contours were on average 2-7 mm smaller in the apex, 0-1 mm smaller in the rectal direction and 1-4 mm smaller elsewhere. When converting from a CT-based planning procedure to an MRI-based one, the overall planning target volumes (PTV) are prominently reduced only in the apex. The prostate margins and dose constraints can be retained by this conversion.

  18. Model-based segmentation in orbital volume measurement with cone beam computed tomography and evaluation against current concepts.

    Science.gov (United States)

    Wagner, Maximilian E H; Gellrich, Nils-Claudius; Friese, Karl-Ingo; Becker, Matthias; Wolter, Franz-Erich; Lichtenstein, Juergen T; Stoetzer, Marcus; Rana, Majeed; Essig, Harald

    2016-01-01

    Objective determination of the orbital volume is important in the diagnostic process and in evaluating the efficacy of medical and/or surgical treatment of orbital diseases. Tools designed to measure orbital volume with computed tomography (CT) often cannot be used with cone beam CT (CBCT) because of inferior tissue representation, although CBCT has the benefit of greater availability and lower patient radiation exposure. Therefore, a model-based segmentation technique is presented as a new method for measuring orbital volume and compared to alternative techniques. Both eyes from thirty subjects with no known orbital pathology who had undergone CBCT as a part of routine care were evaluated (n = 60 eyes). Orbital volume was measured with manual, atlas-based, and model-based segmentation methods. Volume measurements, volume determination time, and usability were compared between the three methods. Differences in means were tested for statistical significance using two-tailed Student's t tests. Neither atlas-based (26.63 ± 3.15 mm(3)) nor model-based (26.87 ± 2.99 mm(3)) measurements were significantly different from manual volume measurements (26.65 ± 4.0 mm(3)). However, the time required to determine orbital volume was significantly longer for manual measurements (10.24 ± 1.21 min) than for atlas-based (6.96 ± 2.62 min, p model-based (5.73 ± 1.12 min, p measurements. All three orbital volume measurement methods examined can accurately measure orbital volume, although atlas-based and model-based methods seem to be more user-friendly and less time-consuming. The new model-based technique achieves fully automated segmentation results, whereas all atlas-based segmentations at least required manipulations to the anterior closing. Additionally, model-based segmentation can provide reliable orbital volume measurements when CT image quality is poor.

  19. Dose distribution assessment (comparison) in the target volume treated with VMAT given by the planning system and evaluated by TL dosimeters

    Energy Technology Data Exchange (ETDEWEB)

    Bravim, A.; Sakuraba, R.K.; Campos, L.L., E-mail: ambravim@hotmail.com [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil). Gerencia de Metrologia das Radiacoes

    2015-07-01

    Volumetric-modulated arc therapy (VMAT) is a relatively new therapy technique in which treatment is delivered using a cone beam that rotates around the patient. The radiation is delivered in a continuous gantry rotation while the cone beam is modulated by the intertwining of dynamic multileaf collimators (MLCs). Studies of VMAT plans have shown reduction in the treatment delivery time and monitor units (MU) comparable to IMRT plans improving major comfort to the patient and reducing uncertainties associated with patient movement during treatment. The treatment using VMAT minimizes the biological effects of radiation to critical structures near to the target volumes and produces excellent dose distributions. The dosimetry of ionizing radiation is essential for the radiological protection programs for quality assurance and licensing of equipment. For radiation oncology a quality assurance program is essentially to maintain the quality of patient care. As the VMAT is a new technique of radiation therapy it is important to optimize quality assurance mechanisms to ensure that tests are performed in order to preserve the patient and the equipment. This paper aims to determinate the dose distribution in the target volume (tumor to be treated) and the scattered dose distribution in the risk organs for VMAT technique comparing data given by the planning system and thermoluminescent (TL) response. (author)

  20. Quantitative assessment of inter-observer variability in target volume delineation on stereotactic radiotherapy treatment for pituitary adenoma and meningioma near optic tract

    International Nuclear Information System (INIS)

    Yamazaki, Hideya; Ogita, Mikio; Yamashita, Koichi; Kotsuma, Tadayuki; Shiomi, Hiroya; Tsubokura, Takuji; Kodani, Naohiro; Nishimura, Takuya; Aibe, Norihiro; Udono, Hiroki; Nishikata, Manabu; Baba, Yoshimi

