Correction of respiratory motion for IMRT using aperture adaptive technique and visual guidance: A feasibility study

NASA Astrophysics Data System (ADS)

Chen, Ho-Hsing; Wu, Jay; Chuang, Keh-Shih; Kuo, Hsiang-Chi

2007-07-01

Intensity-modulated radiation therapy (IMRT) utilizes nonuniform beam profile to deliver precise radiation doses to a tumor while minimizing radiation exposure to surrounding normal tissues. However, the problem of intrafraction organ motion distorts the dose distribution and leads to significant dosimetric errors. In this research, we applied an aperture adaptive technique with a visual guiding system to toggle the problem of respiratory motion. A homemade computer program showing a cyclic moving pattern was projected onto the ceiling to visually help patients adjust their respiratory patterns. Once the respiratory motion becomes regular, the leaf sequence can be synchronized with the target motion. An oscillator was employed to simulate the patient's breathing pattern. Two simple fields and one IMRT field were measured to verify the accuracy. Preliminary results showed that after appropriate training, the amplitude and duration of volunteer's breathing can be well controlled by the visual guiding system. The sharp dose gradient at the edge of the radiation fields was successfully restored. The maximum dosimetric error in the IMRT field was significantly decreased from 63% to 3%. We conclude that the aperture adaptive technique with the visual guiding system can be an inexpensive and feasible alternative without compromising delivery efficiency in clinical practice.

TU-E-TOUR-I-00: Exhibit Hall Guided Tours-Dosimters for QC in Diagnostic Imaging (Tuesday)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Tour Leader: Xia Jiang, Ohio State University, Columbus, OH Tour Guides: Xia Jiang, Ohio State University, Columbus, OH Kevin Little, The University of Chicago, Chicago, IL Christina Sammet, Lurie Children’s Hospital of Chicago, Chicago, IL Participating Vendors: IBA PTW - New York Radcal Corporation RTI Electronics, Inc. Exhibit Hall Guided Tours is a new program launching this year at the Annual Meeting. The Guided Tours are designed to enhance the interaction between meeting attendees and exhibitors. This year’s Imaging Guided Tours are organized around the theme of dosimeters for quality control in diagnostic imaging. Tours will begin with an introductionmore » and background given by Dr. Xia Jiang, the Tour Leader. The introduction will cover the types and properties of different radiation dosimeters used for quality assurance in clinical radiology. Attendees will then break into smaller groups, each lead by an AAPM-member Tour Guide. The tour groups will visit the exhibit booths of vendors who provide appropriate dosimeters, and a vendor representative will give a presentation to the group about their particular product(s). The vendor representatives as well as the Tour Guides will be available to answer questions. Outline: Types and properties of radiation detectors and dosimeters Ionization chamber dosimeters Solid state dosimeters Dosimeter calibration: Primary and secondary standards dosimetry laboratories Instruments for measuring tube voltage and exposure time Vendor presentations will likely cover features and innovations of different dosimeter systems, as well as their practical use. Learning Objectives: Understand the types and properties of different instrumentations used for quality control in diagnostic imaging. Understand the process of dosimeter calibration. Gain familiarity with the latest commercial dosimeter systems from different vendors.« less

WE-C-TOUR-I-00: Exhibit Hall Guided Tours-Dosimters for QC in Diagnostic Imaging (Wednesday)

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Tour Leader: Xia Jiang, Ohio State University, Columbus, OH Tour Guides: Xia Jiang, Ohio State University, Columbus, OH Kevin Little, The University of Chicago, Chicago, IL Adrien Sanchez, University of Chicago, Chicago, IL Participating Vendors: IBA PTW - New York Radcal Corporation RTI Electronics, Inc. Exhibit Hall Guided Tours is a new program launching this year at the Annual Meeting. The Guided Tours are designed to enhance the interaction between meeting attendees and exhibitors. This year’s Imaging Guided Tours are organized around the theme of dosimeters for quality control in diagnostic imaging. Tours will begin with an introduction and backgroundmore » given by Dr. Xia Jiang, the Tour Leader. The introduction will cover the types and properties of different radiation dosimeters used for quality assurance in clinical radiology. Attendees will then break into smaller groups, each lead by an AAPM-member Tour Guide. The tour groups will visit the exhibit booths of vendors who provide appropriate dosimeters, and a vendor representative will give a presentation to the group about their particular product(s). The vendor representatives as well as the Tour Guides will be available to answer questions. Outline: Types and properties of radiation detectors and dosimeters Ionization chamber dosimeters Solid state dosimeters Dosimeter calibration: Primary and secondary standards dosimetry laboratories Instruments for measuring tube voltage and exposure time Vendor presentations will likely cover features and innovations of different dosimeter systems, as well as their practical use. Learning Objectives: Understand the types and properties of different instrumentations used for quality control in diagnostic imaging. Understand the process of dosimeter calibration. Gain familiarity with the latest commercial dosimeter systems from different vendors.« less

New era of radiotherapy: an update in radiation-induced lung disease

PubMed Central

Benveniste, M. F. K.; Welsh, J.; Godoy, M. C. B.; Betancourt, S. L.; Mawlawi, O. R; Munden, R. F.

2014-01-01

Over the last few decades, advances in radiotherapy (RT) technology have improved delivery of radiation therapy dramatically. Advances in treatment planning with the development of image-guided radiotherapy and in techniques such as proton therapy, allows the radiation therapist to direct high doses of radiation to the tumour. These advancements result in improved local regional control while reducing potentially damaging dosage to surrounding normal tissues. It is important for radiologists to be aware of the radiological findings from these advances in order to differentiate expected radiation-induced lung injury (RILD) from recurrence, infection, and other lung diseases. In order to understand these changes and correlate them with imaging, the radiologist should have access to the radiation therapy treatment plans. PMID:23473474

Lightweight bilayer barium sulfate-bismuth oxide composite thyroid collars for superior radiation protection in fluoroscopy-guided interventions: a prospective randomized controlled trial.

PubMed

Uthoff, Heiko; Benenati, Matthew J; Katzen, Barry T; Peña, Constantino; Gandhi, Ripal; Staub, Daniel; Schernthaner, Melanie

2014-02-01

To test whether newer bilayer barium sulfate-bismuth oxide composite (XPF) thyroid collars (TCs) provide superior radiation protection and comfort during fluoroscopy-guided interventions compared with standard 0.5-mm lead-equivalent TCs. Institutional review board approval and written informed consent were obtained for this HIPAA-compliant study, and 144 fluoroscopy-guided vascular interventions were included at one center between October 2011 and July 2012, with up to two operators randomly assigned to wear XPF (n = 135) or standard 0.5-mm lead-equivalent (n = 121) TCs. Radiation doses were measured by using dosimeters placed outside and underneath the TCs. Wearing comfort was assessed at the end of each procedure on a visual analog scale (0-100, with 100 indicating optimal comfort). Adjusted differences in comfort and radiation dose reductions were calculated by using a mixed logistic regression model and the common method of inverse variance weighting, respectively. Patient (height, weight, and body mass index) and procedure (type and duration of intervention, operator, fluoroscopy time, dose-area product, and air kerma) data did not differ between the XPF and standard groups. Comfort was assessed in all 256 measurements. On average, the XPF TCs were 47.6% lighter than the standard TCs (mean weight ± standard deviation, 133 g ± 14 vs 254 g ± 44; P < .001) and had a significantly higher likelihood of a high level of comfort (visual analog scale >90; odds ratio, 7.6; 95% confidence interval: 3.0, 19.2; P < .001). Radiation dose reduction provided by the TCs was analyzed in 117 data sets (60 in the XPF group, 57 in the standard group). The mean radiation dose reductions (ie, radiation protection) provided by XPF and standard TCs were 90.7% and 72.4%, with an adjusted mean difference of 17.9% (95% confidence interval: 7.7%, 28.1%; P < .001) favoring XPF. XPF TCs are a lightweight alternative to standard 0.5-mm lead-equivalent TCs and provide superior radiation protection during fluoroscopy-guided interventions. © RSNA, 2013.

[Task sharing with radiotherapy technicians in image-guided radiotherapy].

PubMed

Diaz, O; Lorchel, F; Revault, C; Mornex, F

2013-10-01

The development of accelerators with on-board imaging systems now allows better target volumes reset at the time of irradiation (image-guided radiotherapy [IGRT]). However, these technological advances in the control of repositioning led to a multiplication of tasks for each actor in radiotherapy and increase the time available for the treatment, whether for radiotherapy technicians or radiation oncologists. As there is currently no explicit regulatory framework governing the use of IGRT, some institutional experiments show that a transfer is possible between radiation oncologists and radiotherapy technicians for on-line verification of image positioning. Initial training for every technical and drafting procedures within institutions will improve audit quality by reducing interindividual variability. Copyright © 2013. Published by Elsevier SAS.

Near-field interference for the unidirectional excitation of electromagnetic guided modes.

PubMed

Rodríguez-Fortuño, Francisco J; Marino, Giuseppe; Ginzburg, Pavel; O'Connor, Daniel; Martínez, Alejandro; Wurtz, Gregory A; Zayats, Anatoly V

2013-04-19

Wave interference is a fundamental manifestation of the superposition principle with numerous applications. Although in conventional optics, interference occurs between waves undergoing different phase advances during propagation, we show that the vectorial structure of the near field of an emitter is essential for controlling its radiation as it interferes with itself on interaction with a mediating object. We demonstrate that the near-field interference of a circularly polarized dipole results in the unidirectional excitation of guided electromagnetic modes in the near field, with no preferred far-field radiation direction. By mimicking the dipole with a single illuminated slit in a gold film, we measured unidirectional surface-plasmon excitation in a spatially symmetric structure. The surface wave direction is switchable with the polarization.

Rationale and design of the NO-PARTY trial: near-zero fluoroscopic exposure during catheter ablation of supraventricular arrhythmias in young patients.

PubMed

Casella, Michela; Dello Russo, Antonio; Pelargonio, Gemma; Bongiorni, Maria Grazia; Del Greco, Maurizio; Piacenti, Marcello; Andreassi, Maria Grazia; Santangeli, Pasquale; Bartoletti, Stefano; Moltrasio, Massimo; Fassini, Gaetano; Marini, Massimiliano; Di Cori, Andrea; Di Biase, Luigi; Fiorentini, Cesare; Zecchi, Paolo; Natale, Andrea; Picano, Eugenio; Tondo, Claudio

2012-10-01

Radiofrequency catheter ablation is the mainstay of therapy for supraventricular tachyarrhythmias. Conventional radiofrequency catheter ablation requires the use of fluoroscopy, thus exposing patients to ionising radiation. The feasibility and safety of non-fluoroscopic radiofrequency catheter ablation has been recently reported in a wide range of supraventricular tachyarrhythmias using the EnSite NavX™ mapping system. The NO-PARTY is a multi-centre, randomised controlled trial designed to test the hypothesis that catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system results in a clinically significant reduction in exposure to ionising radiation compared with conventional catheter ablation. The study will randomise 210 patients undergoing catheter ablation of supraventricular tachyarrhythmias to either a conventional ablation technique or one guided by the EnSite NavX™ mapping system. The primary end-point is the reduction of the radiation dose to the patient. Secondary end-points include procedural success, reduction of the radiation dose to the operator, and a cost-effectiveness analysis. In a subgroup of patients, we will also evaluate the radiobiological effectiveness of dose reduction by assessing acute chromosomal DNA damage in peripheral blood lymphocytes. NO-PARTY will determine whether radiofrequency catheter ablation of supraventricular tachyarrhythmias guided by the EnSite NavX™ mapping system is a suitable and cost-effective approach to achieve a clinically significant reduction in ionising radiation exposure for both patient and operator.

Reinforcing the role of the conventional C-arm--a novel method for simplified distal interlocking.

PubMed

Windolf, Markus; Schroeder, Josh; Fliri, Ladina; Dicht, Benno; Liebergall, Meir; Richards, R Geoff

2012-01-25

The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR) like setting on human cadaveric lower legs in terms of operating time and radiation exposure. The proposed concept (guided freehand), generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required.Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland). The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests. A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4) (mean ± SD) compared to the freehand technique (17.6 ± 10.3) (p < 0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique compared to conventional freehand (p = 0.001). Operating time per screw (from first shot to screw tightened) was on average 22% reduced by guided freehand (p = 0.018). In an experimental setting, the newly developed guided freehand technique for distal interlocking has proven to markedly reduce radiation exposure when compared to the conventional freehand technique. The method utilizes established clinical workflows and does not require cost intensive add-on devices or extensive training. The underlying principle carries potential to assist implant positioning in numerous other applications within orthopedics and trauma from screw insertions to placement of plates, nails or prostheses.

Experimental validation of tonal noise control from subsonic axial fans using flow control obstructions

NASA Astrophysics Data System (ADS)

Gérard, Anthony; Berry, Alain; Masson, Patrice; Gervais, Yves

2009-03-01

This paper presents the acoustic performance of a novel approach for the passive adaptive control of tonal noise radiated from subsonic fans. Tonal noise originates from non-uniform flow that causes circumferentially varying blade forces and gives rise to a considerably larger radiated dipolar sound at the blade passage frequency (BPF) and its harmonics compared to the tonal noise generated by a uniform flow. The approach presented in this paper uses obstructions in the flow to destructively interfere with the primary tonal noise arising from various flow conditions. The acoustic radiation of the obstructions is first demonstrated experimentally. Indirect on-axis acoustic measurements are used to validate the analytical prediction of the circumferential spectrum of the blade unsteady lift and related indicators generated by the trapezoidal and sinusoidal obstructions presented in Ref. [A. Gérard, A. Berry, P. Masson, Y. Gervais, Modelling of tonal noise control from subsonic axial fans using flow control obstructions, Journal of Sound and Vibration (2008), this issue, doi: 10.1016/j.jsv.2008.09.027.] and also by cylindrical obstructions used in the literature. The directivity and sound power attenuation are then given in free field for the control of the BPF tone generated by rotor/outlet guide vane (OGV) interaction and the control of an amplified BPF tone generated by the rotor/OGV interaction with an added triangular obstruction between two outlet guide vanes to enhance the primary non-uniform flow. Global control was demonstrated in free field, attenuation up to 8.4 dB of the acoustic power at BPF has been measured. Finally, the aerodynamic performances of the automotive fan used in this study are almost not affected by the presence of the control obstruction.

Effectiveness and cost-utility of a guided self-help exercise program for patients treated with total laryngectomy: protocol of a multi-center randomized controlled trial.

PubMed

Jansen, Femke; Cnossen, Ingrid C; Eerenstein, Simone E J; Coupé, Veerle M H; Witte, Birgit I; van Uden-Kraan, Cornelia F; Doornaert, Patricia; Braunius, Weibel W; De Bree, Remco; Hardillo, José A U; Honings, Jimmie; Halmos, György B; Leemans, C René; Verdonck-de Leeuw, Irma M

2016-08-02

Total laryngectomy with or without adjuvant (chemo)radiation often induces speech, swallowing and neck and shoulder problems. Speech, swallowing and shoulder exercises may prevent or diminish these problems. The aim of the present paper is to describe the study, which is designed to investigate the effectiveness and cost-utility of a guided self-help exercise program built into the application "In Tune without Cords" among patients treated with total laryngectomy. Patients, up to 5 years earlier treated with total laryngectomy with or without (chemo)radiation will be recruited for participation in this study. Patients willing to participate will be randomized to the intervention or control group (1:1). Patients in the intervention group will be provided access to a guided self-help exercise program and a self-care education program built into the application "In Tune without Cords". Patients in the control group will only be provided access to the self-care education program. The primary outcome is the difference in swallowing quality (SWAL-QOL) between the intervention and control group. Secondary outcome measures address speech problems (SHI), shoulder disability (SDQ), quality of life (EORTC QLQ-C30, QLQ-H&N35 and EQ-5D), direct and indirect costs (adjusted iMCQ and iPCQ measures) and self-management (PAM). Patients will be asked to complete these outcome measures at baseline, immediately after the intervention or control period (i.e. at 3 months follow-up) and at 6 months follow-up. This randomized controlled trial will provide knowledge on the effectiveness of a guided self-help exercise program for patients treated with total laryngectomy. In addition, information on the value for money of such an exercise program will be provided. If this guided self-help program is (cost)effective for patients treated with total laryngectomy, the next step will be to implement this exercise program in current clinical practice. NTR5255 Protocol version 4 date September 2015.

WE-C-TOUR-I-01: Dosimters for QC in Diagnostic Imaging

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, X.

Tour Leader: Xia Jiang, Ohio State University, Columbus, OH Tour Guides: Xia Jiang, Ohio State University, Columbus, OH Kevin Little, The University of Chicago, Chicago, IL Adrien Sanchez, University of Chicago, Chicago, IL Participating Vendors: IBA PTW - New York Radcal Corporation RTI Electronics, Inc. Exhibit Hall Guided Tours is a new program launching this year at the Annual Meeting. The Guided Tours are designed to enhance the interaction between meeting attendees and exhibitors. This year’s Imaging Guided Tours are organized around the theme of dosimeters for quality control in diagnostic imaging. Tours will begin with an introduction and backgroundmore » given by Dr. Xia Jiang, the Tour Leader. The introduction will cover the types and properties of different radiation dosimeters used for quality assurance in clinical radiology. Attendees will then break into smaller groups, each lead by an AAPM-member Tour Guide. The tour groups will visit the exhibit booths of vendors who provide appropriate dosimeters, and a vendor representative will give a presentation to the group about their particular product(s). The vendor representatives as well as the Tour Guides will be available to answer questions. Outline: Types and properties of radiation detectors and dosimeters Ionization chamber dosimeters Solid state dosimeters Dosimeter calibration: Primary and secondary standards dosimetry laboratories Instruments for measuring tube voltage and exposure time Vendor presentations will likely cover features and innovations of different dosimeter systems, as well as their practical use. Learning Objectives: Understand the types and properties of different instrumentations used for quality control in diagnostic imaging. Understand the process of dosimeter calibration. Gain familiarity with the latest commercial dosimeter systems from different vendors.« less

Clinical Outcomes of Image Guided Adaptive Hypofractionated Weekly Radiation Therapy for Bladder Cancer in Patients Unsuitable for Radical Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hafeez, Shaista, E-mail: shaista.hafeez@icr.ac.uk; The Royal Marsden NHS Foundation Trust, Sutton, Surrey; McDonald, Fiona

Purpose and Objectives: We report on the clinical outcomes of a phase 2 study assessing image guided hypofractionated weekly radiation therapy in bladder cancer patients unsuitable for radical treatment. Methods and Materials: Fifty-five patients with T2-T4aNx-2M0-1 bladder cancer not suitable for cystectomy or daily radiation therapy treatment were recruited. A “plan of the day” radiation therapy approach was used, treating the whole (empty) bladder to 36 Gy in 6 weekly fractions. Acute toxicity was assessed weekly during radiation therapy, at 6 and 12 weeks using the Common Terminology Criteria for Adverse Events version 3.0. Late toxicity was assessed at 6 months and 12 monthsmore » using Radiation Therapy Oncology Group grading. Cystoscopy was used to assess local control at 3 months. Cumulative incidence function was used to determine local progression at 1 at 2 years. Death without local progression was treated as a competing risk. Overall survival was estimated using the Kaplan-Meier method. Results: Median age was 86 years (range, 68-97 years). Eighty-seven percent of patients completed their prescribed course of radiation therapy. Genitourinary and gastrointestinal grade 3 acute toxicity was seen in 18% (10/55) and 4% (2/55) of patients, respectively. No grade 4 genitourinary or gastrointestinal toxicity was seen. Grade ≥3 late toxicity (any) at 6 and 12 months was seen in 6.5% (2/31) and 4.3% (1/23) of patients, respectively. Local control after radiation therapy was 92% of assessed patients (60% total population). Cumulative incidence of local progression at 1 year and 2 years for all patients was 7% (95% confidence interval [CI] 2%-17%) and 17% (95% CI 8%-29%), respectively. Overall survival at 1 year was 63% (95% CI 48%-74%). Conclusion: Hypofractionated radiation therapy delivered weekly with a plan of the day approach offers good local control with acceptable toxicity in a patient population not suitable for radical bladder treatment.« less

Contribution of radiation chemistry to the study of metal clusters.

PubMed

Belloni, J

1998-11-01

Radiation chemistry dates from the discovery of radioactivity one century ago by H. Becquerel and P. and M. Curie. The complex phenomena induced by ionizing radiation have been explained progressively. At present, the methodology of radiation chemistry, particularly in the pulsed mode, provides a powerful means to study not only the early processes after the energy absorption, but more generally a broad diversity of chemical and biochemical reaction mechanisms. Among them, the new area of metal cluster chemistry illustrates how radiation chemistry contributed to this field in suggesting fruitful original concepts, in guiding and controlling specific syntheses, and in the detailed elaboration of the mechanisms of complex and long-unsolved processes, such as the dynamics of nucleation, electron transfer catalysis and photographic development.

Strategies for optimizing the response of cancer and normal tissues to radiation

PubMed Central

Moding, Everett J.; Kastan, Michael B.; Kirsch, David G.

2014-01-01

Approximately 50% of all patients with cancer receive radiation therapy at some point during the course of their treatment, and the majority of these patients are treated with curative intent. Despite recent advances in the planning of radiation treatment and the delivery of image-guided radiation therapy, acute toxicity and potential long-term side effects often limit the ability to deliver a sufficient dose of radiation to control tumours locally. In the past two decades, a better understanding of the hallmarks of cancer and the discovery of specific signalling pathways by which cells respond to radiation have provided new opportunities to design molecularly targeted therapies to increase the therapeutic window of radiation therapy. Here, we review efforts to develop approaches that could improve outcomes with radiation therapy by increasing the probability of tumour cure or by decreasing normal tissue toxicity. PMID:23812271

MO-B-201-00: Motion Management in Current Stereotactic Body Radiation Therapy (SBRT) Practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The motion management in stereotactic body radiation therapy (SBRT) is a key to success for a SBRT program, and still an on-going challenging task. A major factor is that moving structures behave differently than standing structures when examined by imaging modalities, and thus require special considerations and employments. Understanding the motion effects to these different imaging processes is a prerequisite for a decent motion management program. The commonly used motion control techniques to physically restrict tumor motion, if adopted correctly, effectively increase the conformity and accuracy of hypofractionated treatment. The effective application of such requires one to understand the mechanicsmore » of the application and the related physiology especially related to respiration. The image-guided radiation beam control, or tumor tracking, further realized the endeavor for precision-targeting. During tumor tracking, the respiratory motion is often constantly monitored by non-ionizing beam sources using the body surface as its surrogate. This then has to synchronize with the actual internal tumor motion. The latter is often accomplished by stereo X-ray imaging or similar techniques. With these advanced technologies, one may drastically reduce the treated volume and increase the clinicians’ confidence for a high fractional ablative radiation dose. However, the challenges in implementing the motion management may not be trivial and is dependent on each clinic case. This session of presentations is intended to provide an overview of the current techniques used in managing the tumor motion in SBRT, specifically for routine lung SBRT, proton based treatments, and newly-developed MR guided RT. Learning Objectives: Through this presentation, the audience will understand basic roles of commonly used imaging modalities for lung cancer studies; familiarize the major advantages and limitations of each discussed motion control methods; familiarize the major advantages and limitations of each discussed radiation beam control methodology and tumor tacking method; understand the key points in motion management for a high quality SBRT program.« less

Clinical applications of image guided-intensity modulated radiation therapy (IG-IMRT) for conformal avoidance of normal tissue

NASA Astrophysics Data System (ADS)

Gutierrez, Alonso Navar

2007-12-01

Recent improvements in imaging technology and radiation delivery have led to the development of advanced treatment techniques in radiotherapy which have opened the door for novel therapeutic approaches to improve the efficacy of radiation cancer treatments. Among these advances is image-guided, intensity modulated radiation therapy (IG-IMRT), in which imaging is incorporated to aid in inter-/intra-fractional target localization and to ensure accurate delivery of precise and highly conformal dose distributions. In principle, clinical implementation of IG-IMRT should improve normal tissue sparing and permit effective biological dose escalation thus widening the radiation therapeutic window and lead to increases in survival through improved local control of primary neoplastic diseases. Details of the development of three clinical applications made possible solely with IG-IMRT radiation delivery techniques are presented: (1) Laparoscopically implanted tissue expander radiotherapy (LITE-RT) has been developed to enhance conformal avoidance of normal tissue during the treatment of intra-abdominopelvic cancers. LITE-RT functions by geometrically displacing surrounding normal tissue and isolating the target volume through the interfractional inflation of a custom-shaped tissue expander throughout the course of treatment. (2) The unique delivery geometry of helical tomotherapy, a novel form of IG-IMRT, enables the delivery of composite treatment plan m which whole brain radiotherapy (WBRT) with hippocampal avoidance, hypothesized to reduce the risk of memory function decline and improve the patient's quality of life, and simultaneously integrated boost to multiple brain metastases to improve intracranial tumor control is achieved. (3) Escalation of biological dose to targets through integrated, selective subvolume boosts have been shown to efficiently increase tumor dose without significantly increasing normal tissue dose. Helical tomotherapy was used to investigate the feasibility of delivering a simultaneously integrated subvolume boost to canine nasal tumors and was found to dramatically increase estimated 1-year tumor control probability (TCP) without increasing the dose to the eyes, so as to preserve vision, and to the brain, so as to prevent neuropathy.

MR-guided radiation therapy: transformative technology and its role in the central nervous system

PubMed Central

Tseng, Chia-Lin; Balter, James M.; Teng, Feifei; Parmar, Hemant A.; Sahgal, Arjun

2017-01-01

Abstract This review article describes advancement of magnetic resonance imaging technologies in radiation therapy planning, guidance, and adaptation of brain tumors. The potential for MR-guided radiation therapy to improve outcomes and the challenges in its adoption are discussed. PMID:28380637

Radiation detection system

DOEpatents

Nelson, Melvin A.; Davies, Terence J.; Morton, III, John R.

1976-01-01

A radiation detection system which utilizes the generation of Cerenkov light in and the transmission of that light longitudinally through fiber optic wave guides in order to transmit intelligence relating to the radiation to a remote location. The wave guides are aligned with respect to charged particle radiation so that the Cerenkov light, which is generated at an angle to the radiation, is accepted by the fiber for transmission therethrough. The Cerenkov radiation is detected, recorded, and analyzed at the other end of the fiber.

Reinforcing the role of the conventional C-arm - a novel method for simplified distal interlocking

PubMed Central

2012-01-01

Background The common practice for insertion of distal locking screws of intramedullary nails is a freehand technique under fluoroscopic control. The process is technically demanding, time-consuming and afflicted to considerable radiation exposure of the patient and the surgical personnel. A new concept is introduced utilizing information from within conventional radiographic images to help accurately guide the surgeon to place the interlocking bolt into the interlocking hole. The newly developed technique was compared to conventional freehand in an operating room (OR) like setting on human cadaveric lower legs in terms of operating time and radiation exposure. Methods The proposed concept (guided freehand), generally based on the freehand gold standard, additionally guides the surgeon by means of visible landmarks projected into the C-arm image. A computer program plans the correct drilling trajectory by processing the lens-shaped hole projections of the interlocking holes from a single image. Holes can be drilled by visually aligning the drill to the planned trajectory. Besides a conventional C-arm, no additional tracking or navigation equipment is required. Ten fresh frozen human below-knee specimens were instrumented with an Expert Tibial Nail (Synthes GmbH, Switzerland). The implants were distally locked by performing the newly proposed technique as well as the conventional freehand technique on each specimen. An orthopedic resident surgeon inserted four distal screws per procedure. Operating time, number of images and radiation time were recorded and statistically compared between interlocking techniques using non-parametric tests. Results A 58% reduction in number of taken images per screw was found for the guided freehand technique (7.4 ± 3.4) (mean ± SD) compared to the freehand technique (17.6 ± 10.3) (p < 0.001). Total radiation time (all 4 screws) was 55% lower for the guided freehand technique compared to conventional freehand (p = 0.001). Operating time per screw (from first shot to screw tightened) was on average 22% reduced by guided freehand (p = 0.018). Conclusions In an experimental setting, the newly developed guided freehand technique for distal interlocking has proven to markedly reduce radiation exposure when compared to the conventional freehand technique. The method utilizes established clinical workflows and does not require cost intensive add-on devices or extensive training. The underlying principle carries potential to assist implant positioning in numerous other applications within orthopedics and trauma from screw insertions to placement of plates, nails or prostheses. PMID:22276698

Precision Oncology and Genomically Guided Radiation Therapy: A Report From the American Society for Radiation Oncology/American Association of Physicists in Medicine/National Cancer Institute Precision Medicine Conference.

PubMed

Hall, William A; Bergom, Carmen; Thompson, Reid F; Baschnagel, Andrew M; Vijayakumar, Srinivasan; Willers, Henning; Li, X Allen; Schultz, Christopher J; Wilson, George D; West, Catharine M L; Capala, Jacek; Coleman, C Norman; Torres-Roca, Javier F; Weidhaas, Joanne; Feng, Felix Y

2018-06-01

To summarize important talking points from a 2016 symposium focusing on real-world challenges to advancing precision medicine in radiation oncology, and to help radiation oncologists navigate the practical challenges of precision, radiation oncology. The American Society for Radiation Oncology, American Association of Physicists in Medicine, and National Cancer Institute cosponsored a meeting on precision medicine in radiation oncology. In June 2016 numerous scientists, clinicians, and physicists convened at the National Institutes of Health to discuss challenges and future directions toward personalized radiation therapy. Various breakout sessions were held to discuss particular components and approaches to the implementation of personalized radiation oncology. This article summarizes the genomically guided radiation therapy breakout session. A summary of existing genomic data enabling personalized radiation therapy, ongoing clinical trials, current challenges, and future directions was collected. The group attempted to provide both a current overview of data that radiation oncologists could use to personalize therapy, along with data that are anticipated in the coming years. It seems apparent from the provided review that a considerable opportunity exists to truly bring genomically guided radiation therapy into clinical reality. Genomically guided radiation therapy is a necessity that must be embraced in the coming years. Incorporating these data into treatment recommendations will provide radiation oncologists with a substantial opportunity to improve outcomes for numerous cancer patients. More research focused on this topic is needed to bring genomic signatures into routine standard of care. Published by Elsevier Inc.

Adopting Ultrasound Guidance for Prone Percutaneous Nephrolithotomy: Evaluating the Learning Curve for the Experienced Surgeon

PubMed Central

Usawachintachit, Manint; Masic, Selma; Allen, Isabel E.; Li, Jianxing

2016-01-01

Abstract Objectives: To define the learning curve associated with adopting ultrasound guidance for prone percutaneous nephrolithotomy (PCNL) for the experienced surgeon. Methods: A prospective cohort study of consecutive patients undergoing PCNL with ultrasound guidance for renal tract access and dilation was performed. Clinical data reviewed included success in gaining renal access with ultrasound guidance, total fluoroscopic screening time, and radiation exposure dose. PCNL cases performed with fluoroscopic guidance matched for stone size served as control cases. Results: One hundred consecutive ultrasound-guided procedures performed by a single experienced endourologist were divided into five experience groups. Significant improvement in renal access success rate with ultrasound was seen after 20 cases (p < 0.05). Total fluoroscopic screening time, radiation exposure dose, and operative time were also statistically significantly improved over the study period. When compared with fluoroscopy-guided PCNL, significant decreases in total fluoroscopic screening time (33.4 ± 35.3 seconds vs 157.5 ± 84.9 seconds, p < 0.05) and radiation exposure (7.0 ± 8.7 mGy vs 47.8 ± 45.9 mGy, p < 0.05) were seen. No differences in complication rates were found. Conclusions: Ultrasound-guided renal access for PCNL can be performed effectively after 20 cases. Transition to the use of ultrasound will quickly reduce radiation exposure for patients and intraoperative personnel. PMID:27150671

[Image-guided radiotherapy and partial delegation to radiotherapy technicians: Clermont-Ferrand experience].

PubMed

Loos, G; Moreau, J; Miroir, J; Benhaïm, C; Biau, J; Caillé, C; Bellière, A; Lapeyre, M

2013-10-01

The various image-guided radiotherapy techniques raise the question of how to achieve the control of patient positioning before irradiation session and sharing of tasks between radiation oncologists and radiotherapy technicians. We have put in place procedures and operating methods to make a partial delegation of tasks to radiotherapy technicians and secure the process in three situations: control by orthogonal kV imaging (kV-kV) of bony landmarks, control by kV-kV imaging of intraprostatic fiducial goldmarkers and control by cone beam CT (CBCT) imaging for prostate cancer. Significant medical overtime is required to control these three IGRT techniques. Because of their competence in imaging, these daily controls can be delegated to radiotherapy technicians. However, to secure the process, initial training and regular evaluation are essential. The analysis of the comparison of the use of kV/kV on bone structures allowed us to achieve a partial delegation of control to radiotherapy technicians. Controlling the positioning of the prostate through the use and automatic registration of fiducial goldmarkers allows better tracking of the prostate and can be easily delegated to radiotherapy technicians. The analysis of the use of daily cone beam CT for patients treated with intensity modulated irradiation is underway, and a comparison of practices between radiotherapy technicians and radiation oncologists is ongoing to know if a partial delegation of this control is possible. Copyright © 2013. Published by Elsevier SAS.

Development of Low-Cost Method for Fabrication of Metal Neutron Guides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelhaupt, Darell; Khaykovich, Boris; Romaine, Suzanne

Neutron scattering is one of the most useful methods of studying the structure and dynamics of matter. US DOE neutron scattering research facilities at Oak Ridge National Laboratory are among the World’s most advanced, providing researchers with unmatched capabilities for probing the structure and properties of materials, including engineering and biological systems. This task is to develop a lower cost process to optimize and produce the required neutron guides capable of efficiently delivering neutron beams for tens of meters between neutron moderators and instruments. Therefore, our effort is to improve the performance and lower the production cost of neutron guides.more » Our approach aims at improving guide quality while controlling their rising costs by adopting a novel electroforming replication approach to their fabrication. These guides will be especially advantageous when used near the neutron source since the radiation resistance of nickel is superior to glass. Additionally, we are depositing low-stress nickel from an extremely low impurity solution completely free of stress-reducing agents, which nominally contain and impart sulfur, carbon and other elements that potentially activate in the neutron environment. This is achieved by using a pulsed periodically reversed current methodology. The best guides quote waviness of 0.1 mrad. It is reasonable to prepare just one mandrel of about 0.5 m long, for production of tens of guide segments, saving both the cost and supply time of guides to neutron facilities. We estimate that we can fabricate a single mandrel for the current cost of an individual one-meter guide, but from this, we can produce tens of meters of guide very inexpensively without mandrel refurbishment. While a multilayer coating will add to the overall cost, we expect this will be less than that of commercially available guides today. Therefore, we will produce higher quality guides, which are less susceptible to radiation damage, at the lower cost than those available today.« less

Development of Low-Cost Method for Fabrication of Metal Neutron Guides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Engelhaupt, Darell; Khaykovich, Boris; Romaine, Suzanne

2017-12-19

Neutron scattering is one of the most useful methods of studying the structure and dynamics of matter. US DOE neutron scattering research facilities at Oak Ridge National Laboratory are among the World’s most advanced, providing researchers with unmatched capabilities for probing the structure and properties of materials, including engineering and biological systems. This task is to develop a lower cost process to optimize and produce the required neutron guides capable of efficiently delivering neutron beams for tens of meters between neutron moderators and instruments. Therefore, our effort is to improve the performance and lower the production cost of neutron guides.more » Our approach aims at improving guide quality while controlling their rising costs by adopting a novel electroforming replication approach to their fabrication. These guides will be especially advantageous when used near the neutron source since the radiation resistance of nickel is superior to glass. Additionally, we are depositing low-stress nickel from an extremely low impurity solution completely free of stress-reducing agents, which nominally contain and impart sulfur, carbon and other elements that potentially activate in the neutron environment. This is achieved by using a pulsed periodically reversed current methodology. The best guides quote waviness of 0.1 mrad. It is reasonable to prepare just one mandrel of about 0.5 m long, for production of tens of guide segments, saving both the cost and supply time of guides to neutron facilities. We estimate that we can fabricate a single mandrel for the current cost of an individual one-meter guide, but from this, we can produce tens of meters of guide very inexpensively without mandrel refurbishment. While a multilayer coating will add to the overall cost, we expect this will be less than that of commercially available guides today. Therefore, we will produce higher quality guides, which are less susceptible to radiation damage, at the lower cost than those available today.« less

INTERNATIONAL CONFERENCE ON SEMICONDUCTOR INJECTION LASERS SELCO-87: Behavior of gain-guided lasers generating high-power nanosecond pulses

NASA Astrophysics Data System (ADS)

Erbert, G.

1988-11-01

Computer-controlled apparatus was used in an investigation of gain-guided narrow-stripe AlGaAs double heterostructure lasers. These lasers were excited with current pulses of 10 ns duration and amplitudes up to 3 A. The watt-ampere characteristics together with near- and far-field radiation patterns were considered using an analytic model of the lasers. The results showed that the values of the gain under a stripe contact or of the absorption outside this region varied with the output power.

[Interest of positioning control in onboard imaging and its delegation to the therapists].

PubMed

de Crevoisier, R; Duvergé, L; Hulot, C; Chauvet, B; Henry, O; Bouvet, C; Castelli, J

2016-10-01

The delegation of the on board imaging position control, from the radiation oncologist to the therapist, is justified by the generalization of the image-guided radiotherapy techniques which are particularly time consuming. This delegation is however partial. Indeed, the validation of the position by the therapist can be clearly performed when the registration is based on bony landmark or fiducial. The radiation oncologist needs however to make the validation in case of large target displacement, in more complex soft tissue-based registration, and in case of stereotactic body radiation therapy. Moreover, this delegation implies at least three conditions which are first the training of the staff, then the formalization of the procedures, responsibilities and delegations and finally, the evaluation of the practices of IGRT. Copyright © 2016. Published by Elsevier SAS.

SU-E-I-39: Molecular Image Guided Cancer Stem Cells Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Abdollahi, H

Purpose: Cancer stem cells resistance to radiation is a problematic issue that has caused a big fail in cancer treatment. Methods: As a primary work, molecular imaging can indicate the main mechanisms of radiation resistance of cancer stem cells. By developing and commissioning new probes and nanomolecules and biomarkers, radiation scientist will able to identify the essential pathways of radiation resistance of cancer stem cells. As the second solution, molecular imaging is a best way to find biological target volume and delineate cancer stem cell tissues. In the other hand, by molecular imaging techniques one can image the treatment responsemore » in tumor and also in normal tissue. In this issue, the response of cancer stem cells to radiation during therapy course can be imaged, also the main mechanisms of radiation resistance and finding the best radiation modifiers (sensitizers) can be achieved by molecular imaging modalities. In adaptive radiotherapy the molecular imaging plays a vital role to have higher tumor control probability by delivering high radiation doses to cancer stem cells in any time of treatment. The outcome of a feasible treatment is dependent to high cancer stem cells response to radiation and removing all of which, so a good imaging modality can show this issue and preventing of tumor recurrence and metastasis. Results: Our results are dependent to use of molecular imaging as a new modality in the clinic. We propose molecular imaging as a new radiobiological technique to solve radiation therapy problems due to cancer stem cells. Conclusion: Molecular imaging guided cancer stem cell diagnosis and therapy is a new approach in the field of cancer treatment. This new radiobiological imaging technique should be developed in all clinics as a feasible tool that is more biological than physical imaging.« less

Radiation Dose Reduction in CT Fluoroscopy-Guided Cervical Transforaminal Epidural Steroid Injection by Modifying Scout and Planning Steps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paik, Nam Chull, E-mail: pncspine@gmail.com

Background and PurposeIn CT fluoroscopy (CTF)-guided cervical transforaminal epidural steroid injection (TFESI), the majority of radiation dose is contributed by the planning CT scan rather than the CTF procedure itself. We replaced the planning helical CT with a spot CTF and accordingly changed the patient posture during scout and planning scans. The aim of this study was to test whether radiation dose reduction would be achieved by this protocol modification while still maintaining technical performance.MethodsOverall, 338 consecutive procedures before (control group: n = 163) and after (study group: n = 175) instituting the above-mentioned protocol modification were analyzed retrospectively, comparing patient characteristics (age, sex,more » neck diameter, and level injected) and technical performance [technical success rate, dose-length product (DLP), inadvertent contrast flow incidence, number of CTF acquisitions, and procedural time] between the two groups.ResultsAll injections were technically successful at every level from C3–C4 to C7–T1 without serious complications in both groups. The median DLP of the study group (7.92 mGy·cm) was significantly reduced compared to that of the control group (39.05 mGy·cm, P < 0.001). There were no significant differences between the two groups regarding the incidence of inadvertent contrast flow (20.6 vs. 17.2 %, P = 0.426), number of CTF acquisitions (median 5 vs. 4, P = 0.123), and the procedural time (median 6.62 vs. 6.90 min, P = 0.100).ConclusionsWhen conducting CTF-guided cervical TFESIs, a significant radiation dose reduction (median 79.7 % in DLP) can be achieved by modifying scout and planning steps, without compromising the technical performance.« less

Safety and Efficacy of Modified Preoperative Lung Nodule Microcoil Localization Without Pleural Marking: A Pilot Study.

PubMed

Kha, Lan-Chau T; Hanneman, Kate; Donahoe, Laura; Chung, Taebong; Pierre, Andrew F; Yasufuku, Kazuhiro; Keshavjee, Shafique; Mayo, John R; Paul, Narinder S; Nguyen, Elsie T

2016-01-01

The purpose of this pilot study was to evaluate the safety and efficacy of preoperative computed tomography (CT)-guided percutaneous microcoil lung nodule localization without pleural marking compared with the established technique with pleural marking. Sixty-three consecutive patients (66.7% female, mean age 61.6±11.4 y) with 64 lung nodules resected between October 2008 and January 2014 were retrospectively evaluated. Of the nodules, 29.7% (n=19) had microcoil deployment with pleural marking (control group) and 70.3% (n=45) had microcoil deployment without pleural marking (pilot group). Clinical, pathologic, and imaging characteristics, radiation dose, CT procedure and operating room time, and complete resection and complication rates were compared between the pilot and control groups. There was no significant difference in nodule size (P=0.552) or distance from the pleural surface (P=0.222) between the pilot and control groups. However, mean procedure duration (53.6±18.3 vs. 72.8±25.3 min, P=0.001) and total effective radiation dose (5.1±2.6 vs. 7.1±4.9 mSv, P=0.039) were significantly lower in the pilot group compared with the control group. CT procedure-related complications (P=0.483) [including pneumothoraces (P=0.769) and pulmonary hemorrhage (P=1.000)], operating room time (P=0.926), complete resection rates (P=0.520), intraoperative complications (P=0.549), and postoperative complications (P=1.000) were similar between the pilot and control groups. Preoperative CT-guided lung nodule microcoil localization performed without visceral pleural marking appears to decrease the CT procedure time and radiation dose while maintaining equivalent complete resection rates and procedural and surgical complications, when compared with microcoil localization performed with pleural marking.

Extracting concentrated guided light.

PubMed

Ries, H; Segal, A; Karni, J

1997-05-01

The maximum concentration of radiation is proportional to the square of the refractive index of the medium in which it propagates. A medium with a high refractive index can also serve as a lightguide for concentrated radiation. However, if concentrated radiation is extracted from one medium, with a high refractive index, to another, whose index is lower (e.g., from fused silica into air), part of the radiation may be lost because of the total internal reflection at the interface. We present polygonal shapes suitable for efficient extraction of the concentrated radiation in a controllable way, without increasing the cross-section area (or diameter) of the lightguide. It is shown analytically and experimentally that the use of a secondary concentrator, followed by such a light extractor, both having a high refractive index, can provide considerably more power to a solar receiver with a specific aperture.

Nuclear Technology Series. Radiation Protection Technician. A Suggested Program Planning Guide. Revised June 80.

ERIC Educational Resources Information Center

Center for Occupational Research and Development, Inc., Waco, TX.

This program planning guide for a two-year postsecondary radiation protection technician program is designed for use with courses 17-22 of thirty-five included in the Nuclear Technology Series. The purpose of the guide is to describe the nuclear power field and its job categories for specialists, technicians, and operators; and to assist planners,…

User's Guide for ERB 7 Matrix. Volume 1: Experiment Description and Quality Control Report for Year 1

NASA Technical Reports Server (NTRS)

Tighe, R. J.; Shen, M. Y. H.

1984-01-01

The Nimbus 7 ERB MATRIX Tape is a computer program in which radiances and irradiances are converted into fluxes which are used to compute the basic scientific output parameters, emitted flux, albedo, and net radiation. They are spatially averaged and presented as time averages over one-day, six-day, and monthly periods. MATRIX data for the period November 16, 1978 through October 31, 1979 are presented. Described are the Earth Radiation Budget experiment, the Science Quality Control Report, Items checked by the MATRIX Science Quality Control Program, and Science Quality Control Data Analysis Report. Additional material from the detailed scientific quality control of the tapes which may be very useful to a user of the MATRIX tapes is included. Known errors and data problems and some suggestions on how to use the data for further climatologic and atmospheric physics studies are also discussed.

Maywood interim storage site. Annual site environmental report, calendar year 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-05-01

During 1985, the environmental monitoring program was continued at the Maywood Interim Storage Site (MISS), a US Department of Energy (DOE) facility located in the Borough of Maywood and the Township of Rochelle Park, New Jersey. The MISS is presently used for the storage of low-level radioactively contaminated soils. Monitoring results show that the MISS is in compliance with DOE concentration guides and radiation protection standards. Derived Concentration Guides (DCGs) represent the concentrations of radionuclides in air or water that would limit the radiation dose to 100 mrem/yr. The applicable guides have been revised since the 1984 environmental monitoring reportmore » was published. The guides applied in 1984 were based on a radiation protection standard of 500 mrem/yr; the guides applied for 1985 are based on a standard of 100 mrem/yr.« less

Endobronchial ultrasound-guided transbronchial needle injection for local control of recurrent non-small cell lung cancer.

PubMed

Khan, Farrah; Anker, Christopher J; Garrison, Garth; Kinsey, C Matthew

2015-01-01

Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is an established technique for the diagnosis of thoracic malignancies. Non-ultrasound-guided transbronchial needle injection has been used previously to deliver chemotherapeutic agents. To use endobronchial ultrasound-guided transbronchial needle injection (EBUS-TBNI) to achieve local control of recurrent early-stage lung cancer. A 63-year-old man presented with recurrent early stage non-small cell lung carcinoma after chemotherapy and external beam radiation. We used EBUS-TBNI to deliver cisplatin into the tumor located outside the airway. This procedure was performed on three separate occasions without complication. EBUS-TBNI resulted in resolution of fluorodeoxyglucose avidity, measured by positron emission tomography-computed tomography, in the region at 4 weeks. However, at 5 months, there was evidence of distal recurrence. This is the first description of EBUS-TBNI to treat local recurrence of lung cancer and one of the first reports of the use of EBUS for intratumoral therapy. Additional research is warranted to determine the clinical usefulness and safety of this therapeutic approach.

Plasmonic mode converter for controlling optical impedance and nanoscale light-matter interaction.

PubMed

Hung, Yun-Ting; Huang, Chen-Bin; Huang, Jer-Shing

2012-08-27

To enable multiple functions of plasmonic nanocircuits, it is of key importance to control the propagation properties and the modal distribution of the guided optical modes such that their impedance matches to that of nearby quantum systems and desired light-matter interaction can be achieved. Here, we present efficient mode converters for manipulating guided modes on a plasmonic two-wire transmission line. The mode conversion is achieved through varying the path length, wire cross section and the surrounding index of refraction. Instead of pure optical interference, strong near-field coupling of surface plasmons results in great momentum splitting and modal profile variation. We theoretically demonstrate control over nanoantenna radiation and discuss the possibility to enhance nanoscale light-matter interaction. The proposed converter may find applications in surface plasmon amplification, index sensing and enhanced nanoscale spectroscopy.

MO-B-201-01: Overcoming the Challenges of Motion Management in Current Lung SBRT Practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shang, C.

The motion management in stereotactic body radiation therapy (SBRT) is a key to success for a SBRT program, and still an on-going challenging task. A major factor is that moving structures behave differently than standing structures when examined by imaging modalities, and thus require special considerations and employments. Understanding the motion effects to these different imaging processes is a prerequisite for a decent motion management program. The commonly used motion control techniques to physically restrict tumor motion, if adopted correctly, effectively increase the conformity and accuracy of hypofractionated treatment. The effective application of such requires one to understand the mechanicsmore » of the application and the related physiology especially related to respiration. The image-guided radiation beam control, or tumor tracking, further realized the endeavor for precision-targeting. During tumor tracking, the respiratory motion is often constantly monitored by non-ionizing beam sources using the body surface as its surrogate. This then has to synchronize with the actual internal tumor motion. The latter is often accomplished by stereo X-ray imaging or similar techniques. With these advanced technologies, one may drastically reduce the treated volume and increase the clinicians’ confidence for a high fractional ablative radiation dose. However, the challenges in implementing the motion management may not be trivial and is dependent on each clinic case. This session of presentations is intended to provide an overview of the current techniques used in managing the tumor motion in SBRT, specifically for routine lung SBRT, proton based treatments, and newly-developed MR guided RT. Learning Objectives: Through this presentation, the audience will understand basic roles of commonly used imaging modalities for lung cancer studies; familiarize the major advantages and limitations of each discussed motion control methods; familiarize the major advantages and limitations of each discussed radiation beam control methodology and tumor tacking method; understand the key points in motion management for a high quality SBRT program.« less

MO-B-201-02: Motion Management for Proton Lung SBR

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flampouri, S.

The motion management in stereotactic body radiation therapy (SBRT) is a key to success for a SBRT program, and still an on-going challenging task. A major factor is that moving structures behave differently than standing structures when examined by imaging modalities, and thus require special considerations and employments. Understanding the motion effects to these different imaging processes is a prerequisite for a decent motion management program. The commonly used motion control techniques to physically restrict tumor motion, if adopted correctly, effectively increase the conformity and accuracy of hypofractionated treatment. The effective application of such requires one to understand the mechanicsmore » of the application and the related physiology especially related to respiration. The image-guided radiation beam control, or tumor tracking, further realized the endeavor for precision-targeting. During tumor tracking, the respiratory motion is often constantly monitored by non-ionizing beam sources using the body surface as its surrogate. This then has to synchronize with the actual internal tumor motion. The latter is often accomplished by stereo X-ray imaging or similar techniques. With these advanced technologies, one may drastically reduce the treated volume and increase the clinicians’ confidence for a high fractional ablative radiation dose. However, the challenges in implementing the motion management may not be trivial and is dependent on each clinic case. This session of presentations is intended to provide an overview of the current techniques used in managing the tumor motion in SBRT, specifically for routine lung SBRT, proton based treatments, and newly-developed MR guided RT. Learning Objectives: Through this presentation, the audience will understand basic roles of commonly used imaging modalities for lung cancer studies; familiarize the major advantages and limitations of each discussed motion control methods; familiarize the major advantages and limitations of each discussed radiation beam control methodology and tumor tacking method; understand the key points in motion management for a high quality SBRT program.« less

Synthetic guide star generation

DOEpatents

Payne, Stephen A [Castro Valley, CA; Page, Ralph H [Castro Valley, CA; Ebbers, Christopher A [Livermore, CA; Beach, Raymond J [Livermore, CA

2008-06-10

A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

Synthetic guide star generation

DOEpatents

Payne, Stephen A.; Page, Ralph H.; Ebbers, Christopher A.; Beach, Raymond J.