    2011-01-01

    To assess inter-observer variability in delineating target volume and organs at risk in benign tumor adjacent to optic tract as a quality assurance exercise. We quantitatively analyzed 21 plans made by 11 clinicians in seven CyberKnife centers. The clinicians were provided with a raw data set (pituitary adenoma and meningioma) including clinical information, and were asked to delineate the lesions and create a treatment plan. Their contouring and plans (10 adenoma and 11 meningioma plans), were then compared. In addition, we estimated the influence of differences in contouring by superimposing the respective contours onto a default plan. The median planning target volume (PTV) and the ratio of the largest to the smallest contoured volume were 9.22 cm 3 (range, 7.17 - 14.3 cm 3 ) and 1.99 for pituitary adenoma, and 6.86 cm 3 (range 6.05 - 14.6 cm 3 ) and 2.41 for meningioma. PTV volume was 10.1 ± 1.74 cm 3 for group 1 with a margin of 1 -2 mm around the CTV (n = 3) and 9.28 ± 1.8 cm 3 (p = 0.51) for group 2 with no margin (n = 7) in pituitary adenoma. In meningioma, group 1 showed larger PTV volume (10.1 ± 3.26 cm 3 ) than group 2 (6.91 ± 0.7 cm 3 , p = 0.03). All submitted plan keep the irradiated dose to optic tract within the range of 50 Gy (equivalent total doses in 2 Gy fractionation). However, contours superimposed onto the dose distribution of the default plan indicated that an excessive dose 23.64 Gy (up to 268% of the default plan) in pituitary adenoma and 24.84 Gy (131% of the default plan) in meningioma to the optic nerve in the contours from different contouring. Quality assurance revealed inter-observer variability in contour delineation and their influences on planning for pituitary adenoma and meningioma near optic tract

  1. A comparison of perfusion computed tomography and contrast enhanced computed tomography on radiation target volume delineation using rabbit VX2 brain tumor model

    International Nuclear Information System (INIS)

    Sun Changjin; Luo Yunxiu; Yu Jinming; Lu Haibo; Li Chao; Zhang Dekang; Huang Jianming; Wang Jie; Lang Jinyi

    2010-01-01

    Objective: To compare the accuracy of blood volume perfusion imaging (perfusion CT)with contrast enhanced 64-slice spiral computed tomography (CECT) in the evaluation of gross tumor volume (GTV) and clinical target volume (CTV) using rabbits with VX2 brain tumor. Methods: Perfusion CT and CECT were performed in 20 rabbits with VX2 brain tumor. The GTV and CTV calculated with the maximal and minimal diameter of each tumor in the blood volume (BV) maps and CECT were measured and compared to those in pathological specimens. Results: The mean value of the maximal and minimal diameter of GTV was (8.19 ± 2.29) mm and (4.83 ± 1.31) mm in pathological specimens, (11.98 ±3.29) mm and (7.03±1.82) mm in BV maps, while (6.36±3.85) mm and (3.17±1.93) mm in CECT images, which were significantly different (pathological specimen vs. BV map, t = 7.17, P =0.000;pathological specimen vs. CECT, t = 8.37, P = 0.000, respectively). The mean value of the maximal and minimal diameter of CTV in pathologic specimens was (12.87 ± 3.74) mm and (7.71 ± 2.15) mm, which was significantly different from that of GTV and CTV in CECT (t = - 3. 18, P = 0. 005 and t = - 4.24, P =0.000; t= -11.59,P=0.000 and t= -9.39, P=0.000), while similar with that of GTV in BV maps (t = - 1.95,P = 0. 067; t = - 2. 06, P = 0. 054). For CECT, the margin from GTV to CTV was 81.83% ±40.33% for the maximal diameter and 276.73% ± 131.46% for the minimal. While for BV maps, the margin was 7.93% ± 17. 84% and 12.52% ± 27. 83%, which was significant different from that for CECT images (t=7.36, P=0. 000 and t= -8.78, P=0.000). Conclusions: Compared with CECT, the BV map from 64-slice spiral CT perfusion imaging might have higher accuracy in target volume delineation for brain tumor. (authors)

  2. Volume Averaging Theory (VAT) based modeling and closure evaluation for fin-and-tube heat exchangers

    Science.gov (United States)

    Zhou, Feng; Catton, Ivan

    2012-10-01

    A fin-and-tube heat exchanger was modeled based on Volume Averaging Theory (VAT) in such a way that the details of the original structure was replaced by their averaged counterparts, so that the VAT based governing equations can be efficiently solved for a wide range of parameters. To complete the VAT based model, proper closure is needed, which is related to a local friction factor and a heat transfer coefficient of a Representative Elementary Volume (REV). The terms in the closure expressions are complex and sometimes relating experimental data to the closure terms is difficult. In this work we use CFD to evaluate the rigorously derived closure terms over one of the selected REVs. The objective is to show how heat exchangers can be modeled as a porous media and how CFD can be used in place of a detailed, often formidable, experimental effort to obtain closure for the model.

  3. Infrared small target tracking based on sample constrained particle filtering and sparse representation

    Science.gov (United States)

    Zhang, Xiaomin; Ren, Kan; Wan, Minjie; Gu, Guohua; Chen, Qian

    2017-12-01

    Infrared search and track technology for small target plays an important role in infrared warning and guidance. In view of the tacking randomness and uncertainty caused by background clutter and noise interference, a robust tracking method for infrared small target based on sample constrained particle filtering and sparse representation is proposed in this paper. Firstly, to distinguish the normal region and interference region in target sub-blocks, we introduce a binary support vector, and combine it with the target sparse representation model, after which a particle filtering observation model based on sparse reconstruction error differences between sample targets is developed. Secondly, we utilize saliency extraction to obtain the high frequency area in infrared image, and make it as a priori knowledge of the transition probability model to limit the particle filtering sampling process. Lastly, the tracking result is brought about via target state estimation and the Bayesian posteriori probability calculation. Theoretical analyses and experimental results show that our method can enhance the state estimation ability of stochastic particles, improve the sparse representation adaptabilities for infrared small targets, and optimize the tracking accuracy for infrared small moving targets.

  4. DOA Estimation for Underwater Wideband Weak Targets Based on Coherent Signal Subspace and Compressed Sensing

    Directory of Open Access Journals (Sweden)

    Jun Li

    2018-03-01

    Full Text Available Direction of arrival (DOA estimation is the basis for underwater target localization and tracking using towed line array sonar devices. A method of DOA estimation for underwater wideband weak targets based on coherent signal subspace (CSS processing and compressed sensing (CS theory is proposed. Under the CSS processing framework, wideband frequency focusing is accompanied by a two-sided correlation transformation, allowing the DOA of underwater wideband targets to be estimated based on the spatial sparsity of the targets and the compressed sensing reconstruction algorithm. Through analysis and processing of simulation data and marine trial data, it is shown that this method can accomplish the DOA estimation of underwater wideband weak targets. Results also show that this method can considerably improve the spatial spectrum of weak target signals, enhancing the ability to detect them. It can solve the problems of low directional resolution and unreliable weak-target detection in traditional beamforming technology. Compared with the conventional minimum variance distortionless response beamformers (MVDR, this method has many advantages, such as higher directional resolution, wider detection range, fewer required snapshots and more accurate detection for weak targets.

  5. A Side Scan Sonar Image Target Detection Algorithm Based on a Neutrosophic Set and Diffusion Maps

    Directory of Open Access Journals (Sweden)

    Xiao Wang

    2018-02-01

    Full Text Available To accurately achieve side scan sonar (SSS image target detection, a novel target detection algorithm based on a neutrosophic set (NS and diffusion maps (DMs is proposed in this paper. Firstly, the neutrosophic subset images were obtained by transforming the input SSS image into the NS domain. Secondly, the shadowed areas of the SSS image were detected using the single gray value threshold method before the diffusion map was calculated. Lastly, based on the diffusion map, the target areas were detected using the improved target scoring equation defined by the diffusion distance and texture feature. The experiments using SSS images of single clear and unclear targets, with or without shadowed areas, showed that the algorithm accurately detects targets. Experiments using SSS images of multiple targets, with or without shadowed areas, showed that no false or missing detections occurred. The target areas were also accurately detected in SSS images with complex features such as sand wave terrain. The accuracy and effectiveness of the proposed algorithm were assessed.

  6. Information-management data base for fusion-target fabrication processes

    International Nuclear Information System (INIS)

    Reynolds, J.

    1982-01-01

    A computer-based data-management system has been developed to handle data associated with target-fabrication processes including glass microballoon characterization, gas filling, materials coating, and storage locations. The system provides automatic data storage and computation, flexible data-entry procedures, fast access, automated report generation, and secure data transfer. It resides on a CDC CYBER 175 computer and is compatible with the CDC data-base-language Query Update, but is based on custom FORTRAN software interacting directly with the CYBER's file-management system. The described data base maintains detailed, accurate, and readily available records of fusion targets information

  7. Mung bean nuclease treatment increases capture specificity of microdroplet-PCR based targeted DNA enrichment.

    Directory of Open Access Journals (Sweden)

    Zhenming Yu

    Full Text Available Targeted DNA enrichment coupled with next generation sequencing has been increasingly used for interrogation of select sub-genomic regions at high depth of coverage in a cost effective manner. Specificity measured by on-target efficiency is a key performance metric for target enrichment. Non-specific capture leads to off-target reads, resulting in waste of sequencing throughput on irrelevant regions. Microdroplet-PCR allows simultaneous amplification of up to thousands of regions in the genome and is among the most commonly used strategies for target enrichment. Here we show that carryover of single-stranded template genomic DNA from microdroplet-PCR constitutes a major contributing factor for off-target reads in the resultant libraries. Moreover, treatment of microdroplet-PCR enrichment products with a nuclease specific to single-stranded DNA alleviates off-target load and improves enrichment specificity. We propose that nuclease treatment of enrichment products should be incorporated in the workflow of targeted sequencing using microdroplet-PCR for target capture. These findings may have a broad impact on other PCR based applications for which removal of template DNA is beneficial.