2004-03-09

A system for assisting in observing a celestial object and providing synthetic guide star generation. A lasing system provides radiation at a frequency at or near 938 nm and radiation at a frequency at or near 1583 nm. The lasing system includes a fiber laser operating between 880 nm and 960 nm and a fiber laser operating between 1524 nm and 1650 nm. A frequency-conversion system mixes the radiation and generates light at a frequency at or near 589 nm. A system directs the light at a frequency at or near 589 nm toward the celestial object and provides synthetic guide star generation.

The Department of Defense Very High Speed Integrated Circuit (VHSIC) Technology Availability Program Plan for the Committees on Armed Services United States Congress.

DTIC Science & Technology

1986-06-30

features of computer aided design systems and statistical quality control procedures that are generic to chip sets and processes. RADIATION HARDNESS -The...System PSP Programmable Signal Processor SSI Small Scale Integration ." TOW Tube Launched, Optically Tracked, Wire Guided TTL Transistor Transitor Logic

Impact of the 1980 BEIR-III report on low-level radiation risk assessment, radiation protection guides, and public health policy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fabrikant, J.I.

1981-06-01

The author deals with the scientific basis for establishing appropriate radiation protection guides, and this effect on evaluation of societal activities concerned with the health effects in human populations exposed to low-level radiation. Methodology is discussed for estimating risks of radio-induced cancer and genetically related ill-health in man, the sources of data, the dose-response models used, and the precision ascribed to the process. (PSB)

Brachytherapy of prostate cancer after colectomy for colorectal cancer: pilot experience.

PubMed

Koutrouvelis, Panos G; Theodorescu, Dan; Katz, Stuart; Lailas, Niko; Hendricks, Fred

2005-01-01

We present a method of brachytherapy for prostate cancer using a 3-dimensional stereotactic system and computerized tomography guidance in patients without a rectum due to previous treatment for colorectal cancer. From June 1994 to November 2003 a cohort of 800 patients were treated with brachytherapy for prostate cancer. Four patients had previously been treated for colorectal cancer with 4,500 cGy external beam radiation therapy, abdominoperineal resection and chemotherapy, while 1 underwent abdominoperineal resection alone for ulcerative colitis. Because of previous radiation therapy, these patients were not candidates for salvage external beam radiation therapy or radical prostatectomy and they had no rectum for transrectal ultrasound guided transperineal brachytherapy or cryotherapy. A previously described, 3-dimensional stereotactic system was used for brachytherapy in these patients. The prescribed radiation dose was 120 to 144 Gy with iodine seeds in rapid strand format. Patient followup included clinical examination and serum prostate specific antigen measurement. Average followup was 18.6 months. Four patients had excellent biochemical control, while 1 had biochemical failure. Patients did not experience any gastrointestinal morbidity. One patient had a stricture of the distal ureter, requiring a stent. Three-dimensional computerized tomography guided brachytherapy for prostate cancer in patients with a history of colorectal cancer who have no rectum is a feasible method of treatment.

Nodal Clearance Rate and Long-Term Efficacy of Individualized Sentinel Node–Based Pelvic Intensity Modulated Radiation Therapy for High-Risk Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Müller, Arndt-Christian, E-mail: arndt-christian.mueller@med.uni-tuebingen.de; Eckert, Franziska; Paulsen, Frank

2016-02-01

Purpose: To assess the efficacy of individual sentinel node (SN)-guided pelvic intensity modulated radiation therapy (IMRT) by determining nodal clearance rate [(n expected nodal involvement − n observed regional recurrences)/n expected nodal involvement] in comparison with surgically staged patients. Methods and Materials: Data on 475 high-risk prostate cancer patients were examined. Sixty-one consecutive patients received pelvic SN-based IMRT (5 × 1.8 Gy/wk to 50.4 Gy [pelvic nodes + individual SN] and an integrated boost with 5 × 2.0 Gy/wk to 70.0 Gy to prostate + [base of] seminal vesicles) and neo-/adjuvant long-term androgen deprivation therapy; 414 patients after SN–pelvic lymph node dissection were used to calculate the expected nodal involvement rate for the radiation therapymore » sample. Biochemical control and overall survival were estimated for the SN-IMRT patients using the Kaplan-Meier method. The expected frequency of nodal involvement in the radiation therapy group was estimated by imputing frequencies of node-positive patients in the surgical sample to the pattern of Gleason, prostate-specific antigen, and T category in the radiation therapy sample. Results: After a median follow-up of 61 months, 5-year OS after SN-guided IMRT reached 84.4%. Biochemical control according to the Phoenix definition was 73.8%. The nodal clearance rate of SN-IMRT reached 94%. Retrospective follow-up evaluation is the main limitation. Conclusions: Radiation treatment of pelvic nodes individualized by inclusion of SNs is an effective regional treatment modality in high-risk prostate cancer patients. The pattern of relapse indicates that the SN-based target volume concept correctly covers individual pelvic nodes. Thus, this SN-based approach justifies further evaluation, including current dose-escalation strategies to the prostate in a larger prospective series.« less

Salvage image guided radiation therapy to the prostate after cryotherapy failure.

PubMed

Hopper, Austin B; Sandhu, Ajay P S; Parsons, J Kellogg; Rose, Brent; Einck, John P

2018-01-01

Cryotherapy is an option for the primary treatment of localized prostate cancer, along with radical prostatectomy, external beam radiation therapy, and brachytherapy. Although it is known that local recurrence can occur in >20% of patients treated with primary cryotherapy, unfortunately there is a paucity of data on later salvage treatments. The use of external beam radiation therapy is an attractive option after cryotherapy failure, but there is little data on its efficacy and toxicity. We evaluated the biochemical control and complication rates of salvage dose-escalated image guided intensity modulated radiation therapy (IG-IMRT) after cryotherapy failure. Patients who were treated at our institution from 2005 to 2016 were reviewed for those who underwent cryotherapy as initial treatment followed by salvage IGRT. Patients were treated with dose-escalated IG-IMRT using standard treatment margins of 3 mm posterior and 7 mm in all other directions and daily cone beam computed tomography or kv imaging to implanted fiducial markers. Biochemical progression was defined in accordance with the Phoenix consensus conference definition. Eight patients were identified as having received post-cryotherapy salvage radiation within the study period. The median total dose was 77.7 Gy (range, 75.6-81.0 Gy). Median follow-up was 55 months (range, 6-88 months). Six patients remained biochemically controlled at the latest follow-up. One patient developed distant metastases after 22 months and one experienced biochemical failure at 30 months with no evidence of distant metastases. No patients experienced acute gastrointestinal toxicities of grade 2 or higher. There were no cases of late gastrointestinal or genitourinary toxicity. High-dose IG-IMRT results in high rates of salvage and extremely low rates of serious late toxicity for patients with locally recurrent prostate cancer after cryotherapy. Although the results are encouraging, given the small number of patients in this and other series, we remain cautious with regard to this treatment and believe the use of salvage radiation therapy after cryotherapy warrants further study.

Current advancement in radiation therapy for uterine cervical cancer.

PubMed

Nakano, Takashi; Ohno, Tatsuya; Ishikawa, Hitoshi; Suzuki, Yoshiyuki; Takahashi, Takeo

2010-01-01

Radiation therapy is one of the effective curative treatments for uterine cervical cancer. However poor clinical results for the advanced stages require further improvement of the treatment. Intensive studies on basic and clinical research have been made to improve local control, primarily important for long term survival in radiation therapy. Regarding current advancement in radiation therapy for uterine cervical cancer, the following three major subjects are pointed out; technological development to improve dose distribution by image guided radiation therapy technology, the concomitant anticancer chemotherapy with combination of radiation therapy, and radiation biological assessment of the radiation resistance of tumors. The biological factors overviewed in this article include hypoxia relating factors of HIF-1alpha, SOD, cell cycle parameters of pMI, proliferation factors of Ki67, EGFR, cerbB2, COX-2, cycle regulation proteins p53, p21, apoptosis regulation proteins Bcl2 and Bax and so on. Especially, the variety of these radiation biological factors is important for the selection of an effective treatment method for each patient to maximize the treatment benefit.

Comparative Prospective Study Reporting Intraoperative Parameters, Pedicle Screw Perforation, and Radiation Exposure in Navigation-Guided versus Non-navigated Fluoroscopy-Assisted Minimal Invasive Transforaminal Lumbar Interbody Fusion

PubMed Central

Kundnani, Vishal; Dutta, Shumayou; Patel, Ankit; Mehta, Gaurav; Singh, Mahendra

2018-01-01

Study Design Prospective cohort study. Purpose To compare intraoperative parameters, radiation exposure, and pedicle screw perforation rate in navigation-guided versus non-navigated fluoroscopy-assisted minimal invasive transforaminal lumbar interbody fusion (MIS TLIF). Overview of Literature The poor reliability of fluoroscopy-guided instrumentation and growing concerns about radiation exposure have led to the development of navigation-guided instrumentation techniques in MIS TLIF. The literature evaluating the efficacy of navigation-guided MIS TLIF is scant. Methods Eighty-seven patients underwent navigation- or fluoroscopy-guided MIS TLIF for symptomatic lumbar/lumbosacral spondylolisthesis. Demographics, intraoperative parameters (surgical time, blood loss), and radiation exposure (sec/mGy/Gy.cm2 noted from C-arm for comparison only) were recorded. Computed tomography was performed in patients in the navigation and non-navigation groups at postoperative 12 months and reviewed by an independent observer to assess the accuracy of screw placement, perforation incidence, location, grade (Mirza), and critical versus non-critical neurological implications. Results Twenty-seven patients (male/female, 11/16; L4–L5/L5–S1, 9/18) were operated with navigation-guided MIS TLIF, whereas 60 (male/female, 25/35; L4–L5/L5–S1, 26/34) with conventional fluoroscopy-guided MIS TILF. The use of navigation resulted in reduced fluoroscopy usage (dose area product, 0.47 Gy.cm2 versus 2.93 Gy.cm2), radiation exposure (1.68 mGy versus 10.97 mGy), and fluoroscopy time (46.5 seconds versus 119.08 seconds), with p-values of <0.001. Furthermore, 96.29% (104/108) of pedicle screws in the navigation group were accurately placed (grade 0) (4 breaches, all grade I) compared with 91.67% (220/240) in the non-navigation group (20 breaches, 16 grade I+4 grade II; p=0.114). None of the breaches resulted in a corresponding neurological deficit or required revision. Conclusions Navigation guidance in MIS TLIF reduced radiation exposure, but the perforation status was not statistically different than that for the fluoroscopy-based technique. Thus, navigation in nondeformity cases is useful for significantly reducing the radiation exposure, but its ability to reduce pedicle screw perforation in nondeformity cases remains to be proven. PMID:29713413

Complications in CT-guided procedures: do we really need postinterventional CT control scans?

PubMed

Nattenmüller, Johanna; Filsinger, Matthias; Bryant, Mark; Stiller, Wolfram; Radeleff, Boris; Grenacher, Lars; Kauczor, Hans-Ullrich; Hosch, Waldemar

2014-02-01

The aim of this study is twofold: to determine the complication rate in computed tomography (CT)-guided biopsies and drainages, and to evaluate the value of postinterventional CT control scans. Retrospective analysis of 1,067 CT-guided diagnostic biopsies (n = 476) and therapeutic drainages (n = 591) in thoracic (n = 37), abdominal (n = 866), and musculoskeletal (ms) (n = 164) locations. Severity of any complication was categorized as minor or major. To assess the need for postinterventional CT control scans, it was determined whether complications were detected clinically, on peri-procedural scans or on postinterventional scans only. The complication rate was 2.5 % in all procedures (n = 27), 4.4 % in diagnostic punctures, and 1.0 % in drainages; 13.5 % in thoracic, 2.0 % in abdominal, and 3.0 % in musculoskeletal procedures. There was only 1 major complication (0.1 %). Pneumothorax (n = 14) was most frequent, followed by bleeding (n = 9), paresthesia (n = 2), material damage (n = 1), and bone fissure (n = 1). Postinterventional control acquisitions were performed in 65.7 % (701 of 1,067). Six complications were solely detectable in postinterventional control acquisitions (3 retroperitoneal bleeds, 3 pneumothoraces); all other complications were clinically detectable (n = 4) and/or visible in peri-interventional controls (n = 21). Complications in CT-guided interventions are rare. Of these, thoracic interventions had the highest rate, while pneumothoraces and bleeding were most frequent. Most complications can be detected clinically or peri-interventionally. To reduce the radiation dose, postinterventional CT controls should not be performed routinely and should be restricted to complicated or retroperitoneal interventions only.

The MRI-Linear Accelerator Consortium: Evidence-Based Clinical Introduction of an Innovation in Radiation Oncology Connecting Researchers, Methodology, Data Collection, Quality Assurance, and Technical Development.

PubMed

Kerkmeijer, Linda G W; Fuller, Clifton D; Verkooijen, Helena M; Verheij, Marcel; Choudhury, Ananya; Harrington, Kevin J; Schultz, Chris; Sahgal, Arjun; Frank, Steven J; Goldwein, Joel; Brown, Kevin J; Minsky, Bruce D; van Vulpen, Marco

2016-01-01

An international research consortium has been formed to facilitate evidence-based introduction of MR-guided radiotherapy (MR-linac) and to address how the MR-linac could be used to achieve an optimized radiation treatment approach to improve patients' survival, local, and regional tumor control and quality of life. The present paper describes the organizational structure of the clinical part of the MR-linac consortium. Furthermore, it elucidates why collaboration on this large project is necessary, and how a central data registry program will be implemented.

78 FR 64030 - Monitoring Criteria and Methods To Calculate Occupational Radiation Doses

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-25

... NUCLEAR REGULATORY COMMISSION [NRC-2013-0234] Monitoring Criteria and Methods To Calculate... regulatory guide (DG), DG-8031, ``Monitoring Criteria and Methods to Calculate Occupational Radiation Doses.'' This guide describes methods that the NRC staff considers acceptable for licensees to use to determine...

Radiated Emissions from a Remote-Controlled Airplane-Measured in a Reverberation Chamber

NASA Technical Reports Server (NTRS)

Ely, Jay J.; Koppen, Sandra V.; Nguyen, Truong X.; Dudley, Kenneth L.; Szatkowski, George N.; Quach, Cuong C.; Vazquez, Sixto L.; Mielnik, John J.; Hogge, Edward F.; Hill, Boyd L.;

An Intelligent Catheter System Robotic Controlled Catheter System

PubMed Central

Negoro, M.; Tanimoto, M.; Arai, F.; Fukuda, T.; Fukasaku, K.; Takahashi, I.; Miyachi, S.

2001-01-01

Summary We have developed a novel catheter system, an intelligent catheter system, which is able to control a catheter by an externally-placed controller. This system has made from master-slave mechanism and has following three components; 1) a joy stick as a master (for operators) 2)a catheter controller as a slave (for a patient),3)a micro force sensor as a sensing device. This catheter tele-guiding system has abilities to perform intravascular procedures from the distant places. It may help to reduce the radiation exposures to the operators and also to help train young doctors. PMID:20663387

New technologies in radiation therapy: ensuring patient safety, radiation safety and regulatory issues in radiation oncology.

PubMed

Amols, Howard I

2008-11-01

New technologies such as intensity modulated and image guided radiation therapy, computer controlled linear accelerators, record and verify systems, electronic charts, and digital imaging have revolutionized radiation therapy over the past 10-15 y. Quality assurance (QA) as historically practiced and as recommended in reports such as American Association of Physicists in Medicine Task Groups 40 and 53 needs to be updated to address the increasing complexity and computerization of radiotherapy equipment, and the increased quantity of data defining a treatment plan and treatment delivery. While new technology has reduced the probability of many types of medical events, seeing new types of errors caused by improper use of new technology, communication failures between computers, corrupted or erroneous computer data files, and "software bugs" are now being seen. The increased use of computed tomography, magnetic resonance, and positron emission tomography imaging has become routine for many types of radiotherapy treatment planning, and QA for imaging modalities is beyond the expertise of most radiotherapy physicists. Errors in radiotherapy rarely result solely from hardware failures. More commonly they are a combination of computer and human errors. The increased use of radiosurgery, hypofractionation, more complex intensity modulated treatment plans, image guided radiation therapy, and increasing financial pressures to treat more patients in less time will continue to fuel this reliance on high technology and complex computer software. Clinical practitioners and regulatory agencies are beginning to realize that QA for new technologies is a major challenge and poses dangers different in nature than what are historically familiar.

Broad band waveguide spectrometer

DOEpatents

Goldman, Don S.

1995-01-01

A spectrometer for analyzing a sample of material utilizing a broad band source of electromagnetic radiation and a detector. The spectrometer employs a waveguide possessing an entry and an exit for the electromagnetic radiation emanating from the source. The waveguide further includes a surface between the entry and exit portions which permits interaction between the electromagnetic radiation passing through the wave guide and a sample material. A tapered portion forms a part of the entry of the wave guide and couples the electromagnetic radiation emanating from the source to the waveguide. The electromagnetic radiation passing from the exit of the waveguide is captured and directed to a detector for analysis.

Formerly Utilized Sites Remedial Action Program (FUSRAP) Hazelwood Interim Storage Site annual site environmental report. Calendar year 1985. [FUSRAP

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-04-01

The Hazelwood Interim Storage Site (HISS) is presently used for the storage of low-level radioactively contaminated soils. Monitoring results show that the HISS is in compliance with DOE concentration guides and radiation protection standards. Derived Concentration Guides (DCGs) represent the concentrations of radionuclides in air or water that would limit the radiation dose to 100 mrem/y. The applicable limits have been revised since the 1984 environmental monitoring report was published. The limits applied in 1984 were based on a radiation protection standard of 500 mrem/y; the limits applied for 1985 are based on a standard of 100 mrem/y. The HISSmore » is part of the Formerly Utilized Sites Remedial Action Program (FUSRAP), a DOE program to decontaminate or otherwise control sites where low-level radioactive contamination remains from the early years of the nation's atomic energy program. To determine whether the site is in compliance with DOE standards, environmental measurements are expressed as percentages of the applicable DCG, while the calculated doses to the public are expressed as percentages of the applicable radiation protection standard. The monitoring program at the HISS measures uranium, radium, and thorium concentrations in surface water, groundwater, and sediment; radon gas concentrations in air; and external gamma radiation exposure rates. Potential radiation doses to the public are also calculated. The HISS was designated for remedial action under FUSRAP because radioactivity above applicable limits was found to exist at the site and its vicinity. Elevated levels of radiation still exist in areas where remedial action has not yet been completed.« less

Accumulated Delivered Dose Response of Stereotactic Body Radiation Therapy for Liver Metastases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swaminath, Anand; Massey, Christine; Brierley, James D.

2015-11-01

Purpose: To determine whether the accumulated dose using image guided radiation therapy is a stronger predictor of clinical outcomes than the planned dose in stereotactic body radiation therapy (SBRT) for liver metastases. Methods and Materials: From 2003 to 2009, 81 patients with 142 metastases were treated in institutional review board–approved SBRT studies (5-10 fractions). Patients were treated during free breathing (with or without abdominal compression) or with controlled exhale breath-holding. SBRT was planned on a static exhale computed tomography (CT) scan, and the minimum planning target volume dose to 0.5 cm{sup 3} (minPTV) was recorded. The accumulated minimum dose to themore » 0.5 cm{sup 3} gross tumor volume (accGTV) was calculated after performing dose accumulation from exported image guided radiation therapy data sets registered to the planning CT using rigid (2-dimensional MV/kV orthogonal) or deformable (3-dimensional/4-dimensional cone beam CT) image registration. Univariate and multivariate Cox regression models assessed the factors influencing the time to local progression (TTLP). Hazard ratios for accGTV and minPTV were compared using model goodness-of-fit and bootstrapping. Results: Overall, the accGTV dose exceeded the minPTV dose in 98% of the lesions. For 5 to 6 fractions, accGTV doses of >45 Gy were associated with 1-year local control of 86%. On univariate analysis, the cancer subtype (breast), smaller tumor volume, and increased dose were significant predictors for improved TTLP. The dose and volume were uncorrelated; the accGTV dose and minPTV dose were correlated and were tested separately on multivariate models. Breast cancer subtype, accGTV dose (P<.001), and minPTV dose (P=.02) retained significance in the multivariate models. The univariate hazard ratio for TTLP for 5-Gy increases in accGTV versus minPTV was 0.67 versus 0.74 (all patients; 95% confidence interval of difference 0.03-0.14). Goodness-of-fit testing confirmed the accGTV dose as a stronger dose–response predictor than the minPTV dose. Conclusions: The accGTV dose is a better predictor of TTLP than the minPTV dose for liver metastasis SBRT. The use of modern image guided radiation therapy in future analyses of dose–response outcomes should increase the concordance between the planned and delivered doses.« less

Using the IRPA Guiding Principles on Stakeholder Engagement: putting theory into practice.

PubMed

Jones, C Rick

2011-11-01

The International Radiation Protection Association (IRPA) published their Guiding Principles for Radiation Protection Professionals on Stakeholder Engagement in February 2009. The publication of this document is the culmination of four years of work by the Spanish Society for Radiological Protection, the French Society of Radioprotection, the United Kingdom Society of Radiological Protection, and the IRPA organization, with full participation by the Italian Associate Society and the Nuclear Energy Agency's Committee on Radiation Protection and Public Health. The Guiding Principles provide field-tested and sound counsel to the radiation protection profession to aid it in successfully engaging with stakeholders in decision-making processes that result in mutually agreeable and sustainable decisions. Stakeholders in the radiation protection decision making process are now being recognized as a spectrum of individuals and organizations specific to the situation. It is also important to note that stakeholder engagement is not needed or advised in all decision making situations, although it has been shown to be a tool of first choice in dealing with such topics as intervention and chronic exposure situations, as well as situations that have reached an impasse using traditional approaches to decision-making. To enhance the contribution of the radiation protection profession, it is important for radiation protection professionals and their national professional societies to embrace and implement the IRPA Guiding Principles in a sustainable way by making them a cornerstone of their operations and an integral part of day-to-day activities.

St. Louis Airport Site annual site environmental report. Calendar year 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-04-01

During 1985, the environmental monitoring program was continued at the St. Louis Airport Site (SLAPS) in St. Louis County, Missouri. The ditches north and south of the site have been designated for cleanup as part of the Formerly Utilized Sites Remedial Action Program (FUSRAP), a United States Department of Energy (DOE) program to identify, decontaminate, or otherwise control sites where low-level radioactive contamination remains from the early years of the nation's atomic energy program. The site is not currently controlled or regulated by DOE or NRC, although radiological monitoring of the site has been authorized by the DOE. The monitoringmore » program at the SLAPS measures radon gas concentrations in air; external gamma radiation dose rates; and uranium, thorium, and radium concentrations in surface water, groundwater, and sediment. Potential radiation doses to the public are also calculated. Because the site is not controlled or regulated by the DOE, the DOE Derived Concentration Guides (DCGs) are not applicable to SLAPS, but are included as a basis for comparison only. The DOE DCGs and the DOE radiation protection standard have been revised.« less

Recent Advances in Image-Guided Radiotherapy for Head and Neck Carcinoma

PubMed Central

Nath, Sameer K.; Simpson, Daniel R.; Rose, Brent S.; Sandhu, Ajay P.

2009-01-01

Radiotherapy has a well-established role in the management of head and neck cancers. Over the past decade, a variety of new imaging modalities have been incorporated into the radiotherapy planning and delivery process. These technologies are collectively referred to as image-guided radiotherapy and may lead to significant gains in tumor control and radiation side effect profiles. In the following review, these techniques as they are applied to head and neck cancer patients are described, and clinical studies analyzing their use in target delineation, patient positioning, and adaptive radiotherapy are highlighted. Finally, we conclude with a brief discussion of potential areas of further radiotherapy advancement. PMID:19644564

Spatio-temporal control of gene expression and cancer treatment using magnetic resonance imaging-guided focused ultrasound.

PubMed

Moonen, Chrit T W

2007-06-15

Local temperature elevation may be used for tumor ablation, gene expression, drug activation, and gene and/or drug delivery. High-intensity focused ultrasound (HIFU) is the only clinically viable technology that can be used to achieve a local temperature increase deep inside the human body in a noninvasive way. Magnetic resonance imaging (MRI) guidance of the procedure allows in situ target definition and identification of nearby healthy tissue to be spared. In addition, MRI can be used to provide continuous temperature mapping during HIFU for spatial and temporal control of the heating procedure and prediction of the final lesion based on the received thermal dose. The primary purpose of the development of MRI-guided HIFU was to achieve safe noninvasive tissue ablation. The technique has been tested extensively in preclinical studies and is now accepted in the clinic for ablation of uterine fibroids. MRI-guided HIFU for ablation shows conceptual similarities with radiation therapy. However, thermal damage generally shows threshold-like behavior, with necrosis above the critical thermal dose and full recovery below. MRI-guided HIFU is being clinically evaluated in the cancer field. The technology also shows great promise for a variety of advanced therapeutic methods, such as gene therapy. MR-guided HIFU, together with the use of a temperature-sensitive promoter, provides local, physical, and spatio-temporal control of transgene expression. Specially designed contrast agents, together with the combined use of MRI and ultrasound, may be used for local gene and drug delivery.

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2014 CFR

2014-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

29 CFR 1910.97 - Nonionizing radiation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... radiation. (a) Electromagnetic radiation—(1) Definitions applicable to this paragraph. (i) The term electromagnetic radiation is restricted to that portion of the spectrum commonly defined as the radio frequency... electromagnetic energy. (iii) Radiation protection guide. Radiation level which should not be exceeded without...