  8. Toward Semi-automated Assessment of Target Volume Delineation in Radiotherapy Trials: The SCOPE 1 Pretrial Test Case

    International Nuclear Information System (INIS)

    Gwynne, Sarah; Spezi, Emiliano; Wills, Lucy; Nixon, Lisette; Hurt, Chris; Joseph, George; Evans, Mererid; Griffiths, Gareth; Crosby, Tom; Staffurth, John

    2012-01-01

    Purpose: To evaluate different conformity indices (CIs) for use in the analysis of outlining consistency within the pretrial quality assurance (Radiotherapy Trials Quality Assurance [RTTQA]) program of a multicenter chemoradiation trial of esophageal cancer and to make recommendations for their use in future trials. Methods and Materials: The National Cancer Research Institute SCOPE 1 trial is an ongoing Cancer Research UK-funded phase II/III randomized controlled trial of chemoradiation with capecitabine and cisplatin with or without cetuximab for esophageal cancer. The pretrial RTTQA program included a detailed radiotherapy protocol, an educational package, and a single mid-esophageal tumor test case that were sent to each investigator to outline. Investigator gross tumor volumes (GTVs) were received from 50 investigators in 34 UK centers, and CERR (Computational Environment for Radiotherapy Research) was used to perform an assessment of each investigator GTV against a predefined gold-standard GTV using different CIs. A new metric, the local conformity index (l-CI), that can localize areas of maximal discordance was developed. Results: The median Jaccard conformity index (JCI) was 0.69 (interquartile range, 0.62-0.70), with 14 of 50 investigators (28%) achieving a JCI of 0.7 or greater. The median geographical miss index was 0.09 (interquartile range, 0.06-0.16), and the mean discordance index was 0.27 (95% confidence interval, 0.25-0.30). The l-CI was highest in the middle section of the volume, where the tumor was bulky and more easily definable, and identified 4 slices where fewer than 20% of investigators achieved an l-CI of 0.7 or greater. Conclusions: The available CIs analyze different aspects of a gold standard–observer variation, with JCI being the most useful as a single metric. Additional information is provided by the l-CI and can focus the efforts of the RTTQA team in these areas, possibly leading to semi-automated outlining assessment.

  9. Influence networks based on coexpression improve drug target discovery for the development of novel cancer therapeutics

    Science.gov (United States)

    2014-01-01

    Background The demand for novel molecularly targeted drugs will continue to rise as we move forward toward the goal of personalizing cancer treatment to the molecular signature of individual tumors. However, the identification of targets and combinations of targets that can be safely and effectively modulated is one of the greatest challenges facing the drug discovery process. A promising approach is to use biological networks to prioritize targets based on their relative positions to one another, a property that affects their ability to maintain network integrity and propagate information-flow. Here, we introduce influence networks and demonstrate how they can be used to generate influence scores as a network-based metric to rank genes as potential drug targets. Results We use this approach to prioritize genes as drug target candidates in a set of ER + breast tumor samples collected during the course of neoadjuvant treatment with the aromatase inhibitor letrozole. We show that influential genes, those with high influence scores, tend to be essential and include a higher proportion of essential genes than those prioritized based on their position (i.e. hubs or bottlenecks) within the same network. Additionally, we show that influential genes represent novel biologically relevant drug targets for the treatment of ER + breast cancers. Moreover, we demonstrate that gene influence differs between untreated tumors and residual tumors that have adapted to drug treatment. In this way, influence scores capture the context-dependent functions of genes and present the opportunity to design combination treatment strategies that take advantage of the tumor adaptation process. Conclusions Influence networks efficiently find essential genes as promising drug targets and combinations of targets to inform the development of molecularly targeted drugs and their use. PMID:24495353

  10. SHTEREOM I SIMPLE WINDOWS® BASED SOFTWARE FOR STEREOLOGY. VOLUME AND NUMBER ESTIMATIONS

    Directory of Open Access Journals (Sweden)

    Emin Oğuzhan Oğuz

    2011-05-01

    Full Text Available Stereology has been earlier defined by Wiebel (1970 to be: "a body of mathematical methods relating to three dimensional parameters defining the structure from two dimensional measurements obtainable on sections of the structure." SHTEREOM I is a simple windows-based software for stereological estimation. In this first part, we describe the implementation of the number and volume estimation tools for unbiased design-based stereology. This software is produced in Visual Basic and can be used on personal computers operated by Microsoft Windows® operating systems that are connected to a conventional camera attached to a microscope and a microcator or a simple dial gauge. Microsoft NET Framework version 1.1 also needs to be downloaded for full use. The features of the SHTEREOM I software are illustrated through examples of stereological estimations in terms of volume and particle numbers for different magnifications (4X–100X. Point-counting grids are available for area estimations and for use with the most efficient volume estimation tool, the Cavalieri technique and are applied to Lizard testicle volume. An unbiased counting frame system is available for number estimations of the objects under investigation, and an on-screen manual stepping module for number estimations through the optical fractionator method is also available for the measurement of increments along the X and Y axes of the microscope stage for the estimation of rat brain hippocampal pyramidal neurons.

  11. Curvature computation in volume-of-fluid method based on point-cloud sampling

    Science.gov (United States)

    Kassar, Bruno B. M.; Carneiro, João N. E.; Nieckele, Angela O.