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ryan, E. Ronan, E-mail: ronan@ronanryan.com; Thornton, Raymond; Sofocleous, Constantinos T.

PurposeTo quantify radiation exposure to the primary operator and staff during PET/CT-guided interventional procedures.MethodsIn this prospective study, 12 patients underwent PET/CT-guided interventions over a 6 month period. Radiation exposure was measured for the primary operator, the radiology technologist, and the nurse anesthetist by means of optically stimulated luminescence dosimeters. Radiation exposure was correlated with the procedure time and the use of in-room image guidance (CT fluoroscopy or ultrasound).ResultsThe median effective dose was 0.02 (range 0-0.13) mSv for the primary operator, 0.01 (range 0-0.05) mSv for the nurse anesthetist, and 0.02 (range 0-0.05) mSv for the radiology technologist. The median extremitymore » dose equivalent for the operator was 0.05 (range 0-0.62) mSv. Radiation exposure correlated with procedure duration and with the use of in-room image guidance. The median operator effective dose for the procedure was 0.015 mSv when conventional biopsy mode CT was used, compared to 0.06 mSv for in-room image guidance, although this did not achieve statistical significance as a result of the small sample size (p = 0.06).ConclusionThe operator dose from PET/CT-guided procedures is not significantly different than typical doses from fluoroscopically guided procedures. The major determinant of radiation exposure to the operator from PET/CT-guided interventional procedures is time spent in close proximity to the patient.« less

Bioluminescence Tomography–Guided Radiation Therapy for Preclinical Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Bin; Wang, Ken Kang-Hsin, E-mail: kwang27@jhmi.edu; Yu, Jingjing

Purpose: In preclinical radiation research, it is challenging to localize soft tissue targets based on cone beam computed tomography (CBCT) guidance. As a more effective method to localize soft tissue targets, we developed an online bioluminescence tomography (BLT) system for small-animal radiation research platform (SARRP). We demonstrated BLT-guided radiation therapy and validated targeting accuracy based on a newly developed reconstruction algorithm. Methods and Materials: The BLT system was designed to dock with the SARRP for image acquisition and to be detached before radiation delivery. A 3-mirror system was devised to reflect the bioluminescence emitted from the subject to a stationarymore » charge-coupled device (CCD) camera. Multispectral BLT and the incomplete variables truncated conjugate gradient method with a permissible region shrinking strategy were used as the optimization scheme to reconstruct bioluminescent source distributions. To validate BLT targeting accuracy, a small cylindrical light source with high CBCT contrast was placed in a phantom and also in the abdomen of a mouse carcass. The center of mass (CoM) of the source was recovered from BLT and used to guide radiation delivery. The accuracy of the BLT-guided targeting was validated with films and compared with the CBCT-guided delivery. In vivo experiments were conducted to demonstrate BLT localization capability for various source geometries. Results: Online BLT was able to recover the CoM of the embedded light source with an average accuracy of 1 mm compared to that with CBCT localization. Differences between BLT- and CBCT-guided irradiation shown on the films were consistent with the source localization revealed in the BLT and CBCT images. In vivo results demonstrated that our BLT system could potentially be applied for multiple targets and tumors. Conclusions: The online BLT/CBCT/SARRP system provides an effective solution for soft tissue targeting, particularly for small, nonpalpable, or orthotopic tumor models.« less

Image-guided, intensity-modulated radiation therapy (IG-IMRT) for skull base chordoma and chondrosarcoma: preliminary outcomes.

PubMed

Sahgal, Arjun; Chan, Michael W; Atenafu, Eshetu G; Masson-Cote, Laurence; Bahl, Gaurav; Yu, Eugene; Millar, Barbara-Ann; Chung, Caroline; Catton, Charles; O'Sullivan, Brian; Irish, Jonathan C; Gilbert, Ralph; Zadeh, Gelareh; Cusimano, Michael; Gentili, Fred; Laperriere, Normand J

2015-06-01

We report our preliminary outcomes following high-dose image-guided intensity modulated radiotherapy (IG-IMRT) for skull base chordoma and chondrosarcoma. Forty-two consecutive IG-IMRT patients, with either skull base chordoma (n = 24) or chondrosarcoma (n = 18) treated between August 2001 and December 2012 were reviewed. The median follow-up was 36 months (range, 3-90 mo) in the chordoma cohort, and 67 months (range, 15-125) in the chondrosarcoma cohort. Initial surgery included biopsy (7% of patients), subtotal resection (57% of patients), and gross total resection (36% of patients). The median IG-IMRT total doses in the chondrosarcoma and chordoma cohorts were 70 Gy and 76 Gy, respectively, delivered with 2 Gy/fraction. For the chordoma and chondrosarcoma cohorts, the 5-year overall survival and local control rates were 85.6% and 65.3%, and 87.8% and 88.1%, respectively. In total, 10 patients progressed locally: 8 were chordoma patients and 2 chondrosarcoma patients. Both chondrosarcoma failures were in higher-grade tumors (grades 2 and 3). None of the 8 patients with grade 1 chondrosarcoma failed, with a median follow-up of 77 months (range, 34-125). There were 8 radiation-induced late effects-the most significant was a radiation-induced secondary malignancy occurring 6.7 years following IG-IMRT. Gross total resection and age were predictors of local control in the chordoma and chondrosarcoma patients, respectively. We report favorable survival, local control and adverse event rates following high dose IG-IMRT. Further follow-up is needed to confirm long-term efficacy. © The Author(s) 2014. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Poster - Thurs Eve-16: Just-in-time tomography (JiTT).

PubMed

Pang, G; Rowlands, J A

2008-07-01

Soft-tissue target motion is one of the main concerns in high-precision radiation therapy. Cone beam computed tomography (CBCT) has been developed recently to image soft-tissue targets in the treatment room for image-guided radiation therapy. However, due to its relatively long image acquisition time the CBCT approach cannot provide images of the target at the instant of the treatment and thus is not adequate for imaging targets with intrafraction motion. In this work, a new concept for image-guided radiation therapy- just-in-time tomography (JiTT) - is introduced. Differing from CBCT, JiTT takes much less time to generate the needed tomographical, beam's-eye-view images of the treatment target at the right moment to guide the radiation therapy treatment. A system to achieve JiTT is proposed and its feasibility is investigated. Research supported by Siemens. © 2008 American Association of Physicists in Medicine.

Electron wind in strong wave guide fields

NASA Astrophysics Data System (ADS)

Krienen, F.

1985-03-01

The X-ray activity observed near highly powered waveguide structures is usually caused by local electric discharges originating from discontinuities such as couplers, tuners or bends. In traveling waves electrons move in the direction of the power flow. Seed electrons can multipactor in a traveling wave, the moving charge pattern is different from the multipactor in a resonant structure and is self-extinguishing. The charge density in the wave guide will modify impedance and propagation constant of the wave guide. The radiation level inside the output wave guide of the SLAC, 50 MW, S-band, klystron is estimated. Possible contributions of radiation to window failure are discussed.

Effectiveness of electrocardiographic guidance in CVAD tip placement.

PubMed

Walker, Graham; Chan, Raymond J; Alexandrou, Evan; Webster, Joan; Rickard, Claire

International standard practice for the correct confirmation of the central venous access device is the chest X-ray. The intracavitary electrocardiogram-based insertion method is radiation-free, and allows real-time placement verification, providing immediate treatment and reduced requirement for post-procedural repositioning. Relevant databases were searched for prospective randomised controlled trials (RCTs) or quasi RCTs that compared the effectiveness of electrocardiogram-guided catheter tip positioning with placement using surface-anatomy-guided insertion plus chest X-ray confirmation. The primary outcome was accurate catheter tip placement. Secondary outcomes included complications, patient satisfaction and costs. Five studies involving 729 participants were included. Electrocardiogram-guided insertion was more accurate than surface anatomy guided insertion (odds ratio: 8.3; 95% confidence interval (CI) 1.38; 50.07; p=0.02). There was a lack of reporting on complications, patient satisfaction and costs. The evidence suggests that intracavitary electrocardiogram-based positioning is superior to surface-anatomy-guided positioning of central venous access devices, leading to significantly more successful placements. This technique could potentially remove the requirement for post-procedural chest X-ray, especially during peripherally inserted central catheter (PICC) line insertion.

Optical Verification of Microbubble Response to Acoustic Radiation Force in Large Vessels With In Vivo Results.

PubMed

Wang, Shiying; Wang, Claudia Y; Unnikrishnan, Sunil; Klibanov, Alexander L; Hossack, John A; Mauldin, F William

2015-11-01

The objective of this study was to optically verify the dynamic behaviors of adherent microbubbles in large blood vessel environments in response to a new ultrasound technique using modulated acoustic radiation force. Polydimethylsiloxane (PDMS) flow channels coated with streptavidin were used in targeted groups to mimic large blood vessels. The custom-modulated acoustic radiation force beam sequence was programmed on a Verasonics research scanner. In vitro experiments were performed by injecting a biotinylated lipid-perfluorobutane microbubble dispersion through flow channels. The dynamic response of adherent microbubbles was detected acoustically and simultaneously visualized using a video camera connected to a microscope. In vivo verification was performed in a large abdominal blood vessel of a murine model for inflammation with injection of biotinylated microbubbles conjugated with P-selectin antibody. Aggregates of adherent microbubbles were observed optically under the influence of acoustic radiation force. Large microbubble aggregates were observed solely in control groups without targeted adhesion. Additionally, the dispersion of microbubble aggregates were demonstrated to lead to a transient acoustic signal enhancement in control groups (a new phenomenon we refer to as "control peak"). In agreement with in vitro results, the control peak phenomenon was observed in vivo in a murine model. This study provides the first optical observation of microbubble-binding dynamics in large blood vessel environments with application of a modulated acoustic radiation force beam sequence. With targeted adhesion, secondary radiation forces were unable to produce large aggregates of adherent microbubbles. Additionally, the new phenomenon called control peak was observed both in vitro and in vivo in a murine model for the first time. The findings in this study provide us with a better understanding of microbubble behaviors in large blood vessel environments with application of acoustic radiation force and could potentially guide future beam sequence designs or signal processing routines for enhanced ultrasound molecular imaging.

Optical Verification of Microbubble Response to Acoustic Radiation Force in Large Vessels with In Vivo Results

PubMed Central

Wang, Shiying; Wang, Claudia Y.; Unnikrishnan, Sunil; Klibanov, Alexander L.; Hossack, John A.; Mauldin, F. William

2015-01-01

Objectives To optically verify the dynamic behaviors of adherent microbubbles in large blood vessel environments in response to a new ultrasound technique using modulated acoustic radiation force. Materials and Methods Polydimethylsiloxane (PDMS) flow channels coated with streptavidin were used in targeted groups to mimic large blood vessels. The custom modulated acoustic radiation force beam sequence was programmed on a Verasonics research scanner. In vitro experiments were performed by injecting a biotinylated lipid-perfluorobutane microbubble dispersion through flow channels. The dynamic response of adherent microbubbles was detected acoustically and simultaneously visualized using a video camera connected to a microscope. In vivo verification was performed in a large abdominal blood vessel of a murine model for inflammation with injection of biotinylated microbubbles conjugated with P-selectin antibody. Results Aggregates of adherent microbubbles were observed optically under the influence of acoustic radiation force. Large microbubble aggregates were observed solely in control groups without targeted adhesion. Additionally, the dispersion of microbubble aggregates were demonstrated to lead to a transient acoustic signal enhancement in control groups (a new phenomenon we refer to as “control peak”). In agreement with in vitro results, the “control peak” phenomenon was observed in vivo in a murine model. Conclusions This study provides the first optical observation of microbubble binding dynamics in large blood vessel environments with application of a modulated acoustic radiation force beam sequence. With targeted adhesion, secondary radiation forces were unable to produce large aggregates of adherent microbubbles. Additionally, the new phenomenon called “control peak” was observed both in vitro and in vivo in a murine model for the first time. The findings in this study provide us with a better understanding of microbubble behaviors in large blood vessel environments with application of acoustic radiation force, and could potentially guide future beam sequence designs or signal processing routines for enhanced ultrasound molecular imaging. PMID:26135018

CT Guided Bone Biopsy Using a Battery Powered Intraosseous Device

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schnapauff, Dirk, E-mail: dirk.schnapauff@charite.de; Marnitz, Tim, E-mail: tim.marnitz@charite.de; Freyhardt, Patrick, E-mail: Patrick.freyhardt@charite.de

2013-10-15

Purpose: To evaluate the feasibility of a battery powered intraosseous device to perform CT-fluoroscopy guided bone biopsy. Methods: Retrospective analysis of 12 patients in whom bone specimen were acquired from different locations under CT-fluoroscopy guidance using the OnControl bone marrow biopsy system (OBM, Vidacare, Shavano Park, TX, USA). Data of the 12 were compared to a historic cohort in whom the specimen were acquired using the classic Jamshidi Needle, as reference needle using manual force for biopsy. Results: Technical success was reached in 11 of 12 cases, indicated by central localisation of the needle within the target lesion. All specimenmore » sampled were sufficient for histopathological workup. Compared to the historical cohort the time needed for biopsy decreased significantly from 13 {+-} 6 to 6 {+-} 4 min (P = 0.0001). Due to the shortened intervention time the radiation dose (CTDI) during CT-fluoroscopy was lowered significantly from 169 {+-} 87 to 111 {+-} 54 mGy Multiplication-Sign cm (P = 0.0001). Interventional radiologists were confident with the performance of the needle especially when using in sclerotic or osteoblastic lesions. Conclusion: The OBM is an attractive support for CT-fluoroscopy guided bone biopsy which is safe tool and compared to the classical approach using the Jamshidi needle leading to significantly reduced intervention time and radiation exposure.« less

Radiation exposure of the radiologist's eye lens during CT-guided interventions.

PubMed

Heusch, Philipp; Kröpil, Patric; Buchbender, Christian; Aissa, Joel; Lanzman, Rotem S; Heusner, Till A; Ewen, Klaus; Antoch, Gerald; Fürst, Günther

2014-02-01

In the past decade the number of computed tomography (CT)-guided procedures performed by interventional radiologists have increased, leading to a significantly higher radiation exposure of the interventionalist's eye lens. Because of growing concern that there is a stochastic effect for the development of lens opacification, eye lens dose reduction for operators and patients should be of maximal interest. To determine the interventionalist's equivalent eye lens dose during CT-guided interventions and to relate the results to the maximum of the recommended equivalent dose limit. During 89 CT-guided interventions (e.g. biopsies, drainage procedures, etc.) measurements of eye lens' radiation doses were obtained from a dedicated dosimeter system for scattered radiation. The sensor of the personal dosimeter system was clipped onto the side of the lead glasses which was located nearest to the CT gantry. After the procedure, radiation dose (µSv), dose rate (µSv/min) and the total exposure time (s) were recorded. For all 89 interventions, the median total exposure lens dose was 3.3 µSv (range, 0.03-218.9 µSv) for a median exposure time of 26.2 s (range, 1.1-94.0 s). The median dose rate was 13.9 µSv/min (range, 1.1-335.5 µSv/min). Estimating 50-200 CT-guided interventions per year performed by one interventionalist, the median dose of the eye lens of the interventional radiologist does not exceed the maximum of the ICRP-recommended equivalent eye lens dose limit of 20 mSv per year.

Minimizing radiation exposure during percutaneous nephrolithotomy.

PubMed

Chen, T T; Preminger, G M; Lipkin, M E

2015-12-01

Given the recent trends in growing per capita radiation dose from medical sources, there have been increasing concerns over patient radiation exposure. Patients with kidney stones undergoing percutaneous nephrolithotomy (PNL) are at particular risk for high radiation exposure. There exist several risk factors for increased radiation exposure during PNL which include high Body Mass Index, multiple access tracts, and increased stone burden. We herein review recent trends in radiation exposure, radiation exposure during PNL to both patients and urologists, and various approaches to reduce radiation exposure. We discuss incorporating the principles of As Low As reasonably Achievable (ALARA) into clinical practice and review imaging techniques such as ultrasound and air contrast to guide PNL access. Alternative surgical techniques and approaches to reducing radiation exposure, including retrograde intra-renal surgery, retrograde nephrostomy, endoscopic-guided PNL, and minimally invasive PNL, are also highlighted. It is important for urologists to be aware of these concepts and techniques when treating stone patients with PNL. The discussions outlined will assist urologists in providing patient counseling and high quality of care.

Laboratory Services Guide

DTIC Science & Technology

1994-10-01

dosimetry services using thermoluminescent dosimeters ( TLDs ) to meet 10 CFR 19, 20, 30-36, 40 and 70; to proNide dosimetry service for environmental...USAF Personnel Dosimetry Branch. Once it is determined that area or external dosimetry is necessary, request the number of TLDs required by FAX or letter... dosimetry , Request TLDs 2 - 4 weeks in advance and always designate a control badge. The Radiation Dosimetry Branch thanks you in advance for doing everything

Laser-assisted guiding of electric discharges around objects

PubMed Central

Clerici, Matteo; Hu, Yi; Lassonde, Philippe; Milián, Carles; Couairon, Arnaud; Christodoulides, Demetrios N.; Chen, Zhigang; Razzari, Luca; Vidal, François; Légaré, François; Faccio, Daniele; Morandotti, Roberto

2015-01-01

Electric breakdown in air occurs for electric fields exceeding 34 kV/cm and results in a large current surge that propagates along unpredictable trajectories. Guiding such currents across specific paths in a controllable manner could allow protection against lightning strikes and high-voltage capacitor discharges. Such capabilities can be used for delivering charge to specific targets, for electronic jamming, or for applications associated with electric welding and machining. We show that judiciously shaped laser radiation can be effectively used to manipulate the discharge along a complex path and to produce electric discharges that unfold along a predefined trajectory. Remarkably, such laser-induced arcing can even circumvent an object that completely occludes the line of sight. PMID:26601188

11C-Choline-Pet Guided Stereotactic Body Radiation Therapy for Lymph Node Metastases in Oligometastatic Prostate Cancer.

PubMed

Franzese, Ciro; Lopci, Egesta; Di Brina, Lucia; D'Agostino, Giuseppe Roberto; Navarria, Pierina; Mancosu, Pietro; Tomatis, Stefano; Chiti, Arturo; Scorsetti, Marta

2017-10-21

aim is outcome of 11C-Choline-PET guided SBRT on lymph node metastases. patients with 1 - 4 lymph node metastases detected by 11C-choline-PET were treated with SBRT. Toxicity, treated metastases control and Progression Free Survival were computed. twenty-six patients, 38 lymph node metastases were irradiated. No grade ≥ 2 toxicity. Median PSA-nadir after RT was 1.02 ng/mL. Post-treatment 11C-Choline-PET showed metabolic complete response in 17 metastases (44,7%), partial response in 9 metastases (38%). SBRT is effective and safe for lymph node metastases. PET is important in identification of gross tumor and evaluation of the response.

75 FR 52996 - Draft Regulatory Guide: Issuance, Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-30

... NUCLEAR REGULATORY COMMISSION [NRC-2010-0287] Draft Regulatory Guide: Issuance, Availability AGENCY: Nuclear Regulatory Commission. ACTION: Notice of issuance and availability of Draft Regulatory Guide, DG-8035, ``Administrative Practices in Radiation Surveys and Monitoring.'' FOR FURTHER...

Science, Society, and America's Nuclear Waste: Ionizing Radiation, Unit 2. Teacher Guide. Second Edition.

ERIC Educational Resources Information Center

Department of Energy, Washington, DC. Office of Civilian Radioactive Waste Management, Washington, DC.

This guide is Unit 2 of the four-part series, Science, Society, and America's Nuclear Waste, produced by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management. The goal of this unit is to convey factual information relevant to radioactivity and radiation and relate that information both to the personal lives of students…

PEACETIME RADIATION HAZARDS IN THE FIRE SERVICE, BASIC COURSE, RESOURCE MANUAL.

ERIC Educational Resources Information Center

BERNDT, WILLIAM

FOR USE BY FIREMEN AND OTHER EMERGENCY PERSONNEL WHO MAY HAVE TO DEAL WITH FIRES OR SIMILAR EMERGENCIES INVOLVING RADIATION HAZARDS, THIS MANUAL IS CORRELATED WITH THE FOLLOWING INSTRUCTIONAL MATERIALS FOR THE 15-HOUR COURSE -- (1) AN INSTRUCTOR'S GUIDE (VT 002 117), (2) A STUDENT STUDY GUIDE (VT 001 878), AND (3) A SET OF TWENTY-TWO 20- BY…

Use of an image-guided robotic radiosurgery system for the treatment of canine nonlymphomatous nasal tumors.

PubMed

Glasser, Seth A; Charney, Sarah; Dervisis, Nikolaos G; Witten, Matthew R; Ettinger, Susan; Berg, Jason; Joseph, Richard

2014-01-01

An image-guided robotic stereotactic radiosurgery (SRS) system can be used to deliver curative-intent radiation in either single fraction or hypofractionated doses. Medical records for 19 dogs with nonlymphomatous nasal tumors treated with hypofractionated image-guided robotic stereotactic body radiotherapy (SBRT), either with or without adjunctive treatment, were retrospectively analyzed for survival and prognostic factors. Median survival time (MST) was evaluated using Kaplan-Meier survival curves. Age, breed, tumor type, stage, tumor size, prescribed radiation dose, and heterogeneity index were analyzed for prognostic significance. Dogs were treated with three consecutive-day, 8-12 gray (Gy) fractions of image-guided robotic SBRT. Overall MST was 399 days. No significant prognostic factors were identified. Acute side effects were rare and mild. Late side effects included one dog with an oronasal fistula and six dogs with seizures. In three of six dogs, seizures were a presenting complaint prior to SBRT. The cause of seizures in the remaining three dogs could not be definitively determined due to lack of follow-up computed tomography (CT) imaging. The seizures could have been related to either progression of disease or late radiation effect. Results indicate that image-guided robotic SBRT, either with or without adjunctive therapy, for canine nonlymphomatous nasal tumors provides comparable survival times (STs) to daily fractionated megavoltage radiation with fewer required fractions and fewer acute side effects.

Development of a novel preclinical pancreatic cancer research model: bioluminescence image-guided focal irradiation and tumor monitoring of orthotopic xenografts.

PubMed

Tuli, Richard; Surmak, Andrew; Reyes, Juvenal; Hacker-Prietz, Amy; Armour, Michael; Leubner, Ashley; Blackford, Amanda; Tryggestad, Erik; Jaffee, Elizabeth M; Wong, John; Deweese, Theodore L; Herman, Joseph M

2012-04-01

We report on a novel preclinical pancreatic cancer research model that uses bioluminescence imaging (BLI)-guided irradiation of orthotopic xenograft tumors, sparing of surrounding normal tissues, and quantitative, noninvasive longitudinal assessment of treatment response. Luciferase-expressing MiaPaCa-2 pancreatic carcinoma cells were orthotopically injected in nude mice. BLI was compared to pathologic tumor volume, and photon emission was assessed over time. BLI was correlated to positron emission tomography (PET)/computed tomography (CT) to estimate tumor dimensions. BLI and cone-beam CT (CBCT) were used to compare tumor centroid location and estimate setup error. BLI and CBCT fusion was performed to guide irradiation of tumors using the small animal radiation research platform (SARRP). DNA damage was assessed by γ-H2Ax staining. BLI was used to longitudinally monitor treatment response. Bioluminescence predicted tumor volume (R = 0.8984) and increased linearly as a function of time up to a 10-fold increase in tumor burden. BLI correlated with PET/CT and necropsy specimen in size (P < .05). Two-dimensional BLI centroid accuracy was 3.5 mm relative to CBCT. BLI-guided irradiated pancreatic tumors stained positively for γ-H2Ax, whereas surrounding normal tissues were spared. Longitudinal assessment of irradiated tumors with BLI revealed significant tumor growth delay of 20 days relative to controls. We have successfully applied the SARRP to a bioluminescent, orthotopic preclinical pancreas cancer model to noninvasively: 1) allow the identification of tumor burden before therapy, 2) facilitate image-guided focal radiation therapy, and 3) allow normalization of tumor burden and longitudinal assessment of treatment response.

Development of a Novel Preclinical Pancreatic Cancer Research Model: Bioluminescence Image-Guided Focal Irradiation and Tumor Monitoring of Orthotopic Xenografts1

PubMed Central

Tuli, Richard; Surmak, Andrew; Reyes, Juvenal; Hacker-Prietz, Amy; Armour, Michael; Leubner, Ashley; Blackford, Amanda; Tryggestad, Erik; Jaffee, Elizabeth M; Wong, John; DeWeese, Theodore L; Herman, Joseph M

2012-01-01

PURPOSE: We report on a novel preclinical pancreatic cancer research model that uses bioluminescence imaging (BLI)-guided irradiation of orthotopic xenograft tumors, sparing of surrounding normal tissues, and quantitative, noninvasive longitudinal assessment of treatment response. MATERIALS AND METHODS: Luciferase-expressing MiaPaCa-2 pancreatic carcinoma cells were orthotopically injected in nude mice. BLI was compared to pathologic tumor volume, and photon emission was assessed over time. BLI was correlated to positron emission tomography (PET)/computed tomography (CT) to estimate tumor dimensions. BLI and cone-beam CT (CBCT) were used to compare tumor centroid location and estimate setup error. BLI and CBCT fusion was performed to guide irradiation of tumors using the small animal radiation research platform (SARRP). DNA damage was assessed by γ-H2Ax staining. BLI was used to longitudinally monitor treatment response. RESULTS: Bioluminescence predicted tumor volume (R = 0.8984) and increased linearly as a function of time up to a 10-fold increase in tumor burden. BLI correlated with PET/CT and necropsy specimen in size (P < .05). Two-dimensional BLI centroid accuracy was 3.5 mm relative to CBCT. BLI-guided irradiated pancreatic tumors stained positively for γ-H2Ax, whereas surrounding normal tissues were spared. Longitudinal assessment of irradiated tumors with BLI revealed significant tumor growth delay of 20 days relative to controls. CONCLUSIONS: We have successfully applied the SARRP to a bioluminescent, orthotopic preclinical pancreas cancer model to noninvasively: 1) allow the identification of tumor burden before therapy, 2) facilitate image-guided focal radiation therapy, and 3) allow normalization of tumor burden and longitudinal assessment of treatment response. PMID:22496923

A patient-mount navigated intervention system for spinal diseases and its clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion.

PubMed

Yang, Chi-Lin; Yang, Been-Der; Lin, Mu-Lien; Wang, Yao-Hung; Wang, Jaw-Lin

2010-10-01

Development of a patient-mount navigated intervention (PaMNI) system for spinal diseases. An in vivo clinical human trial was conducted to validate this system. To verify the feasibility of the PaMNI system with the clinical trial on percutaneous pulsed radiofrequency stimulation of dorsal root ganglion (PRF-DRG). Two major image guiding techniques, i.e., computed tomography (CT)-guided and fluoro-guided, were used for spinal intervention. The CT-guided technique provides high spatial resolution, and is claimed to be more accurate than the fluoro-guided technique. Nevertheless, the CT-guided intervention usually reaches higher radiograph exposure than the fluoro-guided counterpart. Some navigated intervention systems were developed to reduce the radiation of CT-guided intervention. Nevertheless, these systems were not popularly used due to the longer operation time, a new protocol for surgeons, and the availability of such a system. The PaMNI system includes 3 components, i.e., a patient-mount miniature tracking unit, an auto-registered reference frame unit, and a user-friendly image processing unit. The PRF-DRG treatment was conducted to find the clinical feasibility of this system. The in vivo clinical trial showed that the accuracy, visual analog scale evaluation after surgery, and radiograph exposure of the PaMNI-guided technique are comparable to the one of conventional fluoro-guided technique, while the operation time is increased by 5 minutes. Combining the virtues of fluoroscopy and CT-guided techniques, our navigation system is operated like a virtual fluoroscopy with augmented CT images. This system elevates the performance of CT-guided intervention and reduces surgeons' radiation exposure risk to a minimum, while keeping low radiation dose to patients like its fluoro-guided counterpart. The clinical trial of PRF-DRG treatment showed the clinical feasibility and efficacy of this system.

Comparative Effectiveness of Frame-based, Frameless and Intraoperative MRI Guided Brain Biopsy Techniques

PubMed Central

Lu, Yi; Yeung, Cecil; Radmanesh, Alireza; Wiemann, Robert; Black, Peter M.; Golby, Alexandra J.

2015-01-01

Objective Intraoperative MRI (IoMRI) guided brain biopsy provides a real time visual feedback of the lesion that is sampled during surgery. The objective of the study is to compare the diagnostic yield and safety profiles of ioMRI needle brain biopsy with two traditional brain biopsy methods: frame-based and frameless stereotactic brain biopsies. Methods A retrospective analysis from 288 consecutive needle brain biopsies in 277 patients undergoing stereotactic brain biopsy with any of the three biopsy methods at Brigham and Women's Hospital from 2000 to 2008 was performed. Variables such as age, sex, history of radiation and previous surgery, pathology results, complications and postoperative stays were analyzed. Results Over the course of eight years, 288 brain biopsies were performed. 253 (87.8%) biopsies yielded positive diagnostic tissue. Young age (<40 years), history of brain radiation or surgery were significant negative predictors for a positive biopsy diagnostic yield. Excluding patients with prior radiation or surgeries, no significant difference in diagnostic yield was detected among the three groups, with frame-based, frameless and ioMRI guided needle biopsies yield 96.9%, 91.8% and 89.9% positive diagnostic yield, respectively. 19 biopsies (6.6%) were complicated by serious adverse events. The ioMRI-guided brain biopsy was associated with less serious adverse events and the shortest postoperative hospital stay. Conclusions Frame-based, frameless stereotactic and ioMRI guided brain needle biopsy have comparable diagnostic yield for patients with no prior treatments (either radiation or surgery). IoMRI guided brain biopsy is associated with fewer serious adverse events and shorter hospital stay. PMID:25088233

EPRI Guide to Managing Nuclear Utility Protective Clothing Programs. PCEVAL User`s Manual, A computer code for evaluating the economics of nuclear plant protective clothing programs: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, J.J.; Kelly, D.M.

1993-10-01

The Electric Power Research Institute (EPRI) commissioned a radioactive waste related project (RP2414-34) in 1989 to produce a guide for developing and managing nuclear plant protective clothing programs. Every nuclear facility must coordinate some type of protective clothing program for its radiation workers to ensure proper and safe protection for the wearer and to maintain control over the spread of contamination. Yet, every nuclear facility has developed its own unique program for managing such clothing. Accordingly, a need existed for a reference guide to assist with standardizing protective clothing programs and in controlling the potentially escalating economics of such programs.more » The initial Guide to Managing Nuclear Utility Protective Clothing Programs, NP-7309, was published in May 1991. Since that time, a number of utilities have reviewed and/or used the report to enhance their protective clothing programs. Some of these utilities requested that a computer program be developed to assist utilities in evaluating the economics of protective clothing programs consistent with the guidance in NP-7309. The PCEVAL computer code responds to that industry need. This report, the PCEVAL User`s Manual, provides detailed instruction on use of the software.« less

Feasibility of virtual 3-Fr percutaneous coronary intervention using standard guiding catheters

PubMed Central

Fujimoto, Kazuteru; Miyao, Yuji

2014-01-01

Introduction Recent studies have reported the efficacy of sheathless percutaneous coronary intervention (PCI) using hydrophilic-coated 5-Fr guiding catheters that are one to two Fr sizes smaller in diameter than the corresponding introducer sheath (virtual 3-Fr PCI). However, the limited number of shapes of hydrophilic-coated guiding catheters occasionally makes them difficult to engage and control. Aim To evaluate the efficacy and feasibility of virtual 3-Fr PCI using standard guiding catheters of various shapes. Material and methods We identified 35 consecutive patients with stable angina, who underwent virtual 3-Fr PCI using either hydrophilic-coated guiding catheters (Works™, Medikit, Japan) or standard guiding catheters (Heartrail™, Terumo, Japan). Results Thirty-five patients were identified (63% men; mean age 70 ±13 years). In 2 cases, hydrophilic-coated guiding catheters were exchanged to standard guiding catheters because of difficulty in engaging the target coronary arteries. Ultimately, standard guiding catheters were used in 20 patients (57%) and hydrophilic-coated catheters were used in 15 (43%). One of 20 patients treated with standard guiding catheters and 1 of 15 treated with hydrophilic-coated guiding catheters underwent the 4-in-3 “slender mother and child” PCI technique due to difficulty of stent deployment. There were no differences between the two groups in PCI procedural variables such as procedural time, fluoroscopy time, radiation dose, or contrast dye volume. There were no access site-related complications in this study. Conclusions These findings indicate that virtual 3-Fr PCI using standard guiding catheters is as efficient and safe as virtual 3-Fr PCI using hydrophilic-coated guiding catheters. PMID:25489315

Clinical outcomes of image guided radiation therapy (IGRT) with gold fiducial vaginal cuff markers for high-risk endometrial cancer.

PubMed

Monroe, Alan T; Pikaart, Dirk; Peddada, Anuj V

2013-06-01

To report two year clinical outcomes of image guided radiation therapy (IGRT) to the vaginal cuff and pelvic lymph nodes in a series of high-risk endometrial cancer patients. Twenty-six consecutive high-risk endometrial cancer patients requiring adjuvant radiation to the vaginal cuff and regional lymph nodes were treated with vaginal cuff fiducial-based IGRT. Seventeen (65%) received sequential chemotherapy, most commonly with a sandwich technique. Brachytherapy followed external radiation in 11 patients to a median dose of 18 Gy in 3 fractions. The median external beam dose delivered was 47.5 Gy in 25 fractions. All 656 fractions were successfully imaged and treated. The median overall translational shift required for correction was 9.1 mm (standard deviation, 5.2 mm) relative to clinical set-up with skin tattoos. Shifts of 1 cm, 1.5 cm, and 2 cm or greater were performed in 43%, 14%, and 4% of patients, respectively. Acute grade 2 gastrointestinal (GI) toxicity occurred in eight patients (30%) and grade 3 toxicity occurred in one. At two years, there have been no local or regional failures and actuarial overall survival is 95%. Daily image guidance for high-risk endometrial cancer results in a low incidence of acute GI/genitourinary (GU) toxicity with uncompromised tumor control at two years. Vaginal cuff translations can be substantial and may possibly result in underdosing if not properly considered.

Image guided radiation therapy may result in improved local control in locally advanced lung cancer patients.

PubMed

Kilburn, Jeremy M; Soike, Michael H; Lucas, John T; Ayala-Peacock, Diandra; Blackstock, William; Isom, Scott; Kearns, William T; Hinson, William H; Miller, Antonius A; Petty, William J; Munley, Michael T; Urbanic, James J

2016-01-01

Image guided radiation therapy (IGRT) is designed to ensure accurate and precise targeting, but whether improved clinical outcomes result is unknown. A retrospective comparison of locally advanced lung cancer patients treated with and without IGRT from 2001 to 2012 was conducted. Median local failure-free survival (LFFS), regional, locoregional failure-free survival (LRFFS), distant failure-free survival, progression-free survival, and overall survival (OS) were estimated. Univariate and multivariate models assessed the association between patient- and treatment-related covariates and local failure. A total of 169 patients were treated with definitive radiation therapy and concurrent chemotherapy with a median follow-up of 48 months in the IGRT cohort and 96 months in the non-IGRT cohort. IGRT was used in 36% (62 patients) of patients. OS was similar between cohorts (2-year OS, 47% vs 49%, P = .63). The IGRT cohort had improved 2-year LFFS (80% vs 64%, P = .013) and LRFFS (75% and 62%, P = .04). Univariate analysis revealed IGRT and treatment year improved LFFS, whereas group stage, dose, and positron emission tomography/computed tomography planning had no impact. IGRT remained significant in the multivariate model with an adjusted hazard ratio of 0.40 (P = .01). Distant failure-free survival (58% vs 59%, P = .67) did not differ significantly. IGRT with daily cone beam computed tomography confers an improvement in the therapeutic ratio relative to patients treated without this technology. Copyright © 2015 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

76 FR 31382 - Notice of Issuance of Regulatory Guide

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-31

... NUCLEAR REGULATORY COMMISSION [NRC-2010-0287] Notice of Issuance of Regulatory Guide AGENCY: Nuclear Regulatory Commission. ACTION: Notice of Issuance and Availability of Regulatory Guide 8.2, Revision 1, ``Administrative Practices in Radiation Surveys and Monitoring.'' FOR FURTHER INFORMATION...

Personalized Feedback on Staff Dose in Fluoroscopy-Guided Interventions: A New Era in Radiation Dose Monitoring.

PubMed

Sailer, Anna M; Vergoossen, Laura; Paulis, Leonie; van Zwam, Willem H; Das, Marco; Wildberger, Joachim E; Jeukens, Cécile R L P N

2017-11-01

Radiation safety and protection are a key component of fluoroscopy-guided interventions. We hypothesize that providing weekly personal dose feedback will increase radiation awareness and ultimately will lead to optimized behavior. Therefore, we designed and implemented a personalized feedback of procedure and personal doses for medical staff involved in fluoroscopy-guided interventions. Medical staff (physicians and technicians, n = 27) involved in fluoroscopy-guided interventions were equipped with electronic personal dose meters (PDMs). Procedure dose data including the dose area product and effective doses from PDMs were prospectively monitored for each consecutive procedure over an 8-month period (n = 1082). A personalized feedback form was designed displaying for each staff individually the personal dose per procedure, as well as relative and cumulative doses. This study consisted of two phases: (1) 1-5th months: Staff did not receive feedback (n = 701) and (2) 6-8th months: Staff received weekly individual dose feedback (n = 381). An anonymous evaluation was performed on the feedback and occupational dose. Personalized feedback was scored valuable by 76% of the staff and increased radiation dose awareness for 71%. 57 and 52% reported an increased feeling of occupational safety and changing their behavior because of personalized feedback, respectively. For technicians, the normalized dose was significantly lower in the feedback phase compared to the prefeedback phase: [median (IQR) normalized dose (phase 1) 0.12 (0.04-0.50) µSv/Gy cm 2 versus (phase 2) 0.08 (0.02-0.24) µSv/Gy cm 2 , p = 0.002]. Personalized dose feedback increases radiation awareness and safety and can be provided to staff involved in fluoroscopy-guided interventions.

The benefit of tissue contact monitoring with an electrical coupling index during ablation of typical atrial flutter--a prospective randomised control trial.

PubMed

Jones, Michael A; Webster, David; Wong, Kelvin C K; Hayes, Christopher; Qureshi, Norman; Rajappan, Kim; Bashir, Yaver; Betts, Timothy R

2014-12-01

We sought to investigate the use of tissue contact monitoring by means of the electrical coupling index (ECI) in a prospective randomised control trial of patients undergoing cavotricuspid isthmus (CTI) ablation for atrial flutter. Patients with ECG-documented typical flutter undergoing their first CTI ablation were randomised to ECI™-guided or non-ECI™-guided ablation. An irrigated-tip ablation catheter was used in all cases. Consecutive 50-W, 60-s radiofrequency lesions were applied to the CTI, from the tricuspid valve to inferior vena cava, with no catheter movement permitted during radiofrequency (RF) delivery. The ablation endpoint was durable CTI block at 20 min post-ablation. Patients underwent routine clinic follow-up post-operatively. A total of 101 patients (79 male), mean age 66 (+/-11), 50 ECI-guided and 51 control cases were enrolled in the study. CTI block was achieved in all. There were no acute complications. All patients were alive at follow-up. CTI block was achieved in a single pass in 36 ECI-guided and 30 control cases (p = 0.16), and at 20 min post-ablation, re-conduction was seen in 5 and 12 cases, respectively (p = 0.07). There was no significant difference in total procedure time (62.7 ± 33 vs. 62.3 ± 33 min, p = 0.92), RF requirement (580 ± 312 vs. 574 ± 287 s, p = 0.11) or fluoroscopy time (718 ± 577 vs. 721 ± 583 s, p = 0.78). After 6 ± 4 months, recurrence of flutter had occurred in 1 (2 %) ECI vs. 8 (16 %) control cases (OR 0.13, 95 % CI 0.01-1.08, p = 0.06). ECI-guided CTI ablation demonstrated a non-statistically significant reduction in late recurrence of atrial flutter, at no cost to procedural time, radiation exposure or RF requirement.

Gold-Loaded Polymeric Micelles for Computed Tomography-Guided Radiation Therapy Treatment and Radiosensitization

PubMed Central

2013-01-01

Gold nanoparticles (AuNPs) have generated interest as both imaging and therapeutic agents. AuNPs are attractive for imaging applications since they are nontoxic and provide nearly three times greater X-ray attenuation per unit weight than iodine. As therapeutic agents, AuNPs can sensitize tumor cells to ionizing radiation. To create a nanoplatform that could simultaneously exhibit long circulation times, achieve appreciable tumor accumulation, generate computed tomography (CT) image contrast, and serve as a radiosensitizer, gold-loaded polymeric micelles (GPMs) were prepared. Specifically, 1.9 nm AuNPs were encapsulated within the hydrophobic core of micelles formed with the amphiphilic diblock copolymer poly(ethylene glycol)-b-poly(ε-capralactone). GPMs were produced with low polydispersity and mean hydrodynamic diameters ranging from 25 to 150 nm. Following intravenous injection, GPMs provided blood pool contrast for up to 24 h and improved the delineation of tumor margins via CT. Thus, GPM-enhanced CT imaging was used to guide radiation therapy delivered via a small animal radiation research platform. In combination with the radiosensitizing capabilities of gold, tumor-bearing mice exhibited a 1.7-fold improvement in the median survival time, compared with mice receiving radiation alone. It is envisioned that translation of these capabilities to human cancer patients could guide and enhance the efficacy of radiation therapy. PMID:24377302

Computer tomography urography assisted real-time ultrasound-guided percutaneous nephrolithotomy on renal calculus.

PubMed

Fang, You-Qiang; Wu, Jie-Ying; Li, Teng-Cheng; Zheng, Hao-Feng; Liang, Guan-Can; Chen, Yan-Xiong; Hong, Xiao-Bin; Cai, Wei-Zhong; Zang, Zhi-Jun; Di, Jin-Ming

2017-06-01

This study aimed to assess the role of pre-designed route on computer tomography urography (CTU) in the ultrasound-guided percutaneous nephrolithotomy (PCNL) for renal calculus.From August 2013 to May 2016, a total of 100 patients diagnosed with complex renal calculus in our hospital were randomly divided into CTU group and control group (without CTU assistance). CTU was used to design a rational route for puncturing in CTU group. Ultrasound was used in both groups to establish a working trace in the operation areas. Patients' perioperative parameters and postoperative complications were recorded.All operations were successfully performed, without transferring to open surgery. Time of channel establishment in CTU group (6.5 ± 4.3 minutes) was shorter than the control group (10.0 ± 6.7 minutes) (P = .002). In addition, there was shorter operation time, lower rates of blood transfusion, secondary operation, and less establishing channels. The incidence of postoperative complications including residual stones, sepsis, severe hemorrhage, and perirenal hematoma was lower in CTU group than in control group.Pre-designing puncture route on CTU images would improve the puncturing accuracy, lessen establishing channels as well as improve the security in the ultrasound-guided PCNL for complex renal calculus, but at the cost of increased radiation exposure.

Photonic-crystal fiber as a multifunctional optical sensor and sample collector.

PubMed

Konorov, Stanislav; Zheltikov, Aleksei; Scalora, Michael

2005-05-02

Two protocols of optical sensing realized with the same photonic-crystal fiber are compared. In the first protocol, diode-laser radiation is delivered to a sample through the central core of a dual-cladding photonic-crystal fiber with a diameter of a few micrometers, while the large-diameter fiber cladding serves to collect the fluorescent response from the sample and to guide it to a detector in the backward direction. In the second scheme, liquid sample is collected by a microcapillary array in the fiber cladding and is interrogated by laser radiation guided in the fiber modes. For sample fluids with refractive indices exceeding the refractive index of the fiber material, fluid channels in photonic-crystal fibers can guide laser light by total internal reflection, providing an 80% overlap of interrogating radiation with sample fluid.

Development of a fiber-guided laser ultrasonic system resilient to high temperature and gamma radiation for nuclear power plant pipe monitoring

NASA Astrophysics Data System (ADS)

Yang, Jinyeol; Lee, Hyeonseok; Lim, Hyung Jin; Kim, Nakhyeon; Yeo, Hwasoo; Sohn, Hoon

2013-08-01

This study develops an embeddable optical fiber-guided laser ultrasonic system for structural health monitoring (SHM) of pipelines exposed to high temperature and gamma radiation inside nuclear power plants (NPPs). Recently, noncontact laser ultrasonics is gaining popularity among the SHM community because of its advantageous characteristics such as (a) scanning capability, (b) immunity against electromagnetic interference (EMI) and (c) applicability to high-temperature surfaces. However, its application to NPP pipelines has been hampered because pipes inside NPPs are often covered by insulators and/or target surfaces are not easily accessible. To overcome this problem, this study designs embeddable optical fibers and fixtures so that laser beams used for ultrasonic inspection can be transmitted between the laser sources and the target pipe. For guided-wave generation, an Nd:Yag pulsed laser coupled with an optical fiber is used. A high-power pulsed laser beam is guided through the optical fiber onto a target structure. Based on the principle of laser interferometry, the corresponding response is measured using a different type of laser beam guided by another optical fiber. All devices are especially designed to sustain high temperature and gamma radiation. The robustness/resilience of the proposed measurement system installed on a stainless steel pipe specimen has been experimentally verified by exposing the specimen to high temperature of up to 350 °C and optical fibers to gamma radiation of up to 125 kGy (20 kGy h-1).

Reconfigurable origami-inspired acoustic waveguides

PubMed Central

Babaee, Sahab; Overvelde, Johannes T. B.; Chen, Elizabeth R.; Tournat, Vincent; Bertoldi, Katia

2016-01-01

We combine numerical simulations and experiments to design a new class of reconfigurable waveguides based on three-dimensional origami-inspired metamaterials. Our strategy builds on the fact that the rigid plates and hinges forming these structures define networks of tubes that can be easily reconfigured. As such, they provide an ideal platform to actively control and redirect the propagation of sound. We design reconfigurable systems that, depending on the externally applied deformation, can act as networks of waveguides oriented along one, two, or three preferential directions. Moreover, we demonstrate that the capability of the structure to guide and radiate acoustic energy along predefined directions can be easily switched on and off, as the networks of tubes are reversibly formed and disrupted. The proposed designs expand the ability of existing acoustic metamaterials and exploit complex waveguiding to enhance control over propagation and radiation of acoustic energy, opening avenues for the design of a new class of tunable acoustic functional systems. PMID:28138527

Vector radiative transfer code SORD: Performance analysis and quick start guide

NASA Astrophysics Data System (ADS)

Korkin, Sergey; Lyapustin, Alexei; Sinyuk, Alexander; Holben, Brent; Kokhanovsky, Alexander

2017-10-01

We present a new open source polarized radiative transfer code SORD written in Fortran 90/95. SORD numerically simulates propagation of monochromatic solar radiation in a plane-parallel atmosphere over a reflecting surface using the method of successive orders of scattering (hence the name). Thermal emission is ignored. We did not improve the method in any way, but report the accuracy and runtime in 52 benchmark scenarios. This paper also serves as a quick start user's guide for the code available from ftp://maiac.gsfc.nasa.gov/pub/skorkin, from the JQSRT website, or from the corresponding (first) author.

Visibility of solid and liquid fiducial markers used for image-guided radiation therapy on optical coherence tomography: an esophageal phantom study (Conference Presentation)

NASA Astrophysics Data System (ADS)

Jelvehgaran, Pouya; Alderliesten, Tanja; Weda, Jelmer J. A.; de Bruin, Daniel M.; Faber, Dirk J.; Hulshof, Maarten C. C. M.; van Leeuwen, Ton G.; van Herk, Marcel B.; de Boer, Johannes F.

2017-03-01

Radiation therapy (RT) is used in operable and inoperable esophageal cancer patients. Endoscopic ultrasound-guided fiducial marker placement allows improved translation of the disease extent on endoscopy to computed tomography (CT) images used for RT planning and enables image-guided RT. However, microscopic tumor extent at the time of RT planning is unknown. Endoscopic optical coherence tomography (OCT) is a high-resolution (10-30µm) imaging modality with the potential for accurately determining the longitudinal disease extent. Visibility of fiducial markers on OCT is crucial for integrating OCT findings with the RT planning CT. We investigated the visibility on OCT (NinePoint Medical, Inc.) of 13 commercially available solid (Visicoil, Gold Anchor, Flexicoil, Polymark, and QLRAD) and liquid (BioXmark, Lipiodol, and Hydrogel) fiducial markers of different diameter. We designed and manufactured a set of dedicated Silicone-based esophageal phantoms to perform imaging in a controlled environment. The esophageal phantoms consist of several layers with different TiO2 concentrations to simulate the scattering properties of a typical healthy human esophagus. Markers were placed at various depths (0.5, 1.1, 2.0, and 3.0mm). OCT imaging allowed detection of all fiducial markers and phantom layers. The signal to background ratio was 6-fold higher for the solid fiducial markers than the liquid fiducial markers, yet OCT was capable of visualizing all 13 fiducial markers at all investigated depths. We conclude that RT fiducial markers can be visualized with OCT. This allows integration of OCT findings with CT for image-guided RT.

A prospective pilot study on early toxicity from a simultaneously integrated boost technique for canine sinonasal tumours using image-guided intensity-modulated radiation therapy.

PubMed

Soukup, A; Meier, V; Pot, S; Voelter, K; Rohrer Bley, C

2018-05-14

In order to overcome the common local treatment failure of canine sinonasal tumours, integrated boost techniques were tried in the cobalt/orthovoltage era, but dismissed because of unacceptable early (acute) toxicity. Intriguingly, a recent calculation study of a simultaneously integrated boost (SIB) technique for sinonasal irradiation using intensity-modulated radiation therapy (IMRT) predicted theoretical feasibility. In this prospective pilot study we applied a commonly used protocol of 10 × 4.2 Gy to the planning target volume (PTV) with a 20%-SIB dose to the gross tumour volume (GTV). Our hypothesis expected this dose escalation to be clinically tolerable if applied with image-guided IMRT. We included 9 dogs diagnosed with sinonasal tumours without local/distant metastases. For treatment planning, organs at risk were contoured according to strict anatomical guidelines. Planning volume extensions (GTV/CTV/PTV) were standardized to minimize interplanner variability. Treatments were applied with rigid patient positioning and verified daily with image guidance. After radiation therapy, we set focus on early ophthalmologic complications as well as mucosal and cutaneous toxicity. Early toxicity was evaluated at week 1, 2, 3, 8 and 12 after radiotherapy. Only mild ophthalmologic complications were found. Three patients (33%) had self-limiting moderate to severe early toxicity (grade 3 mucositis) which was managed medically. No patient developed ulcerations/haemorrhage/necrosis of skin/mucosa. The SIB protocol applied with image-guided IMRT to treat canine sinonasal tumours led to clinically acceptable side effects. The suspected increased tumour control probability and the risk of late toxicity with the used dose escalation of 20% has to be further investigated. © 2018 John Wiley & Sons Ltd.

Cost-effectiveness of the Decipher Genomic Classifier to Guide Individualized Decisions for Early Radiation Therapy After Prostatectomy for Prostate Cancer.