    2018-01-01

    This work proposes a novel approach to compute interface curvature in multiphase flow simulation based on Volume of Fluid (VOF) method. It is well documented in the literature that curvature and normal vector computation in VOF may lack accuracy mainly due to abrupt changes in the volume fraction field across the interfaces. This may cause deterioration on the interface tension forces estimates, often resulting in inaccurate results for interface tension dominated flows. Many techniques have been presented over the last years in order to enhance accuracy in normal vectors and curvature estimates including height functions, parabolic fitting of the volume fraction, reconstructing distance functions, coupling Level Set method with VOF, convolving the volume fraction field with smoothing kernels among others. We propose a novel technique based on a representation of the interface by a cloud of points. The curvatures and the interface normal vectors are computed geometrically at each point of the cloud and projected onto the Eulerian grid in a Front-Tracking manner. Results are compared to benchmark data and significant reduction on spurious currents as well as improvement in the pressure jump are observed. The method was developed in the open source suite OpenFOAM® extending its standard VOF implementation, the interFoam solver.

  12. Comparison of provider and plan-based targeting strategies for disease management.

    Science.gov (United States)

    Annis, Ann M; Holtrop, Jodi Summers; Tao, Min; Chang, Hsiu-Ching; Luo, Zhehui

    2015-05-01

    We aimed to describe and contrast the targeting methods and engagement outcomes for health plan-delivered disease management with those of a provider-delivered care management program. Health plan epidemiologists partnered with university health services researchers to conduct a quasi-experimental, mixed-methods study of a 2-year pilot. We used semi-structured interviews to assess the characteristics of program-targeting strategies, and calculated target and engagement rates from clinical encounter data. Five physician organizations (POs) with 51 participating practices implemented care management. Health plan member lists were sent monthly to the practices to accept patients, and then the practices sent back data reports regarding targeting and engagement in care management. Among patients accepted by the POs, we compared those who were targeted and engaged by POs with those who met health plan targeting criteria. The health plan's targeting process combined claims algorithms and employer group preferences to identify candidates for disease management; on the other hand, several different factors influenced PO practices' targeting approaches, including clinical and personal knowledge of the patients, health assessment information, and availability of disease-relevant programs. Practices targeted a higher percentage of patients for care management than the health plan (38% vs 16%), where only 7% of these patients met the targeting criteria of both. Practices engaged a higher percentage of their targeted patients than the health plan (50% vs 13%). The health plan's claims-driven targeting approach and the clinically based strategies of practices both provide advantages; an optimal model may be to combine the strengths of each approach to maximize benefits in care management.

  13. Prediction of drug-target interactions for drug repositioning only based on genomic expression similarity.

    Directory of Open Access Journals (Sweden)

    Kejian Wang

    Full Text Available Small drug molecules usually bind to multiple protein targets or even unintended off-targets. Such drug promiscuity has often led to unwanted or unexplained drug reactions, resulting in side effects or drug repositioning opportunities. So it is always an important issue in pharmacology to identify potential drug-target interactions (DTI. However, DTI discovery by experiment remains a challenging task, due to high expense of time and resources. Many computational methods are therefore developed to predict DTI with high throughput biological and clinical data. Here, we initiatively demonstrate that the on-target and off-target effects could be characterized by drug-induced in vitro genomic expression changes, e.g. the data in Connectivity Map (CMap. Thus, unknown ligands of a certain target can be found from the compounds showing high gene-expression similarity to the known ligands. Then to clarify the detailed practice of CMap based DTI prediction, we objectively evaluate how well each target is characterized by CMap. The results suggest that (1 some targets are better characterized than others, so the prediction models specific to these well characterized targets would be more accurate and reliable; (2 in some cases, a family of ligands for the same target tend to interact with common off-targets, which may help increase the efficiency of DTI discovery and explain the mechanisms of complicated drug actions. In the present study, CMap expression similarity is proposed as a novel indicator of drug-target interactions. The detailed strategies of improving data quality by decreasing the batch effect and building prediction models are also effectively established. We believe the success in CMap can be further translated into other public and commercial data of genomic expression, thus increasing research productivity towards valid drug repositioning and minimal side effects.

  14. Field lens multiplexing in holographic 3D displays by using Bragg diffraction based volume gratings

    Science.gov (United States)

    Fütterer, G.

    2016-11-01

    Applications, which can profit from holographic 3D displays, are the visualization of 3D data, computer-integrated manufacturing, 3D teleconferencing and mobile infotainment. However, one problem of holographic 3D displays, which are e.g. based on space bandwidth limited reconstruction of wave segments, is to realize a small form factor. Another problem is to provide a reasonable large volume for the user placement, which means to provide an acceptable freedom of movement. Both problems should be solved without decreasing the image quality of virtual and real object points, which are generated within the 3D display volume. A diffractive optical design using thick hologram gratings, which can be referred to as Bragg diffraction based volume gratings, can provide a small form factor and high definition natural viewing experience of 3D objects. A large collimated wave can be provided by an anamorphic backlight unit. The complex valued spatial light modulator add local curvatures to the wave field he is illuminated with. The modulated wave field is focused onto to the user plane by using a volume grating based field lens. Active type liquid crystal gratings provide 1D fine tracking of approximately +/- 8° deg. Diffractive multiplex has to be implemented for each color and for a set of focus functions providing coarse tracking. Boundary conditions of the diffractive multiplexing are explained. This is done in regards to the display layout and by using the coupled wave theory (CWT). Aspects of diffractive cross talk and its suppression will be discussed including longitudinal apodized volume gratings.