PubMed

Lobo, Jennifer M; Trifiletti, Daniel M; Sturz, Vanessa N; Dicker, Adam P; Buerki, Christine; Davicioni, Elai; Cooperberg, Matthew R; Karnes, R Jeffrey; Jenkins, Robert B; Den, Robert B; Showalter, Timothy N

2017-06-01

Controversy exists regarding the effectiveness of early adjuvant versus salvage radiation therapy after prostatectomy for prostate cancer. Estimates of prostate cancer progression from the Decipher genomic classifier (GC) could guide informed decision-making and improve the outcomes for patients. We developed a Markov model to compare the costs and quality-adjusted life years (QALYs) associated with GC-based treatment decisions regarding adjuvant therapy after prostatectomy with those of 2 control strategies: usual care (determined from patterns of care studies) and the alternative of 100% adjuvant radiation therapy. Using the bootstrapping method of sampling with replacement, the cases of 10,000 patients were simulated during a 10-year time horizon, with each subject having individual estimates for cancer progression (according to GC findings) and noncancer mortality (according to age). GC-based care was more effective and less costly than 100% adjuvant radiation therapy and resulted in cost savings up to an assay cost of $11,402. Compared with usual care, GC-based care resulted in more QALYs. Assuming a $4000 assay cost, the incremental cost-effectiveness ratio was $90,833 per QALY, assuming a 7% usage rate of adjuvant radiation therapy. GC-based care was also associated with a 16% reduction in the percentage of patients with distant metastasis at 5 years compared with usual care. The Decipher GC could be a cost-effective approach for genomics-driven cancer treatment decisions after prostatectomy, with improvements in estimated clinical outcomes compared with usual care. The individualized decision analytic framework applied in the present study offers a flexible approach to estimate the potential utility of genomic assays for personalized cancer medicine. Copyright © 2016 Elsevier Inc. All rights reserved.

Spacesuit Radiation Shield Design Methods

NASA Technical Reports Server (NTRS)

Wilson, John W.; Anderson, Brooke M.; Cucinotta, Francis A.; Ware, J.; Zeitlin, Cary J.

2006-01-01

Meeting radiation protection requirements during EVA is predominantly an operational issue with some potential considerations for temporary shelter. The issue of spacesuit shielding is mainly guided by the potential of accidental exposure when operational and temporary shelter considerations fail to maintain exposures within operational limits. In this case, very high exposure levels are possible which could result in observable health effects and even be life threatening. Under these assumptions, potential spacesuit radiation exposures have been studied using known historical solar particle events to gain insight on the usefulness of modification of spacesuit design in which the control of skin exposure is a critical design issue and reduction of blood forming organ exposure is desirable. Transition to a new spacesuit design including soft upper-torso and reconfigured life support hardware gives an opportunity to optimize the next generation spacesuit for reduced potential health effects during an accidental exposure.

Compact Feeding Network for Array Radiations of Spoof Surface Plasmon Polaritons

NASA Astrophysics Data System (ADS)

Xu, Jun Jun; Yin, Jia Yuan; Zhang, Hao Chi; Cui, Tie Jun

2016-03-01

We propose a splitter feeding network for array radiations of spoof surface plasmon polaritons (SPPs), which are guided by ultrathin corrugated metallic strips. Based on the coupled mode theory, SPP fields along a single waveguide in a certain frequency range can be readily coupled into two adjacent branch waveguides with the same propagation constants. We propose to load U-shaped particles anti-symmetrically at the ends of such two branch waveguides, showing a high integration degree of the feeding network. By controlling linear phase modulations produced by the U-shaped particle chain, we demonstrate theoretically and experimentally that the SPP fields based on bound modes can be efficiently radiated to far fields in broadside direction. The proposed method shows that the symmetry of electromagnetic field modes can be exploited to the SPP transmission network, providing potential solutions to compact power dividers and combiners for microwave and optical devices and systems.

Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide

NASA Astrophysics Data System (ADS)

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

2015-07-01

We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits.

Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide.

PubMed

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Kim, Un Jeong; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

2015-07-02

We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a "plasmonic via" in plasmonic nanocircuits.

Directional radiation of Babinet-inverted optical nanoantenna integrated with plasmonic waveguide

PubMed Central

Kim, Jineun; Roh, Young-Geun; Cheon, Sangmo; Jeong Kim, Un; Hwang, Sung Woo; Park, Yeonsang; Lee, Chang-Won

2015-01-01

We present a Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide. Using an integrated nanoantenna, we can couple the plasmon guide mode in a metal-insulator-metal (MIM) structure into the resonant antenna feed directly. The resonantly excited feed slot then radiates to free space and generates a magnetic dipole-like far-field pattern. The coupling efficiency of the integrated nanoantenna is calculated as being approximately 19% using a three-dimensional finite-difference time-domain (3D FDTD) simulation. By adding an auxiliary groove structure along with the feed, the radiation direction can be controlled similar to an optical Yagi-Uda antenna. We also determine, both theoretically and experimentally, that groove depth plays a significant role to function groove structure as a reflector or a director. The demonstrated Babinet-inverted optical nanoantenna integrated with a plasmonic waveguide can be used as a “plasmonic via” in plasmonic nanocircuits. PMID:26135115

Proton therapy in clinical practice

PubMed Central

Liu, Hui; Chang, Joe Y.

2011-01-01

Radiation dose escalation and acceleration improves local control but also increases toxicity. Proton radiation is an emerging therapy for localized cancers that is being sought with increasing frequency by patients. Compared with photon therapy, proton therapy spares more critical structures due to its unique physics. The physical properties of a proton beam make it ideal for clinical applications. By modulating the Bragg peak of protons in energy and time, a conformal radiation dose with or without intensity modulation can be delivered to the target while sparing the surrounding normal tissues. Thus, proton therapy is ideal when organ preservation is a priority. However, protons are more sensitive to organ motion and anatomy changes compared with photons. In this article, we review practical issues of proton therapy, describe its image-guided treatment planning and delivery, discuss clinical outcome for cancer patients, and suggest challenges and the future development of proton therapy. PMID:21527064

Complications in CT-guided Procedures: Do We Really Need Postinterventional CT Control Scans?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nattenmüller, Johanna, E-mail: johanna.nattenmueller@med.uni-heidelberg.de; Filsinger, Matthias, E-mail: Matthias_filsinger@web.de; Bryant, Mark, E-mail: mark.bryant@med.uni-heidelberg.de

2013-06-19

PurposeThe aim of this study is twofold: to determine the complication rate in computed tomography (CT)-guided biopsies and drainages, and to evaluate the value of postinterventional CT control scans.MethodsRetrospective analysis of 1,067 CT-guided diagnostic biopsies (n = 476) and therapeutic drainages (n = 591) in thoracic (n = 37), abdominal (n = 866), and musculoskeletal (ms) (n = 164) locations. Severity of any complication was categorized as minor or major. To assess the need for postinterventional CT control scans, it was determined whether complications were detected clinically, on peri-procedural scans or on postinterventional scans only.ResultsThe complication rate was 2.5 % in all procedures (n = 27), 4.4 % in diagnostic punctures, and 1.0 % inmore » drainages; 13.5 % in thoracic, 2.0 % in abdominal, and 3.0 % in musculoskeletal procedures. There was only 1 major complication (0.1 %). Pneumothorax (n = 14) was most frequent, followed by bleeding (n = 9), paresthesia (n = 2), material damage (n = 1), and bone fissure (n = 1). Postinterventional control acquisitions were performed in 65.7 % (701 of 1,067). Six complications were solely detectable in postinterventional control acquisitions (3 retroperitoneal bleeds, 3 pneumothoraces); all other complications were clinically detectable (n = 4) and/or visible in peri-interventional controls (n = 21).ConclusionComplications in CT-guided interventions are rare. Of these, thoracic interventions had the highest rate, while pneumothoraces and bleeding were most frequent. Most complications can be detected clinically or peri-interventionally. To reduce the radiation dose, postinterventional CT controls should not be performed routinely and should be restricted to complicated or retroperitoneal interventions only.« less

Limiting of microjoule femtosecond pulses in air-guided modes of a hollow photonic-crystal fiber

DOE Office of Scientific and Technical Information (OSTI.GOV)

Konorov, S.O.; Serebryannikov, E.E.; Sidorov-Biryukov, D.A.

Self-phase-modulation-induced spectral broadening of laser pulses in air-guided modes of hollow photonic-crystal fibers (PCFs) is shown to allow the creation of fiber-optic limiters for high-intensity ultrashort laser pulses. The performance of PCF limiters is analyzed in terms of elementary theory of self-phase modulation. Experiments performed with 100 fs microjoule pulses of 800 nm Ti:sapphire laser radiation demonstrate the potential of hollow PCFs as limiters for 10 MW ultrashort laser pulses and show the possibility to switch the limiting level of output radiation energy by guiding femtosecond pulses in different PCF modes.

WE-FG-BRA-07: Theranostic Nanoparticles Improve Clinical MR-Guided Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Detappe, A; Institut Lumiere-Matiere, Lyon, FR; Kunjachan, S

Purpose: MR-guided radiation therapy is a current and emerging clinical reality. We have designed and tested a silica-based gadolinium chelates nanoparticle (AGuIX) for integration with MR-guided radiation therapy. The AGuIX nanoparticles used in this study are a dual-modality probe with radiosensitization properties and better MRI contrast than current FDA-approved gadolinium chelates. In advance of an approved Phase I clinical trial, we report on the efficacy and safety in multiple animal models and clinically relevant radiation conditions. By modeling our study on current clinic workflows, we show compatibility with modern patient care, thus heightening the translational significance of this research. Methods:more » The dual imaging and therapy functionality of AGuIX was investigated in mice with clinical radiation beams while safety was evaluated in mice, and nonhuman primates after systemic injection of 0.25 mg/g of nanoparticles. MRI/ICP-MS were used to measure tumor uptake and biodistribution. Due to their small size (2–3 nm), AGuIX have good renal clearance (t1/2=19min). We performed in vitro cell uptake quantification and radiosensitization studies (clonogenic assays and DNA damage quantification). In vivo radiation therapy studies were performed with both 6MV and 6MV-FFF clinical radiation beams. Histology was performed to measure the increase in DNA damage in the tumor and to evaluate the toxicity in healthy tissues. Results: In vitro and in vivo results demonstrate statistically significant increase (P < 0.01) in DNA damage, tumor growth supression and survival (+100 days) compared to radiation alone. Negligible toxicity was observed in all of the animal models. The combination of 6MV-FFF/AGuIX demonstrated a substantial dose enhancement compared to 6MV/AGuIX (DEF = 1.36 vs. 1.22) due to the higher proportion of low energy photons. Conclusion: With demonstrated efficacy and negligible toxicity in mice and non-human primates, AGuIX is a biocompatible nanoplatform with strong translational potential for MR-guided radiation therapy.« less

Efficacy Analysis of a Script-based Guide for EVAR Execution: is it Possible to Reduce Patient Exposure to Contrast, Operative Time and Blood Loss even when Advanced Technologies are not Available?

PubMed

Molinari, Giovani José Dal Poggetto; Guillaumon, Ana Terezinha; Dalbem, Andréia Marques de Oliveira

2015-01-01

Despite the patient and medical staff exposure to radiation in endovascular aneurysm repair, the benefits of this abdominal aortic aneurysm type of surgical management are justified by minor recovery time and hospitalization, as well as an option for patients not elected to conventional open repair. In this minimally invasive surgical approach, time of procedure and radiation doses can be substantial--and the increasing frequency of these procedures and it's complexity have impelled vascular surgeons to face additional and successive risk to occupational radiation exposure. Meticulous study of the computed tomography angiography during the endovascular aneurysm repair preparation allows reduction of unnecessary radiation exposure, as also reduces consecutive image acquisition and contrast use (that may be related to renal overload in susceptible patients). Some studies have proposed strategies to optimize endovascular intervention to reduce contrast use and X-ray exposure. Although they might prove to be effective, they rely on use of additional specific and advanced equipment, available only in major centers. As an alternative to this expensive and restrict technology, it is presented a simpler technique through image manipulation on software OsiriX, aiming to reduce both exposures. To analyze the efficacy of the adoption of a study protocol and a script-based guide in preparation for endovascular aneurysm repair through verifying its impact over the surgical procedure--as referred to intravascular contrast infuse, effects over renal function, blood loss and operatory time. A longitudinal prospective study from March 2014 through March 2015, where 30 performed endovascular aneurysm repair were compared to a historic control group. The planning for endovascular aneurysm repair through the patient's tomographic image manipulation in the prospective group was performed with OsiriX MD software. A script-based guide upon gathering detailed computed tomography angiography images was elaborated by the author and distributed to the performing surgical team for appreciation, instruction and pre operatory judgment. Based upon the script, the C-arm gantry angle was specifically corrected in each case of endovascular aneurysm repair, for image optimization and aneurysm's neck visualization. Arteriography was performed under digital subtraction angiography after catheters were positioned according to predicted level description in the referred guide. Statistical analysis were performed with a significance level of 5% (P value<0.05). There was a statistically significant relationship between the two studied periods and the variables: contrast volume (284.5 vs. 31.8 mL), operative time (207.5 vs. 140.4 min.) and blood loss (798.1 vs. 204.4 mL), revealing that they are considerably larger in the historical control group than in the script guided current group. There was no difference related to the volume of contrast used in the two groups and the occurrence of renal impairment. In the present paper it was possible to demonstrate the impact of the ability to manipulate digital formats of medical images without the need of sophisticated equipment, in adoption of a guide based on the compilation of informations collected with assistance of an accessible software performed on a personal computer. Although we could not prove relation to occurrence of renal impairment, there were direct results on reduction of intravascular contrast use, even as surgical time and blood loss, compared to a previous historical period.

Excitation of parasitic waves in forward-wave amplifiers with weak guiding fields.

PubMed

Nusinovich, G S; Romero-Talamás, C A; Han, Y

2012-12-01

To produce high-power coherent electromagnetic radiation at frequencies from microwaves up to terahertz, the radiation sources should have interaction circuits of large cross sections, i.e., the sources should operate in high-order modes. In such devices, the excitation of higher-order parasitic modes near cutoff where the group velocity is small and, hence, start currents are low can be a serious problem. The problem is especially severe in the sources of coherent, phase-controlled radiation, i.e., the amplifiers or phase-locked oscillators. This problem was studied earlier [Nusinovich, Sinitsyn, and Antonsen, Phys. Rev. E 82, 046404 (2010)] for the case of electron focusing by strong guiding magnetic fields. For many applications it is desirable to minimize these focusing fields. Therefore in this paper we analyze the problem of excitation of parasitic modes near cutoff in forward-wave amplifiers with weak focusing fields. First, we study the large-signal operation of such a device with a signal wave only. Then, we analyze the self-excitation conditions of parasitic waves near cutoff in the presence of the signal wave. It is shown that the main effect is the suppression of the parasitic wave in large-signal regimes. At the same time, there is a region of device parameters where the presence of signal waves can enhance excitation of parasitic modes. The role of focusing fields in such effects is studied.

Region-of-interest image reconstruction with intensity weighting in circular cone-beam CT for image-guided radiation therapy

PubMed Central

Cho, Seungryong; Pearson, Erik; Pelizzari, Charles A.; Pan, Xiaochuan

2009-01-01

Imaging plays a vital role in radiation therapy and with recent advances in technology considerable emphasis has been placed on cone-beam CT (CBCT). Attaching a kV x-ray source and a flat panel detector directly to the linear accelerator gantry has enabled progress in target localization techniques, which can include daily CBCT setup scans for some treatments. However, with an increasing number of CT scans there is also an increasing concern for patient exposure. An intensity-weighted region-of-interest (IWROI) technique, which has the potential to greatly reduce CBCT dose, in conjunction with the chord-based backprojection-filtration (BPF) reconstruction algorithm, has been developed and its feasibility in clinical use is demonstrated in this article. A nonuniform filter is placed in the x-ray beam to create regions of two different beam intensities. In this manner, regions outside the target area can be given a reduced dose but still visualized with a lower contrast to noise ratio. Image artifacts due to transverse data truncation, which would have occurred in conventional reconstruction algorithms, are avoided and image noise levels of the low- and high-intensity regions are well controlled by use of the chord-based BPF reconstruction algorithm. The proposed IWROI technique can play an important role in image-guided radiation therapy. PMID:19472624

Development of a software based automatic exposure control system for use in image guided radiation therapy

NASA Astrophysics Data System (ADS)

Morton, Daniel R.

Modern image guided radiation therapy involves the use of an isocentrically mounted imaging system to take radiographs of a patient's position before the start of each treatment. Image guidance helps to minimize errors associated with a patients setup, but the radiation dose received by patients from imaging must be managed to ensure no additional risks. The Varian On-Board Imager (OBI) (Varian Medical Systems, Inc., Palo Alto, CA) does not have an automatic exposure control system and therefore requires exposure factors to be manually selected. Without patient specific exposure factors, images may become saturated and require multiple unnecessary exposures. A software based automatic exposure control system has been developed to predict optimal, patient specific exposure factors. The OBI system was modelled in terms of the x-ray tube output and detector response in order to calculate the level of detector saturation for any exposure situation. Digitally reconstructed radiographs are produced via ray-tracing through the patients' volumetric datasets that are acquired for treatment planning. The ray-trace determines the attenuation of the patient and subsequent x-ray spectra incident on the imaging detector. The resulting spectra are used in the detector response model to determine the exposure levels required to minimize detector saturation. Images calculated for various phantoms showed good agreement with the images that were acquired on the OBI. Overall, regions of detector saturation were accurately predicted and the detector response for non-saturated regions in images of an anthropomorphic phantom were calculated to generally be within 5 to 10 % of the measured values. Calculations were performed on patient data and found similar results as the phantom images, with the calculated images being able to determine detector saturation with close agreement to images that were acquired during treatment. Overall, it was shown that the system model and calculation method could potentially be used to predict patients' exposure factors before their treatment begins, thus preventing the need for multiple exposures.

Dental Radiology I Student Guide [and Instructor Guide].

ERIC Educational Resources Information Center

Fox Valley Technical Coll., Appleton, WI.

The dental radiology student and instructor guides provide instruction in the following units: (1) x-ray physics; (2) x-ray production; (3) radiation health and safety; (4) radiographic anatomy and pathology; (5) darkroom setup and chemistry; (6) bisecting angle technique; (7) paralleling technique; (8) full mouth survey technique--composition and…

An Educational Guide for Planning an Improved Human Environment.

ERIC Educational Resources Information Center

Kohuth, Barbara J.; Marsh, Boyd T.

This guide contains a curriculum featuring learnings and activities concerning environmental health of the home, neighborhood and city. There are six main sections to this guide: (1) Resources - containing sections on solid wastes, sound, radiation, air, water, shelter, and chemicals; (2) Environment - containing sections on positive and negative…

Directional Electrostatic Accretion Process Employing Acoustic Droplet Formation

NASA Technical Reports Server (NTRS)

Oeftering, Richard (Inventor)

1998-01-01

The present invention is directed to an apparatus for manufacturing a free standing solid metal part. In the present invention, metal droplets are ejected in a nozzleless fashion from a free surface pool of molten metal by applying focused acoustic radiation pressure. The acoustic radiation pressure is produced by high intensity acoustic tone bursts emitted from an acoustic source positioned at the bottom of the pool which directs the acoustic energy at the pool surface. The metal droplets are electrostatically charged so their trajectory can be controlled by electric fields that guide the droplets to predetermined points on a target. The droplets impinge upon the target and solidify with the target material. The accretion of the electrostatically directed solidified droplets forms the free standing metal part.

Neoadjuvant radiotherapeutic strategies in pancreatic cancer

PubMed Central

Roeder, Falk

2016-01-01

This review summarizes the current status of neoadjuvant radiation approaches in the treatment of pancreatic cancer, including a description of modern radiation techniques, and an overview on the literature regarding neoadjuvant radio- or radiochemotherapeutic strategies both for resectable and irresectable pancreatic cancer. Neoadjuvant chemoradiation for locally-advanced, primarily non- or borderline resectable pancreas cancer results in secondary resectability in a substantial proportion of patients with consecutively markedly improved overall prognosis and should be considered as possible alternative in pretreatment multidisciplinary evaluations. In resectable pancreatic cancer, outstanding results in terms of response, local control and overall survival have been observed with neoadjuvant radio- or radiochemotherapy in several phase I/II trials, which justify further evaluation of this strategy. Further investigation of neoadjuvant chemoradiation strategies should be performed preferentially in randomized trials in order to improve comparability of the current results with other treatment modalities. This should include the evaluation of optimal sequencing with newer and more potent systemic induction therapy approaches. Advances in patient selection based on new molecular markers might be of crucial interest in this context. Finally modern external beam radiation techniques (intensity-modulated radiation therapy, image-guided radiation therapy and stereotactic body radiation therapy), new radiation qualities (protons, heavy ions) or combinations with alternative boosting techniques widen the therapeutic window and contribute to the reduction of toxicity. PMID:26909133

Sacramento Regional Response Guide to Radiation Emergencies

DTIC Science & Technology

2006-09-01

emergency operations. Additionally, the utilization of thermo luminescence dosimeters ( TLD ) may be beneficial to track long term exposure for...a radiation area. Stakeholder agency emergency response equipment have been issued electronic dosimeters The purpose of the radiation dosimeter is...Incident.............................................................................84 2. Detection/ Dosimeter Equipment

Toward computer-assisted image-guided congenital heart defect repair: an initial phantom analysis.

PubMed

Kwartowitz, David M; Mefleh, Fuad N; Baker, G Hamilton

2017-10-01

Radiation exposure in interventional cardiology is an important consideration, due to risk of cancer and other morbidity to the patient and clinical staff. Cardiac catheterizations rely heavily on fluoroscopic imaging exposing both patient and clinician to ionizing radiation. An image-guided surgery system capable of facilitating cardiac catheterizations was developed and tested to evaluate dose reduction. Several electromagnetically tracked tools were constructed specifically a 7-Fr catheter with five 5-degree-of-freedom magnetic seeds. Catheter guidance was accomplished using our image guidance system Kit for Navigation by Image-Focused Exploration and fluoroscopy alone. A cardiac phantom was designed and 3D printed to validate the image guidance procedure. In mock procedures, an expert clinician guided and deployed an occluder across the septal defect of the phantom heart. The image guidance method resulted in a dose of 1.26 mSv of radiation dose per procedure, while traditional guidance resulted in a dose of 3.33 mSv. Average overall dose savings for the image-guided method was nearly 2.07 mSv or 62 %. The work showed significant ([Formula: see text]) decrease in radiation dose with use of image guidance methods at the expense of a modest increase in procedure time. This study lays the groundwork for further exploration of image guidance applications in pediatric cardiology.

Development of an ultrasmall C-band linear accelerator guide for a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head.

PubMed

Kamino, Yuichiro; Miura, Sadao; Kokubo, Masaki; Yamashita, Ichiro; Hirai, Etsuro; Hiraoka, Masahiro; Ishikawa, Junzo

2007-05-01

We are developing a four-dimensional image-guided radiotherapy system with a gimbaled x-ray head. It is capable of pursuing irradiation and delivering irradiation precisely with the help of an agile moving x-ray head on the gimbals. Requirements for the accelerator guide were established, system design was developed, and detailed design was conducted. An accelerator guide was manufactured and basic beam performance and leakage radiation from the accelerator guide were evaluated at a low pulse repetition rate. The accelerator guide including the electron gun is 38 cm long and weighs about 10 kg. The length of the accelerating structure is 24.4 cm. The accelerating structure is a standing wave type and is composed of the axial-coupled injector section and the side-coupled acceleration cavity section. The injector section is composed of one prebuncher cavity, one buncher cavity, one side-coupled half cavity, and two axial coupling cavities. The acceleration cavity section is composed of eight side-coupled nose reentrant cavities and eight coupling cavities. The electron gun is a diode-type gun with a cerium hexaboride (CeB6) direct heating cathode. The accelerator guide can be operated without any magnetic focusing device. Output beam current was 75 mA with a transmission efficiency of 58%, and the average energy was 5.24 MeV. Beam energy was distributed from 4.95 to 5.6 MeV. The beam profile, measured 88 mm from the beam output hole on the axis of the accelerator guide, was 0.7 mm X 0.9 mm full width at half maximum (FWHM) width. The beam loading line was 5.925 (MeV)-Ib (mA) X 0.00808 (MeV/mA), where Ib is output beam current. The maximum radiation leakage of the accelerator guide at 100 cm from the axis of the accelerator guide was calculated as 0.33 cGy/min at the rated x-ray output of 500 cGy/min from the measured value. This leakage requires no radiation shielding for the accelerator guide itself per IEC 60601-2-1.

Radiation Exposure of Interventional Radiologists During Computed Tomography Fluoroscopy-Guided Renal Cryoablation and Lung Radiofrequency Ablation: Direct Measurement in a Clinical Setting.

PubMed

Matsui, Yusuke; Hiraki, Takao; Gobara, Hideo; Iguchi, Toshihiro; Fujiwara, Hiroyasu; Kawabata, Takahiro; Yamauchi, Takatsugu; Yamaguchi, Takuya; Kanazawa, Susumu

2016-06-01

Computed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking. Radiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator's finger skin was measured using thermoluminescent dosimeter rings. The mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator's finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA. Radiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.

Sun, UV Radiation and Your Eyes

MedlinePlus

... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Academy Publications EyeNet Ophthalmology ... Plastic Surgery Center Laser Surgery Education Center Redmond Ethics Center Global Ophthalmology Guide Find an Ophthalmologist Advanced ...

A cost effective and high fidelity fluoroscopy simulator using the Image-Guided Surgery Toolkit (IGSTK)

NASA Astrophysics Data System (ADS)

Gong, Ren Hui; Jenkins, Brad; Sze, Raymond W.; Yaniv, Ziv

2014-03-01

The skills required for obtaining informative x-ray fluoroscopy images are currently acquired while trainees provide clinical care. As a consequence, trainees and patients are exposed to higher doses of radiation. Use of simulation has the potential to reduce this radiation exposure by enabling trainees to improve their skills in a safe environment prior to treating patients. We describe a low cost, high fidelity, fluoroscopy simulation system. Our system enables operators to practice their skills using the clinical device and simulated x-rays of a virtual patient. The patient is represented using a set of temporal Computed Tomography (CT) images, corresponding to the underlying dynamic processes. Simulated x-ray images, digitally reconstructed radiographs (DRRs), are generated from the CTs using ray-casting with customizable machine specific imaging parameters. To establish the spatial relationship between the CT and the fluoroscopy device, the CT is virtually attached to a patient phantom and a web camera is used to track the phantom's pose. The camera is mounted on the fluoroscope's intensifier and the relationship between it and the x-ray source is obtained via calibration. To control image acquisition the operator moves the fluoroscope as in normal operation mode. Control of zoom, collimation and image save is done using a keypad mounted alongside the device's control panel. Implementation is based on the Image-Guided Surgery Toolkit (IGSTK), and the use of the graphics processing unit (GPU) for accelerated image generation. Our system was evaluated by 11 clinicians and was found to be sufficiently realistic for training purposes.

Interactive contour delineation and refinement in treatment planning of image‐guided radiation therapy

PubMed Central

Zhou, Wu

2014-01-01

The accurate contour delineation of the target and/or organs at risk (OAR) is essential in treatment planning for image‐guided radiation therapy (IGRT). Although many automatic contour delineation approaches have been proposed, few of them can fulfill the necessities of applications in terms of accuracy and efficiency. Moreover, clinicians would like to analyze the characteristics of regions of interests (ROI) and adjust contours manually during IGRT. Interactive tool for contour delineation is necessary in such cases. In this work, a novel approach of curve fitting for interactive contour delineation is proposed. It allows users to quickly improve contours by a simple mouse click. Initially, a region which contains interesting object is selected in the image, then the program can automatically select important control points from the region boundary, and the method of Hermite cubic curves is used to fit the control points. Hence, the optimized curve can be revised by moving its control points interactively. Meanwhile, several curve fitting methods are presented for the comparison. Finally, in order to improve the accuracy of contour delineation, the process of the curve refinement based on the maximum gradient magnitude is proposed. All the points on the curve are revised automatically towards the positions with maximum gradient magnitude. Experimental results show that Hermite cubic curves and the curve refinement based on the maximum gradient magnitude possess superior performance on the proposed platform in terms of accuracy, robustness, and time calculation. Experimental results of real medical images demonstrate the efficiency, accuracy, and robustness of the proposed process in clinical applications. PACS number: 87.53.Tf PMID:24423846

Characterization and evaluation of ionizing and non-ionizing imaging systems used in state of the art image-guided radiation therapy techniques

NASA Astrophysics Data System (ADS)

Stanley, Dennis Nichols

With the growing incidence of cancer worldwide, the need for effective cancer treatment is paramount. Currently, radiation therapy exists as one of the few effective, non-invasive methods of reducing tumor size and has the capability for the elimination of localized tumors. Radiation therapy utilizes non-invasive external radiation to treat localized cancers but to be effective, physicians must be able to visualize and monitor the internal anatomy and target displacements. Image-Guided Radiation Therapy frequently utilizes planar and volumetric imaging during a course of radiation therapy to improve the precision and accuracy of the delivered treatment to the internal anatomy. Clinically, visualization of the internal anatomy allows physicians to refine the treatment to include as little healthy tissue as possible. This not only increases the effectiveness of treatment by damaging only the tumor but also increases the quality of life for the patient by decreasing the amount of healthy tissue damaged. Image-Guided Radiation Therapy is commonly used to treat tumors in areas of the body that are prone to movement, such as the lungs, liver, and prostate, as well as tumors located close to critical organs and tissues such as the tumors in the brain and spinal cord. Image-Guided Radiation Therapy can utilize both ionizing modalities, like x-ray based planar radiography and cone-beam CT, and nonionizing modalities like MRI, ultrasound and video-based optical scanning systems. Currently ionizing modalities are most commonly utilized for their ability to visualize and monitor internal anatomy but cause an increase to the total dose to the patient. Nonionizing imaging modalities allow frequent/continuous imaging without the increase in dose; however, they are just beginning to be clinically implemented in radiation oncology. With the growing prevalence and variety of Image-Guided Radiation Therapy imaging modalities the ability to evaluate the overall image quality, monitor the stability of the imaging systems and characterize each system are important to ensuring the consistency and effectiveness of the overall treatment. Image-Guided Radiation Therapy quality assurance allows a method of quantifying the accuracy and stability of the imaging systems. Understanding how the ionizing imaging systems operate and change over time allows for a more effective overall treatment and will be the focus of the first step of this project. In each of the first three aims, different ionizing imaging modalities will be evaluated for their temporal stability and a record of the determined tolerance level will be reported. The Second step of this project will be a characterization of the accuracy and performance of the new C-Rad CatalystHD a video-based, surface-imaging guided patient localization system. The catalyst will be analyzed for it accuracy of setup and patient positing, intra- and inter- fraction motion detection as well as its respiratory gating capabilities. The final step of this project will be to use the well-established accuracy of the XVI volumetric imaging system as a benchmark to assess the accuracy of the C-Rad CatalystHD system for use in pretreatment patient position verification for cranial stereotactic procedures. The treatment of brain lesions generally requires a very high degree of precision due to relatively small target sizes, close proximity to eloquent areas of the brain, and large, ablative doses being delivered. Stringent accuracy in imaging is needed to verify and monitor the correct spatial delivery of radiation throughout treatment. In order to investigate if the CatalystHD system is a capable imaging system for such deliveries, the system will need to be assessed and benchmarked against the XVI in a phantom geometry. By doing so, the currently unproven utility of the CatalystHD system for cranial stereotactic delivery may be established. (Abstract shortened by ProQuest.).

Positron emission tomography-guided conformal fast neutron therapy for glioblastoma multiforme

PubMed Central

Stelzer, Keith J.; Douglas, James G.; Mankoff, David A.; Silbergeld, Daniel L.; Krohn, Kenneth A.; Laramore, George E.; Spence, Alexander M.

2008-01-01

Glioblastoma multiforme (GBM) continues to be a difficult therapeutic challenge. Our study was conducted to determine whether improved survival and tumor control could be achieved with modern delivery of fast neutron radiation using three-dimensional treatment planning. Ten patients were enrolled. Eligibility criteria included pathologic diagnosis of GBM, age ≥ 18 years, and KPS ≥60. Patients underwent MRI and 18F-fluorodeoxyglucose PET (FDG PET) as part of initial three-dimensional treatment planning. Sequential targets were treated with noncoplanar fields to a total dose of 18 Gy in 16 fractions over 4 weeks. Median and 1-year overall survival were 55 weeks and 60%, respectively. One patient remains alive at last follow-up 255 weeks after diagnosis. Median progression-free survival was 16 weeks, and all patients had tumor progression by 39 weeks. Treatment was clinically well tolerated, but evidence of mild to moderate gliosis and microvascular sclerosis consistent with radiation injury was observed at autopsy in specimens taken from regions of contralateral brain that received approximately 6–10 Gy. Fast neutron radiation using modern imaging, treatment planning, and beam delivery was feasible to a total dose of 18 Gy, but tumor control probability was poor in comparison to that predicted from a dose-response model based on older studies. Steep dose-response curves for both tumor control and neurotoxicity continue to present a challenge to establishing a therapeutic window for fast neutron radiation in GBM, even with modern techniques. PMID:18055860

Risk-benefit analysis of navigation techniques for vertebral transpedicular instrumentation: a prospective study.

PubMed

Noriega, David C; Hernández-Ramajo, Rubén; Rodríguez-Monsalve Milano, Fiona; Sanchez-Lite, Israel; Toribio, Borja; Ardura, Francisco; Torres, Ricardo; Corredera, Raul; Kruger, Antonio

2017-01-01

Pedicle screws in spinal surgery have allowed greater biomechanical stability and higher fusion rates. However, malposition is very common and may cause neurologic, vascular, and visceral injuries and compromise mechanical stability. The purpose of this study was to compare the malposition rate between intraoperative computed tomography (CT) scan assisted-navigation and free-hand fluoroscopy-guided techniques for placement of pedicle screw instrumentation. This is a prospective, randomized, observational study. A total of 114 patients were included: 58 in the assisted surgery group and 56 in the free-hand fluoroscopy-guided surgery group. Analysis of screw position was assessed using the Heary classification. Breach severity was defined according to the Gertzbein classification. Radiation doses were evaluated using thermoluminescent dosimeters, and estimates of effective and organ doses were made based on scan technical parameters. Consecutive patients with degenerative disease, who underwent surgical procedures using the free-hand, or intraoperative navigation technique for placement of transpedicular instrumentation, were included in the study. Forty-four out of 625 implanted screws were malpositioned: 11 (3.6%) in the navigated surgery group and 33 (10.3%) in the free-hand group (p<.001). Screw position according to the Heary scale was Grade II (4 navigated surgery, 6 fluoroscopy guided), Grade III (3 navigated surgery, 11 fluoroscopy guided), Grade IV (4 navigated surgery, 16 fluoroscopy guided), and Grade V (1 fluoroscopy guided). There was only one symptomatic case in the conventional surgery group. Breach severity was seven Grade A and four Grade B in the navigated surgery group, and eight Grade A, 24 Grade B, and one Grade C in free-hand fluoroscopy-guided surgery group. Radiation received per patient was 5.8 mSv (4.8-7.3). The median dose received in the free-hand fluoroscopy group was 1 mGy (0.8-1.1). There was no detectable radiation level in the navigation-assisted surgery group, whereas the effective dose was 10 µGy in the free-hand fluoroscopy-guided surgery group. Malposition rate, both symptomatic and asymptomatic, in spinal surgery is reduced when using CT-guided placement of transpedicular instrumentation compared with placement under fluoroscopic guidance, with radiation values within the safety limits for health. Larger studies are needed to determine risk-benefit in these patients. Copyright © 2016 Elsevier Inc. All rights reserved.

TH-F-202-03: Advances in MRI for Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, J.

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

TH-F-202-00: MRI for Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

Controlling dynamics of imploded core plasma for fast ignition

NASA Astrophysics Data System (ADS)

Nagatomo, H.; Johzaki, T.; Sunahara, A.; Shiraga, H.; Sakagami, H.; Cai, H.; Mima, K.

2010-08-01

In the Fast ignition, formation of highly compressed core plasma is one of critical issue. In this work, the effect hydrodynamic instability in cone-guided shell implosion is studied. Two-dimensional radiation hydrodynamic simulations are carried out where realistic seeds of Rayleigh-Taylor instability are imposed. Preliminary results suggest that the instability reduces implosion performance, such as implosion velocity, areal density, and maximum density. In perturbed target implosion, the break-up time of the tip of the cone is earlier than that of ideal unperturbed target implosion case. This is crucial matter for the Fast ignition because the pass for the heating laser is filled with plasma before the shot of heating laser. A sophisticated implosion design of stable and low in-flight aspect ratio is necessary for cone-guided shell implosion.

Guiding of relativistic electron beams in solid targets by resistively controlled magnetic fields.

PubMed

Kar, S; Robinson, A P L; Carroll, D C; Lundh, O; Markey, K; McKenna, P; Norreys, P; Zepf, M

2009-02-06

Guided transport of a relativistic electron beam in solid is achieved experimentally by exploiting the strong magnetic fields created at the interface of two metals of different electrical resistivities. This is of substantial relevance to the Fast Ignitor approach to fusion energy production [M. Tabak, Phys. Plasmas 12, 057305 (2005)10.1063/1.1871246], since it allows the electron deposition to be spatially tailored-thus adding substantial design flexibility and preventing inefficiencies due to electron beam spreading. In the experiment, optical transition radiation and thermal emission from the target rear surface provide a clear signature of the electron confinement within a high resistivity tin layer sandwiched transversely between two low resistivity aluminum slabs. The experimental data are found to agree well with numerical simulations.

Omni-directional L-band antenna for mobile communications

NASA Technical Reports Server (NTRS)

Kim, C. S.; Moldovan, N.; Kijesky, J.

1988-01-01

The principle and design of an L-band omni-directional mobile communication antenna are discussed. The antenna is a circular wave guide aperture with hybrid circuits attached to higher order mode excitation. It produces polarized and symmetric two split beams in elevation. The circular waveguide is fed by eight probes with a 90 degree phase shift between their inputs. Radiation pattern characteristics are controlled by adjusting the aperture diameter and mode excitation. This antenna satisfies gain requirements as well as withstanding the harsh environment.

Hydrogel Spacer Prospective Multicenter Randomized Controlled Pivotal Trial: Dosimetric and Clinical Effects of Perirectal Spacer Application in Men Undergoing Prostate Image Guided Intensity Modulated Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mariados, Neil, E-mail: nmariados@ampofny.com; Sylvester, John; Shah, Dhiren

2015-08-01

Purpose: Perirectal spacing, whereby biomaterials are placed between the prostate and rectum, shows promise in reducing rectal dose during prostate cancer radiation therapy. A prospective multicenter randomized controlled pivotal trial was performed to assess outcomes following absorbable spacer (SpaceOAR system) implantation. Methods and Materials: Overall, 222 patients with clinical stage T1 or T2 prostate cancer underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans for treatment planning, followed with fiducial marker placement, and were randomized to receive spacer injection or no injection (control). Patients received postprocedure CT and MRI planning scans and underwent image guided intensity modulated radiation therapymore » (79.2 Gy in 1.8-Gy fractions). Spacer safety and impact on rectal irradiation, toxicity, and quality of life were assessed throughout 15 months. Results: Spacer application was rated as “easy” or “very easy” 98.7% of the time, with a 99% hydrogel placement success rate. Perirectal spaces were 12.6 ± 3.9 mm and 1.6 ± 2.0 mm in the spacer and control groups, respectively. There were no device-related adverse events, rectal perforations, serious bleeding, or infections within either group. Pre-to postspacer plans had a significant reduction in mean rectal V70 (12.4% to 3.3%, P<.0001). Overall acute rectal adverse event rates were similar between groups, with fewer spacer patients experiencing rectal pain (P=.02). A significant reduction in late (3-15 months) rectal toxicity severity in the spacer group was observed (P=.04), with a 2.0% and 7.0% late rectal toxicity incidence in the spacer and control groups, respectively. There was no late rectal toxicity greater than grade 1 in the spacer group. At 15 months 11.6% and 21.4% of spacer and control patients, respectively, experienced 10-point declines in bowel quality of life. MRI scans at 12 months verified spacer absorption. Conclusions: Spacer application was well tolerated. Increased perirectal space reduced rectal irradiation, reduced rectal toxicity severity, and decreased rates of patients experiencing declines in bowel quality of life. The spacer appears to be an effective tool, potentially enabling advanced prostate RT protocols.« less

Hydrogel Spacer Prospective Multicenter Randomized Controlled Pivotal Trial: Dosimetric and Clinical Effects of Perirectal Spacer Application in Men Undergoing Prostate Image Guided Intensity Modulated Radiation Therapy.

PubMed

Mariados, Neil; Sylvester, John; Shah, Dhiren; Karsh, Lawrence; Hudes, Richard; Beyer, David; Kurtzman, Steven; Bogart, Jeffrey; Hsi, R Alex; Kos, Michael; Ellis, Rodney; Logsdon, Mark; Zimberg, Shawn; Forsythe, Kevin; Zhang, Hong; Soffen, Edward; Francke, Patrick; Mantz, Constantine; Rossi, Peter; DeWeese, Theodore; Hamstra, Daniel A; Bosch, Walter; Gay, Hiram; Michalski, Jeff

2015-08-01

Perirectal spacing, whereby biomaterials are placed between the prostate and rectum, shows promise in reducing rectal dose during prostate cancer radiation therapy. A prospective multicenter randomized controlled pivotal trial was performed to assess outcomes following absorbable spacer (SpaceOAR system) implantation. Overall, 222 patients with clinical stage T1 or T2 prostate cancer underwent computed tomography (CT) and magnetic resonance imaging (MRI) scans for treatment planning, followed with fiducial marker placement, and were randomized to receive spacer injection or no injection (control). Patients received postprocedure CT and MRI planning scans and underwent image guided intensity modulated radiation therapy (79.2 Gy in 1.8-Gy fractions). Spacer safety and impact on rectal irradiation, toxicity, and quality of life were assessed throughout 15 months. Spacer application was rated as "easy" or "very easy" 98.7% of the time, with a 99% hydrogel placement success rate. Perirectal spaces were 12.6 ± 3.9 mm and 1.6 ± 2.0 mm in the spacer and control groups, respectively. There were no device-related adverse events, rectal perforations, serious bleeding, or infections within either group. Pre-to postspacer plans had a significant reduction in mean rectal V70 (12.4% to 3.3%, P<.0001). Overall acute rectal adverse event rates were similar between groups, with fewer spacer patients experiencing rectal pain (P=.02). A significant reduction in late (3-15 months) rectal toxicity severity in the spacer group was observed (P=.04), with a 2.0% and 7.0% late rectal toxicity incidence in the spacer and control groups, respectively. There was no late rectal toxicity greater than grade 1 in the spacer group. At 15 months 11.6% and 21.4% of spacer and control patients, respectively, experienced 10-point declines in bowel quality of life. MRI scans at 12 months verified spacer absorption. Spacer application was well tolerated. Increased perirectal space reduced rectal irradiation, reduced rectal toxicity severity, and decreased rates of patients experiencing declines in bowel quality of life. The spacer appears to be an effective tool, potentially enabling advanced prostate RT protocols. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Modern Radiation Therapy for Hodgkin Lymphoma: Field and Dose Guidelines From the International Lymphoma Radiation Oncology Group (ILROG)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Specht, Lena, E-mail: lena.specht@regionh.dk; Yahalom, Joachim; Illidge, Tim

2014-07-15

Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solelymore » on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the use of ISRT has not yet been validated in a formal study, it is more conservative than INRT, accounting for suboptimal information and appropriately designed for safe local disease control. The goal of modern smaller field radiation therapy is to reduce both treatment volume and treatment dose while maintaining efficacy and minimizing acute and late sequelae. This review is a consensus of the International Lymphoma Radiation Oncology Group (ILROG) Steering Committee regarding the modern approach to RT in the treatment of HL, outlining a new concept of ISRT in which reduced treatment volumes are planned for the effective control of involved sites of HL. Nodal and extranodal non-Hodgkin lymphomas (NHL) are covered separately by ILROG guidelines.« less

Modern radiation therapy for Hodgkin lymphoma: field and dose guidelines from the international lymphoma radiation oncology group (ILROG).

PubMed

Specht, Lena; Yahalom, Joachim; Illidge, Tim; Berthelsen, Anne Kiil; Constine, Louis S; Eich, Hans Theodor; Girinsky, Theodore; Hoppe, Richard T; Mauch, Peter; Mikhaeel, N George; Ng, Andrea

2014-07-15

Radiation therapy (RT) is the most effective single modality for local control of Hodgkin lymphoma (HL) and an important component of therapy for many patients. These guidelines have been developed to address the use of RT in HL in the modern era of combined modality treatment. The role of reduced volumes and doses is addressed, integrating modern imaging with 3-dimensional (3D) planning and advanced techniques of treatment delivery. The previously applied extended field (EF) and original involved field (IF) techniques, which treated larger volumes based on nodal stations, have now been replaced by the use of limited volumes, based solely on detectable nodal (and extranodal extension) involvement at presentation, using contrast-enhanced computed tomography, positron emission tomography/computed tomography, magnetic resonance imaging, or a combination of these techniques. The International Commission on Radiation Units and Measurements concepts of gross tumor volume, clinical target volume, internal target volume, and planning target volume are used for defining the targeted volumes. Newer treatment techniques, including intensity modulated radiation therapy, breath-hold, image guided radiation therapy, and 4-dimensional imaging, should be implemented when their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control. The highly conformal involved node radiation therapy (INRT), recently introduced for patients for whom optimal imaging is available, is explained. A new concept, involved site radiation therapy (ISRT), is introduced as the standard conformal therapy for the scenario, commonly encountered, wherein optimal imaging is not available. There is increasing evidence that RT doses used in the past are higher than necessary for disease control in this era of combined modality therapy. The use of INRT and of lower doses in early-stage HL is supported by available data. Although the use of ISRT has not yet been validated in a formal study, it is more conservative than INRT, accounting for suboptimal information and appropriately designed for safe local disease control. The goal of modern smaller field radiation therapy is to reduce both treatment volume and treatment dose while maintaining efficacy and minimizing acute and late sequelae. This review is a consensus of the International Lymphoma Radiation Oncology Group (ILROG) Steering Committee regarding the modern approach to RT in the treatment of HL, outlining a new concept of ISRT in which reduced treatment volumes are planned for the effective control of involved sites of HL. Nodal and extranodal non-Hodgkin lymphomas (NHL) are covered separately by ILROG guidelines. Copyright © 2014 Elsevier Inc. All rights reserved.

Federal Guidance Report No. 10: The Radioactivity Concentration Guides

EPA Pesticide Factsheets

This document provides the calculation of derived limits for the 1960 Radiation Protection Guides reflecting updated models for dosimetry and biological transport. This report has been superseded by Federal Guidance Report No. 11.

Electromagnetically driven radiative shocks and their measurements

NASA Astrophysics Data System (ADS)

Kondo, K.; Nakajima, M.; Kawamura, T.; Horioka, K.

2006-06-01

Experimental results on a generation of strong shocks in a compact pulse power device are reported. To make a strong and plain shock wave, electrodes are tapered and an acrylic guiding tube is located on the top of the electrodes. It drives a quasi-one-dimensional strong shock in the guiding tube. When the front speed is more than the critical speed Drad, an interesting structure is confirmed at the shock front, which indicate a phenomenon proceeded by the radiative transport.

Guided Radiation Beams in Free Electron Lasers.

DTIC Science & Technology

1988-05-19

the electron beam in an FEL that the radiation beam will remain guided. 0 20 II. Refractive Index Associated with FELs In our model, the vector ...eIAw/ymOc(exp(ikwz) + c.c.) ex/2 , is the wiggle velocity, y is the Lorentz factor, Aw is the vector potential amplitude of the planar wiggler...Balboa Avenue Palo Alto, CA 94303 San Diego, CA 92123 38 Dr. S. Krinsky Nat. Synchrotron Light Source Dr. Michael Lavan Brookhaven National Laboratory U.S

A method to measure internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures

NASA Astrophysics Data System (ADS)

Tian, Qijie; Chang, Songtao; Li, Zhou; He, Fengyun; Qiao, Yanfeng

2017-03-01

The suppression level of internal stray radiation is a key criterion for infrared imaging systems, especially for high-precision cryogenic infrared imaging systems. To achieve accurate measurement for internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures, a measurement method, which is based on radiometric calibration, is presented in this paper. First of all, the calibration formula is deduced considering the integration time, and the effect of ambient temperature on internal stray radiation is further analyzed in detail. Then, an approach is proposed to measure the internal stray radiation of cryogenic infrared imaging systems under various ambient temperatures. By calibrating the system under two ambient temperatures, the quantitative relation between the internal stray radiation and the ambient temperature can be acquired, and then the internal stray radiation of the cryogenic infrared imaging system under various ambient temperatures can be calculated. Finally, several experiments are performed in a chamber with controllable inside temperatures to evaluate the effectiveness of the proposed method. Experimental results indicate that the proposed method can be used to measure internal stray radiation with high accuracy at various ambient temperatures and integration times. The proposed method has some advantages, such as simple implementation and the capability of high-precision measurement. The measurement results can be used to guide the stray radiation suppression and to test whether the internal stray radiation suppression performance meets the requirement or not.

BEIR-III report and its implications for radiation protection and public health policy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fabrikant, J.I.

1980-03-01

A general background is given of the implications the BEIR-III Report may have on societal decision-making in the regulation of activities concerned with the health effects of low-level radiation. The scientific basis for establishing appropriate radiation protection guides are discussed. (ACR)

Investigation of critical parameters controlling the efficiency of associative ionization

NASA Astrophysics Data System (ADS)

Le Padellec, A.; Launoy, T.; Dochain, A.; Urbain, X.

2017-05-01

This paper compiles our merged-beam experimental findings for the associative ionization (AI) process from charged reactants, with the aim of guiding future investigations with e.g. the double electrostatic ion storage ring DESIREE in Stockholm. A reinvestigation of the isotopic effect in H-(D-) + He+ collisions is presented, along with a review of {{{H}}}3+ and NO+ production by AI involving ion pairs or excited neutrals, and put in perspective with the mutual neutralization and radiative association reactions. Critical parameters are identified and evaluated for their systematic role in controlling the magnitude of the cross section: isotopic substitution, exothermicity, electronic state density, and spin statistics.

Precision of computer-assisted core decompression drilling of the knee.

PubMed

Beckmann, J; Goetz, J; Bäthis, H; Kalteis, T; Grifka, J; Perlick, L

2006-06-01

Core decompression by exact drilling into the ischemic areas is the treatment of choice in early stages of osteonecrosis of the femoral condyle. Computer-aided surgery might enhance the precision of the drilling and lower the radiation exposure time of both staff and patients. The aim of this study was to evaluate the precision of the fluoroscopically based VectorVision-navigation system in an in vitro model. Thirty sawbones were prepared with a defect filled up with a radiopaque gypsum sphere mimicking the osteonecrosis. 20 sawbones were drilled by guidance of an intraoperative navigation system VectorVision (BrainLAB, Munich, Germany). Ten sawbones were drilled by fluoroscopic control only. A statistically significant difference with a mean distance of 0.58 mm in the navigated group and 0.98 mm in the control group regarding the distance to the desired mid-point of the lesion could be stated. Significant difference was further found in the number of drilling corrections as well as radiation time needed. The fluoroscopic-based VectorVision-navigation system shows a high feasibility and precision of computer-guided drilling with simultaneously reduction of radiation time and therefore could be integrated into clinical routine.