  15. Improved OAM-Based Radar Targets Detection Using Uniform Concentric Circular Arrays

    Directory of Open Access Journals (Sweden)

    Mingtuan Lin

    2016-01-01

    Full Text Available Without any relative moves or beam scanning, the novel Orbital-Angular-Momentum- (OAM- based radar targets detection technique using uniform concentric circular arrays (UCCAs shows the azimuthal estimation ability, which provides new perspective for radar system design. However, the main estimation method, that is, Fast Fourier Transform (FFT, under this scheme suffers from low resolution. As a solution, this paper rebuilds the OAM-based radar targets detection model and introduces the multiple signal classification (MUSIC algorithm to improve the resolution for detecting targets within the main lobes. The spatial smoothing technique is proposed to tackle the coherent problem brought by the proposed model. Analytical study and simulation demonstrate the superresolution estimation capacity the MUSIC algorithm can achieve for detecting targets within the main lobes. The performance of the MUSIC algorithm to detect targets not illuminated by the main lobes is further evaluated. Despite the fact that MUSIC algorithm loses the resolution advantage under this case, its estimation is more robust than that of the FFT method. Overall, the proposed MUSIC algorithm for the OAM-based radar system demonstrates the superresolution ability for detecting targets within the main lobes and good robustness for targets out of the main lobes.

  16. SU-E-T-762: Toward Volume-Based Independent Dose Verification as Secondary Check

    International Nuclear Information System (INIS)

    Tachibana, H; Tachibana, R

    2015-01-01

    Purpose: Lung SBRT plan has been shifted to volume prescription technique. However, point dose agreement is still verified using independent dose verification at the secondary check. The volume dose verification is more affected by inhomogeneous correction rather than point dose verification currently used as the check. A feasibility study for volume dose verification was conducted in lung SBRT plan. Methods: Six SBRT plans were collected in our institute. Two dose distributions with / without inhomogeneous correction were generated using Adaptive Convolve (AC) in Pinnacle3. Simple MU Analysis (SMU, Triangle Product, Ishikawa, JP) was used as the independent dose verification software program, in which a modified Clarkson-based algorithm was implemented and radiological path length was computed using CT images independently to the treatment planning system. The agreement in point dose and mean dose between the AC with / without the correction and the SMU were assessed. Results: In the point dose evaluation for the center of the GTV, the difference shows the systematic shift (4.5% ± 1.9 %) in comparison of the AC with the inhomogeneous correction, on the other hands, there was good agreement of 0.2 ± 0.9% between the SMU and the AC without the correction. In the volume evaluation, there were significant differences in mean dose for not only PTV (14.2 ± 5.1 %) but also GTV (8.0 ± 5.1 %) compared to the AC with the correction. Without the correction, the SMU showed good agreement for GTV (1.5 ± 0.9%) as well as PTV (0.9% ± 1.0%). Conclusion: The volume evaluation for secondary check may be possible in homogenous region. However, the volume including the inhomogeneous media would make larger discrepancy. Dose calculation algorithm for independent verification needs to be modified to take into account the inhomogeneous correction

  17. Adaptive detection method of infrared small target based on target-background separation via robust principal component analysis

    Science.gov (United States)

    Wang, Chuanyun; Qin, Shiyin

    2015-03-01

    Motivated by the robust principal component analysis, infrared small target image is regarded as low-rank background matrix corrupted by sparse target and noise matrices, thus a new target-background separation model is designed, subsequently, an adaptive detection method of infrared small target is presented. Firstly, multi-scale transform and patch transform are used to generate an image patch set for infrared small target detection; secondly, target-background separation of each patch is achieved by recovering the low-rank and sparse matrices using adaptive weighting parameter; thirdly, the image reconstruction and fusion are carried out to obtain the entire separated background and target images; finally, the infrared small target detection is realized by threshold segmentation of template matching similarity measurement. In order to validate the performance of the proposed method, three experiments: target-background separation, background clutter suppression and infrared small target detection, are performed over different clutter background with real infrared small targets in single-frame or sequence images. A series of experiment results demonstrate that the proposed method can not only suppress background clutter effectively even if with strong noise interference but also detect targets accurately with low false alarm rate.

  18. Phase-contrast MRI volume flow – a comparison of breath held and navigator based acquisitions

    International Nuclear Information System (INIS)

    Andersson, Charlotta; Kihlberg, Johan; Ebbers, Tino; Lindström, Lena; Carlhäll, Carl-Johan; Engvall, Jan E.

    2016-01-01

    Magnetic Resonance Imaging (MRI) 2D phase-contrast flow measurement has been regarded as the gold standard in blood flow measurements and can be performed with free breathing or breath held techniques. We hypothesized that the accuracy of flow measurements obtained with segmented phase-contrast during breath holding, and in particular higher number of k-space segments, would be non-inferior compared to navigator phase-contrast. Volumes obtained from anatomic segmentation of cine MRI and Doppler echocardiography were used for additional reference. Forty patients, five women and 35 men, mean age 65 years (range 53–80), were randomly selected and consented to the study. All underwent EKG-gated cardiac MRI including breath hold cine, navigator based free-breathing phase-contrast MRI and breath hold phase-contrast MRI using k-space segmentation factors 3 and 5, as well as transthoracic echocardiography within 2 days. In navigator based free-breathing phase-contrast flow, mean stroke volume and cardiac output were 79.7 ± 17.1 ml and 5071 ± 1192 ml/min, respectively. The duration of the acquisition was 50 ± 6 s. With k-space segmentation factor 3, the corresponding values were 77.7 ml ± 17.5 ml and 4979 ± 1211 ml/min (p = 0.15 vs navigator). The duration of the breath hold was 17 ± 2 s. K-space segmentation factor 5 gave mean stroke volume 77.9 ± 16.4 ml, cardiac output 5142 ± 1197 ml/min (p = 0.33 vs navigator), and breath hold time 11 ± 1 s. Anatomical segmentation of cine gave mean stroke volume and cardiac output 91.2 ± 20.8 ml and 5963 ± 1452 ml/min, respectively. Echocardiography was reliable in 20 of the 40 patients. The mean diameter of the left ventricular outflow tract was 20.7 ± 1.5 mm, stroke volume 78.3 ml ± 15.2 ml and cardiac output 5164 ± 1249 ml/min. In forty consecutive patients with coronary heart disease, breath holding and segmented k-space sampling techniques for phase-contrast flow produced stroke volumes and cardiac outputs similar

  19. Feature Extraction of Underwater Target Signal Using Mel Frequency Cepstrum Coefficients Based on Acoustic Vector Sensor

    Directory of Open Access Journals (Sweden)

    Lanyue Zhang

    2016-01-01

    Full Text Available Feature extraction method using Mel frequency cepstrum coefficients (MFCC based on acoustic vector sensor is researched in the paper. Signals of pressure are simulated as well as particle velocity of underwater target, and the features of underwater target using MFCC are extracted to verify the feasibility of the method. The experiment of feature extraction of two kinds of underwater targets is carried out, and these underwater targets are classified and recognized by Backpropagation (BP neural network using fusion of multi-information. Results of the research show that MFCC, first-order differential MFCC, and second-order differential MFCC features could be used as effective features to recognize those underwater targets and the recognition rate, which using the particle velocity signal is higher than that using the pressure signal, could be improved by using fusion features.

  20. Multi-target Particle Filter Tracking Algorithm Based on Wireless Sensor Networks

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    Liu Hong-Xia

    2014-05-01

    Full Text Available In order to improve the multi-target tracking efficiency for wireless sensor networks and solve the problem of data transmission, analyzed existing particle filter tracking algorithm, ensure that one of the core technology for wireless sensor network performance. In this paper, from the basic theory of target tracking, in-depth analysis on the basis of the principle of particle filter, based on dynamic clustering, proposed the multi-target Kalman particle filter (MEPF algorithm, through the expansion of Calman filter (EKF to generate the proposal distribution, a reduction in the required number of particles to improve the particle filter accuracy at the same time, reduce the computational complexity of target tracking algorithm, thus reducing the energy consumption. Application results show that the MEPF in the proposed algorithm can achieve better tracking of target tracking and forecasting, in a small number of particles still has good tracking accuracy.

  1. Bag-of-visual-words based feature extraction for SAR target classification

    Science.gov (United States)

    Amrani, Moussa; Chaib, Souleyman; Omara, Ibrahim; Jiang, Feng

    2017-07-01

    Feature extraction plays a key role in the classification performance of synthetic aperture radar automatic target recognition (SAR-ATR). It is very crucial to choose appropriate features to train a classifier, which is prerequisite. Inspired by the great success of Bag-of-Visual-Words (BoVW), we address the problem of feature extraction by proposing a novel feature extraction method for SAR target classification. First, Gabor based features are adopted to extract features from the training SAR images. Second, a discriminative codebook is generated using K-means clustering algorithm. Third, after feature encoding by computing the closest Euclidian distance, the targets are represented by new robust bag of features. Finally, for target classification, support vector machine (SVM) is used as a baseline classifier. Experiments on Moving and Stationary Target Acquisition and Recognition (MSTAR) public release dataset are conducted, and the classification accuracy and time complexity results demonstrate that the proposed method outperforms the state-of-the-art methods.

  2. Maximum Likelihood-Based Methods for Target Velocity Estimation with Distributed MIMO Radar

    Directory of Open Access Journals (Sweden)

    Zhenxin Cao

    2018-02-01

    Full Text Available The estimation problem for target velocity is addressed in this in the scenario with a distributed multi-input multi-out (MIMO radar system. A maximum likelihood (ML-based estimation method is derived with the knowledge of target position. Then, in the scenario without the knowledge of target position, an iterative method is proposed to estimate the target velocity by updating the position information iteratively. Moreover, the Carmér-Rao Lower Bounds (CRLBs for both scenarios are derived, and the performance degradation of velocity estimation without the position information is also expressed. Simulation results show that the proposed estimation methods can approach the CRLBs, and the velocity estimation performance can be further improved by increasing either the number of radar antennas or the information accuracy of the target position. Furthermore, compared with the existing methods, a better estimation performance can be achieved.

  3. Research on regional intrusion prevention and control system based on target tracking

    Science.gov (United States)

    Liu, Yanfei; Wang, Jieling; Jiang, Ke; He, Yanhui; Wu, Zhilin

    2017-08-01

    In view of the fact that China’s border is very long and the border prevention and control measures are single, we designed a regional intrusion prevention and control system which based on target-tracking. The system consists of four parts: solar panel, radar, electro-optical equipment, unmanned aerial vehicle and intelligent tracking platform. The solar panel provides independent power for the entire system. The radar detects the target in real time and realizes the high precision positioning of suspicious targets, then through the linkage of electro-optical equipment, it can achieve full-time automatic precise tracking of targets. When the target appears within the range of detection, the drone will be launched to continue the tracking. The system is mainly to realize the full time, full coverage, whole process integration and active realtime control of the border area.

  4. Uncertainty modelling and analysis of volume calculations based on a regular grid digital elevation model (DEM)

    Science.gov (United States)

    Li, Chang; Wang, Qing; Shi, Wenzhong; Zhao, Sisi

    2018-05-01

    The accuracy of earthwork calculations that compute terrain volume is critical to digital terrain analysis (DTA). The uncertainties in volume calculations (VCs) based on a DEM are primarily related to three factors: 1) model error (ME), which is caused by an adopted algorithm for a VC model, 2) discrete error (DE), which is usually caused by DEM resolution and terrain complexity, and 3) propagation error (PE), which is caused by the variables' error. Based on these factors, the uncertainty modelling and analysis of VCs based on a regular grid DEM are investigated in this paper. Especially, how to quantify the uncertainty of VCs is proposed by a confidence interval based on truncation error (TE). In the experiments, the trapezoidal double rule (TDR) and Simpson's double rule (SDR) were used to calculate volume, where the TE is the major ME, and six simulated regular grid DEMs with different terrain complexity and resolution (i.e. DE) were generated by a Gauss synthetic surface to easily obtain the theoretical true value and eliminate the interference of data errors. For PE, Monte-Carlo simulation techniques and spatial autocorrelation were used to represent DEM uncertainty. This study can enrich uncertainty modelling and analysis-related theories of geographic information science.

  5. Automatic segmentation of the clinical target volume and organs at risk in the planning CT for rectal cancer using deep dilated convolutional neural networks.

    Science.gov (United States)

    Men, Kuo; Dai, Jianrong; Li, Yexiong

    2017-12-01

    Delineation of the clinical target volume (CTV) and organs at risk (OARs) is very important for radiotherapy but is time-consuming and prone to inter-observer variation. Here, we proposed a novel deep dilated convolutional neural network (DDCNN)-based method for fast and consistent auto-segmentation of these structures. Our DDCNN method was an end-to-end architecture enabling fast training and testing. Specifically, it employed a novel multiple-scale convolutional architecture to extract multiple-scale context features in the early layers, which contain the original information on fine texture and boundaries and which are very useful for accurate auto-segmentation. In addition, it enlarged the receptive fields of dilated convolutions at the end of networks to capture complementary context features. Then, it replaced the fully connected layers with fully convolutional layers to achieve pixel-wise segmentation. We used data from 278 patients with rectal cancer for evaluation. The CTV and OARs were delineated and validated by senior radiation oncologists in the planning computed tomography (CT) images. A total of 218 patients chosen randomly were used for training, and the remaining 60 for validation. The Dice similarity coefficient (DSC) was used to measure segmentation accuracy. Performance was evaluated on segmentation of the CTV and OARs. In addition, the performance of DDCNN was compared with that of U-Net. The proposed DDCNN method outperformed the U-Net for all segmentations, and the average DSC value of DDCNN was 3.8% higher than that of U-Net. Mean DSC values of DDCNN were 87.7% for the CTV, 93.4% for the bladder, 92.1% for the left femoral head, 92.3% for the right femoral head, 65.3% for the intestine, and 61.8% for the colon. The test time was 45 s per patient for segmentation of all the CTV, bladder, left and right femoral heads, colon, and intestine. We also assessed our approaches and results with those in the literature: our system showed superior