Development and evaluation of multi-energy PbO dosimeter for quality assurance of image-guide radiation therapy devices

NASA Astrophysics Data System (ADS)

Kim, Kyo-Tae; Heo, Ye-Ji; Han, Moo-Jae; Oh, Kyung-Min; Lee, Young-Kyu; Kim, Shin-Wook; Park, Sung-Kwang

2017-04-01

In radiation therapy, accurate radiotherapy treatment plan (RTP) reproduction is necessary to optimize the clinical results. Thus, attempts have recently been made to ensure high RTP reproducibility using image-guide radiation therapy (IGRT) technology. However, the clinical use of digital X-ray equipment requires extended quality assurance (QA) for those devices, since the IGRT device quality determines the precision of intensity-modulated radiation therapy. The study described in this paper was focused on developing a multi-energy PbO dosimeter for IGRT device QA. The Schottky-type polycrystalline PbO dosimeter with a Au/PbO/ITO structure was evaluated by comparing its response coincidence, dose linearity, measurement reproducibility, linear attenuation coefficient, and percent depth dose with those of Si diode and standard ionization chamber dosimeters.

Detecting Intra-Fraction Motion in Patients Undergoing Radiation Treatment Using a Low-Cost Wireless Accelerometer

PubMed Central

Farahmand, Farid; Khadivi, Kevin O.; Rodrigues, Joel J. P. C.

2009-01-01

The utility of a novel, high-precision, non-intrusive, wireless, accelerometer-based patient orientation monitoring system (APOMS) in determining orientation change in patients undergoing radiation treatment is reported here. Using this system a small wireless accelerometer sensor is placed on a patient’s skin, broadcasting its orientation to the receiving station connected to a PC in the control area. A threshold-based algorithm is developed to identify the exact amount of the patient’s head orientation change. Through real-time measurements, an audible alarm can alert the radiation therapist if the user-defined orientation threshold is violated. Our results indicate that, in spite of its low-cost and simplicity, the APOMS is highly sensitive and offers accurate measurements. Furthermore, the APOMS is patient friendly, vendor neutral, and requires minimal user training. The versatile architecture of the APOMS makes it potentially suitable for variety of applications, including study of correlation between external and internal markers during Image-Guided Radiation Therapy (IGRT), with no major changes in hardware setup or algorithm. PMID:22423196

MR-guided prostate interventions.

PubMed

Tempany, Clare; Straus, Sarah; Hata, Nobuhiko; Haker, Steven

2008-02-01

In this article the current issues of diagnosis and detection of prostate cancer are reviewed. The limitations for current techniques are highlighted and some possible solutions with MR imaging and MR-guided biopsy approaches are reviewed. There are several different biopsy approaches under investigation. These include transperineal open magnet approaches to closed-bore 1.5T transrectal biopsies. The imaging, image processing, and tracking methods are also discussed. In the arena of therapy, MR guidance has been used in conjunction with radiation methods, either brachytherapy or external delivery. The principles of the radiation treatment, the toxicities, and use of images are outlined. The future role of imaging and image-guided interventions lie with providing a noninvasive surrogate for cancer surveillance or monitoring treatment response. The shift to minimally invasive focal therapies has already begun and will be very exciting when MR-guided focused ultrasound surgery reaches its full potential. (Copyright) 2008 Wiley-Liss, Inc.

MR-Guided Prostate Interventions

PubMed Central

Tempany, Clare; Straus, Sarah; Hata, Nobuhiko; Haker, Steven

2009-01-01

In this article the current issues of diagnosis and detection of prostate cancer are reviewed. The limitations for current techniques are highlighted and some possible solutions with MR imaging and MR-guided biopsy approaches are reviewed. There are several different biopsy approaches under investigation. These include transperineal open magnet approaches to closed-bore 1.5T transrectal biopsies. The imaging, image processing, and tracking methods are also discussed. In the arena of therapy, MR guidance has been used in conjunction with radiation methods, either brachytherapy or external delivery. The principles of the radiation treatment, the toxicities, and use of images are outlined. The future role of imaging and image-guided interventions lie with providing a noninvasive surrogate for cancer surveillance or monitoring treatment response. The shift to minimally invasive focal therapies has already begun and will be very exciting when MR-guided focused ultrasound surgery reaches its full potential. PMID:18219689

Atmospheric Sciences. Test Edition. AAAS Study Guides on Contemporary Problems, No. 6.

ERIC Educational Resources Information Center

Schaefer, Vincent J.; Mohnen, Volker A.

This is one of several study guides on contemporary problems produced by the American Association for the Advancement of Science with support of the National Science Foundation. This study guide includes the following sections: (1) Solar Radiation and Its Interaction with the Earth's Atmosphere System; (2) The Water Cycle; (3) Fundamentals of Air…

Thermal Investigation of Interaction between High-power CW-laser Radiation and a Water-jet

NASA Astrophysics Data System (ADS)

Brecher, Christian; Janssen, Henning; Eckert, Markus; Schmidt, Florian

The technology of a water guided laser beam has been industrially established for micro machining. Pulsed laser radiation is guided via a water jet (diameter: 25-250 μm) using total internal reflection. Due to the cylindrical jet shape the depth of field increases to above 50 mm, enabling parallel kerfs compared to conventional laser systems. However higher material thicknesses and macro geometries cannot be machined economically viable due to low average laser powers. Fraunhofer IPT has successfully combined a high-power continuous-wave (CW) fiber laser (6 kW) and water jet technology. The main challenge of guiding high-power laser radiation in water is the energy transferred to the jet by absorption, decreasing its stability. A model of laser water interaction in the water jet has been developed and validated experimentally. Based on the results an upscaling of system technology to 30 kW is discussed, enabling a high potential in cutting challenging materials at high qualities and high speeds.

Precision of computer-assisted core decompression drilling of the femoral head.

PubMed

Beckmann, J; Goetz, J; Baethis, H; Kalteis, T; Grifka, J; Perlick, L

2006-08-01

Osteonecrosis of the femoral head is a local destructive disease with progression into devastating stages. Left untreated it mostly leads to severe secondary osteoarthrosis and early endoprosthetic joint replacement. Core decompression by exact drilling into the ischemic areas can be performed in early stages according to Ficat or ARCO. Computer-aided surgery might enhance the precision of the drilling and lower the radiation exposure time of both staff and patients. The aim of this study was to evaluate the precision of the fluoroscopically based VectorVision navigation system in an in vitro model. Thirty sawbones were prepared with a defect filled up with a radiopaque gypsum sphere mimicking the osteonecrosis. Twenty sawbones were drilled by guidance of an intraoperative navigation system VectorVision (BrainLAB, Munich, Germany) and 10 sawbones by fluoroscopic control only. No gypsum sphere was missed. There was a statistically significant difference regarding the three-dimensional deviation (Euclidian norm) as well as maximum deviation in x-, y- or z-direction (maximum norm) to the desired mid-point of the lesion, with a mean of 0.51 and 0.4 mm in the navigated group and 1.1 and 0.88 mm in the control group, respectively. Furthermore, significant difference was found in the number of drilling corrections as well as the radiation time needed: no second drilling or correction of drilling direction was necessary in the navigated group compared to 1.4 in the control group. The radiation time needed was less than 1 s compared to 3.1 s, respectively. The fluoroscopy-based VectorVision navigation system shows a high feasibility of computer-guided drilling with a clear reduction of radiation exposure time and can therefore be integrated into clinical routine. The additional time needed is acceptable regarding the simultaneous reduction of radiation time.

The innate responses of bumble bees to flower patterns: separating the nectar guide from the nectary changes bee movements and search time

NASA Astrophysics Data System (ADS)

Goodale, Eben; Kim, Edward; Nabors, Annika; Henrichon, Sara; Nieh, James C.

2014-06-01

Nectar guides can enhance pollinator efficiency and plant fitness by allowing pollinators to more rapidly find and remember the location of floral nectar. We tested if a radiating nectar guide around a nectary would enhance the ability of naïve bumble bee foragers to find nectar. Most experiments that test nectar guide efficacy, specifically radiating linear guides, have used guides positioned around the center of a radially symmetric flower, where nectaries are often found. However, the flower center may be intrinsically attractive. We therefore used an off-center guide and nectary and compared "conjunct" feeders with a nectar guide surrounding the nectary to "disjunct" feeders with a nectar guide separated from the nectary. We focused on the innate response of novice bee foragers that had never previously visited such feeders. We hypothesized that a disjunct nectar guide would conflict with the visual information provided by the nectary and negatively affect foraging. Approximately, equal numbers of bumble bees ( Bombus impatiens) found nectar on both feeder types. On disjunct feeders, however, unsuccessful foragers spent significantly more time (on average 1.6-fold longer) searching for nectar than any other forager group. Successful foragers on disjunct feeders approached these feeders from random directions unlike successful foragers on conjunct feeders, which preferentially approached the combined nectary and nectar guide. Thus, the nectary and a surrounding nectar guide can be considered a combination of two signals that attract naïve foragers even when not in the floral center.

The innate responses of bumble bees to flower patterns: separating the nectar guide from the nectary changes bee movements and search time.

PubMed

Goodale, Eben; Kim, Edward; Nabors, Annika; Henrichon, Sara; Nieh, James C

2014-06-01

Nectar guides can enhance pollinator efficiency and plant fitness by allowing pollinators to more rapidly find and remember the location of floral nectar. We tested if a radiating nectar guide around a nectary would enhance the ability of naïve bumble bee foragers to find nectar. Most experiments that test nectar guide efficacy, specifically radiating linear guides, have used guides positioned around the center of a radially symmetric flower, where nectaries are often found. However, the flower center may be intrinsically attractive. We therefore used an off-center guide and nectary and compared "conjunct" feeders with a nectar guide surrounding the nectary to "disjunct" feeders with a nectar guide separated from the nectary. We focused on the innate response of novice bee foragers that had never previously visited such feeders. We hypothesized that a disjunct nectar guide would conflict with the visual information provided by the nectary and negatively affect foraging. Approximately, equal numbers of bumble bees (Bombus impatiens) found nectar on both feeder types. On disjunct feeders, however, unsuccessful foragers spent significantly more time (on average 1.6-fold longer) searching for nectar than any other forager group. Successful foragers on disjunct feeders approached these feeders from random directions unlike successful foragers on conjunct feeders, which preferentially approached the combined nectary and nectar guide. Thus, the nectary and a surrounding nectar guide can be considered a combination of two signals that attract naïve foragers even when not in the floral center.

IMAGE-GUIDED TREATMENT USING AN X-RAY THERAPY UNIT AND GOLD NANOPARTICLES: TEST OF CONCEPT.

PubMed

Le Loirec, Cindy; Chambellan, Dominique; Tisseur, David

2016-06-01

Gold nanoparticles (GNPs) have the potential to enhance the radiation dose locally in conjunction with kV X-rays used for radiation therapy. As for other radiotherapy modalities, the absorbed dose needs to be controlled. To do that, it is an advantage to know the distribution of GNPs. However, no effective imaging tool exists to determine the GNP distribution in vivo. Various approaches have been proposed to determine the concentration of GNPs and its distribution in a tumour and in other organs and tissues. X-ray fluorescence computed tomography (XFCT) is a promising imaging technique to do that. A new experimental device based on the XFCT technique allowing the in vivo control of GNP radiotherapy treatments is proposed. As a test of concept, experimental acquisitions and Monte Carlo simulations were performed to determine the performance that a XFCT detector has to fulfil. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Community-based Interventions to Prevent Skin Cancer: Two Community Guide Systematic Reviews

PubMed Central

Sandhu, Paramjit K.; Elder, Randy; Patel, Mona; Saraiya, Mona; Holman, Dawn M.; Perna, Frank; Smith, Robert A.; Buller, David; Sinclair, Craig; Reeder, Anthony; Makin, Jen; McNoe, Bronwen; Glanz, Karen

2016-01-01

Context Skin cancer is a preventable and commonly diagnosed cancer in the U.S. Excessive ultraviolet radiation exposure is a known cause of skin cancer. This article presents updated results of two types of interventions evaluated in a previously published Community Guide systematic review: multicomponent community-wide (MCCW) interventions and mass media (MM) interventions when used alone. Evidence acquisition Studies assessing MCCW and MM interventions to prevent skin cancer by reducing ultraviolet radiation exposure were evaluated using Community Guide systematic review methods. Relevant studies published between 1966 and 2013 were included and analyzed for this review. Evidence synthesis Seven studies evaluating the effectiveness of MCCW interventions showed a median increase in sunscreen use of 10.8 percentage points (interquartile interval=7.3, 23.2); a small decrease in ultraviolet radiation exposure; a decrease in indoor tanning device use of 4.0 percentage points (95% CI=2.5, 5.5); and mixed results for other protective behaviors. Four studies evaluating the effectiveness of MM interventions found that they generally led to improved ultraviolet protection behaviors among children and adults. Conclusions The available evidence showed that MCCW interventions are effective in reducing ultraviolet radiation exposure by increasing sunscreen use. There was, however, insufficient evidence to determine the effectiveness of MM interventions alone in reducing ultraviolet radiation exposure, indicating a continuing need for more research in this field to improve assessment of effectiveness. PMID:27647053

The semiconductor waveguide facet reflectivity problem

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herzinger, C.M.; Lu, C.C.; DeTemple, T.A.

1993-08-01

The problem of the facet reflectivity of a semiconductor slab waveguide is reexamined as an extension of Ikegami's original approach but which includes radiation-like modes. The latter are included, using a guide-within-a-guide geometry, as modes bound to a thick air-cladding guide which contains the core profile of interest. In this model with a relatively simple analysis, the coupling from the fundamental mode to radiation modes can be analyzed. The cross-coupling to the radiation modes is considered in detail for the simple double heterostructure waveguide and is shown to be important only for large core-cladding index differences and for strong modalmore » confinement wherein it results in a true facet loss. The conditions for this are the same as for low threshold lasers so that the loss sets a maximum limit on the equivalent internal quantum efficiency. A separate one-dimensional finite element, numerical mode matching program, which treats evanescent and propagating radiation modes, is used as a comparison. The two methods of accounting for radiation modes are shown to be in good agreement: both predict reduced extremes in reflectivity when compared with the original Ikegami model. Modern graded core cases are treated as general examples along with the specific quantum well laser structures taken from the literature. These include II-VI and III-V structures spanning wavelengths from 0.5 [mu]m to 10.0 [mu]m.« less

Patient-reported Outcome Measurements on the Tolerance of Magnetic Resonance Imaging-guided Radiation Therapy

PubMed Central

Tetar, Shyama; Bakker, Roosje; Jeulink, Marloes; Slotman, Ben J.; Oei, Swie; Haasbeek, Cornelis; De Jong, Karel; Senan, Suresh; Lagerwaard, Frank

2018-01-01

Purpose Magnetic resonance imaging-guided radiation therapy (MRgRT) requires patient positioning within the MR bore and prolonged MR imaging during delivery, both of which are new in radiation oncology. Patient tolerance of MRgRT was prospectively evaluated using patient-reported outcome questionnaires (PRO-Q). Methods Our MRgRT procedure involves daily high-resolution MR scanning, limited re-contouring, daily plan re-optimization, quality assurance (QA), and gated delivery. Patients with claustrophobia are excluded. Mean fraction duration was 45 and 60 minutes for stereotactic treatments during free-breathing and breath-hold, respectively. Patient-controlled video-feedback was used for breath-hold delivery. PRO-Qs collected in the first 150 patients treated included questions on MR-related complaints and also evaluated aspects of active participation. Results Almost one-third of patients (29%) scored at least one PRO-Q item on MR-related complaints as ‘moderate’ or ‘very much’, with noise, feeling cold, and paresthesia being the most frequently scored in this way. Considerable anxiety was reported by 5%, but no medication was required for this in any patient. Patient participation in video feedback for breath-hold delivery was appreciated by the majority of patients, all of whom completed the procedure. Only 5% of patients considered treatment duration to be unacceptably long. Conclusion Despite the lengthy MRgRT procedure, outcomes of PRO-Q indicate that it was well-tolerated by patients. PMID:29719739

TH-F-202-01: MRI Basics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, W.

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

TH-F-202-02: Current Applications of MRI in Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, G.

MRI has excellent soft tissue contrast and can provide both anatomical and physiological information. It is becoming increasingly important in radiation therapy for treatment planning, image-guided radiation therapy, and treatment assessment. It is critically important at this time point to educate and update our medical physicists about MRI to prepare for the upcoming surge of MRI applications in radiation therapy. This session will review important basics of MR physics, pulse sequence designs, and current radiotherapy application, as well as showcase exciting new developments in MRI that can be potentially useful in radiation therapy. Learning Objectives: To learn basics of MRmore » physics and understand the differences between various pulse sequences To review current applications of MRI in radiation therapy.To discuss recent MRI advances for future MRI guided radiation therapy Partly supported by NIH (1R21CA165384).; W. Miller, Research supported in part by Siemens Healthcare; G. Li, My clinical research is in part supported by NIH U54CA137788. I have a collaborative research project with Philips Healthcare.; J. Cai, jing cai.« less

Super-Planckian far-field radiative heat transfer

NASA Astrophysics Data System (ADS)

Fernández-Hurtado, V.; Fernández-Domínguez, A. I.; Feist, J.; García-Vidal, F. J.; Cuevas, J. C.

2018-01-01

We present here a theoretical analysis that demonstrates that the far-field radiative heat transfer between objects with dimensions smaller than the thermal wavelength can overcome the Planckian limit by orders of magnitude. To guide the search for super-Planckian far-field radiative heat transfer, we make use of the theory of fluctuational electrodynamics and derive a relation between the far-field radiative heat transfer and the directional absorption efficiency of the objects involved. Guided by this relation, and making use of state-of-the-art numerical simulations, we show that the far-field radiative heat transfer between highly anisotropic objects can largely overcome the black-body limit when some of their dimensions are smaller than the thermal wavelength. In particular, we illustrate this phenomenon in the case of suspended pads made of polar dielectrics like SiN or SiO2. These structures are widely used to measure the thermal transport through nanowires and low-dimensional systems and can be employed to test our predictions. Our work illustrates the dramatic failure of the classical theory to predict the far-field radiative heat transfer between micro- and nanodevices.

Image-guided positioning and tracking.

PubMed

Ruan, Dan; Kupelian, Patrick; Low, Daniel A

2011-01-01

Radiation therapy aims at maximizing tumor control while minimizing normal tissue complication. The introduction of stereotactic treatment explores the volume effect and achieves dose escalation to tumor target with small margins. The use of ablative irradiation dose and sharp dose gradients requires accurate tumor definition and alignment between patient and treatment geometry. Patient geometry variation during treatment may significantly compromise the conformality of delivered dose and must be managed properly. Setup error and interfraction/intrafraction motion are incorporated in the target definition process by expanding the clinical target volume to planning target volume, whereas the alignment between patient and treatment geometry is obtained with an adaptive control process, by taking immediate actions in response to closely monitored patient geometry. This article focuses on the monitoring and adaptive response aspect of the problem. The term "image" in "image guidance" will be used in a most general sense, to be inclusive of some important point-based monitoring systems that can be considered as degenerate cases of imaging. Image-guided motion adaptive control, as a comprehensive system, involves a hierarchy of decisions, each of which balances simplicity versus flexibility and accuracy versus robustness. Patient specifics and machine specifics at the treatment facility also need to be incorporated into the decision-making process. Identifying operation bottlenecks from a system perspective and making informed compromises are crucial in the proper selection of image-guidance modality, the motion management mechanism, and the respective operation modes. Not intended as an exhaustive exposition, this article focuses on discussing the major issues and development principles for image-guided motion management systems. We hope these information and methodologies will facilitate conscientious practitioners to adopt image-guided motion management systems accounting for patient and institute specifics and to embrace advances in knowledge and new technologies subsequent to the publication of this article.

A current perspective on stereotactic body radiation therapy for pancreatic cancer

PubMed Central

Hong, Julian C; Czito, Brian G; Willett, Christopher G; Palta, Manisha

2016-01-01

Pancreatic cancer is a formidable malignancy with poor outcomes. The majority of patients are unable to undergo resection, which remains the only potentially curative treatment option. The management of locally advanced (unresectable) pancreatic cancer is controversial; however, treatment with either chemotherapy or chemoradiation is associated with high rates of local tumor progression and metastases development, resulting in low survival rates. An emerging local modality is stereotactic body radiation therapy (SBRT), which uses image-guided, conformal, high-dose radiation. SBRT has demonstrated promising local control rates and resultant quality of life with acceptable rates of toxicity. Over the past decade, increasing clinical experience and data have supported SBRT as a local treatment modality. Nevertheless, additional research is required to further evaluate the role of SBRT and improve upon the persistently poor outcomes associated with pancreatic cancer. This review discusses the existing clinical experience and technical implementation of SBRT for pancreatic cancer and highlights the directions for ongoing and future studies. PMID:27826200

A current perspective on stereotactic body radiation therapy for pancreatic cancer.

PubMed

Hong, Julian C; Czito, Brian G; Willett, Christopher G; Palta, Manisha

2016-01-01

Pancreatic cancer is a formidable malignancy with poor outcomes. The majority of patients are unable to undergo resection, which remains the only potentially curative treatment option. The management of locally advanced (unresectable) pancreatic cancer is controversial; however, treatment with either chemotherapy or chemoradiation is associated with high rates of local tumor progression and metastases development, resulting in low survival rates. An emerging local modality is stereotactic body radiation therapy (SBRT), which uses image-guided, conformal, high-dose radiation. SBRT has demonstrated promising local control rates and resultant quality of life with acceptable rates of toxicity. Over the past decade, increasing clinical experience and data have supported SBRT as a local treatment modality. Nevertheless, additional research is required to further evaluate the role of SBRT and improve upon the persistently poor outcomes associated with pancreatic cancer. This review discusses the existing clinical experience and technical implementation of SBRT for pancreatic cancer and highlights the directions for ongoing and future studies.

Radiated noise of ducted fans

NASA Astrophysics Data System (ADS)

Eversman, Walter

The differences in the radiated acoustic fields of ducted and unducted propellers of the same thrust operating under similar conditions are investigated. An FEM model is created for the generation, propagation, and radiation of steady, rotor alone noise and exit guide vane interaction noise of a ducted fan. For a specified number of blades, angular mode harmonic, and rotor angular velocity, the acoustic field is described in a cylindrical coordinate system reduced to only the axial and radial directions. It is found that, contrary to the usual understanding of the Tyler and Sofrin (1962) result, supersonic tip speed rotor noise can be cut off if the tip Mach number is only slightly in excess of unity and if the number of blades is relatively small. If there are many blades, the fundamental angular mode number is large, and the Tyler and Sofrin result for thin annuli becomes more relevant. Shrouding of subsonic tip speed propellers is a very effective means of controlling rotor alone noise.

Base-level management of radio-frequency radiation-protection program. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rademacher, S.E.; Montgomery, N.D.

1989-04-01

AFOEHL developed this report to assist the base-level aerospace medical team manage their radio-frequency radiation-protection program. This report supersedes USAFOEHL Report 80-42, 'A Practical R-F Guide for BEES.'

Base-level management of radio-frequency radiation-protection program. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rademacher, S.E.; Montgomery, N.D.

1989-04-01

AFOEHL developed this report to assist the base-level aerospace medical team manage their radio-frequency radiation protection program. This report supersedes USAFOEHL Report 80-42, 'A practical R-F Guide for BEES.'

Magnetic Resonance Imaging-Guided Adaptive Radiation Therapy: A "Game Changer" for Prostate Treatment?

PubMed

Pathmanathan, Angela U; van As, Nicholas J; Kerkmeijer, Linda G W; Christodouleas, John; Lawton, Colleen A F; Vesprini, Danny; van der Heide, Uulke A; Frank, Steven J; Nill, Simeon; Oelfke, Uwe; van Herk, Marcel; Li, X Allen; Mittauer, Kathryn; Ritter, Mark; Choudhury, Ananya; Tree, Alison C

2018-02-01

Radiation therapy to the prostate involves increasingly sophisticated delivery techniques and changing fractionation schedules. With a low estimated α/β ratio, a larger dose per fraction would be beneficial, with moderate fractionation schedules rapidly becoming a standard of care. The integration of a magnetic resonance imaging (MRI) scanner and linear accelerator allows for accurate soft tissue tracking with the capacity to replan for the anatomy of the day. Extreme hypofractionation schedules become a possibility using the potentially automated steps of autosegmentation, MRI-only workflow, and real-time adaptive planning. The present report reviews the steps involved in hypofractionated adaptive MRI-guided prostate radiation therapy and addresses the challenges for implementation. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

76 FR 35922 - Notice of Issuance of Regulatory Guide

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-20

... CONTACT: Harriet Karagiannis, Regulatory Guide Development Branch, Division of Engineering, Office of... direct the use of individual monitoring devices. In addition, 10 CFR part 34, ``Licenses for Industrial Radiography and Radiation Safety Requirements for Industrial Radiographic Operations,'' includes a specific...

Locoregional Control and Toxicity in Head and Neck Carcinoma Patients following Helical Tomotherapy-Delivered Intensity-Modulated Radiation Therapy Compared with 3D-CRT Data.

PubMed

Santa Cruz, Olalla; Tsoutsou, Pelagia; Castella, Cyril; Khanfir, Kaouthar; Anchisi, Sandro; Bouayed, Salim; Matzinger, Oscar; Ozsahin, Mahmut

2018-06-12

To assess the feasibility and efficacy of intensity-modulated radiation implemented with helical tomotherapy image-guided with daily megavoltage computed tomography for head and neck cancer. Between May 2010 and May 2013, 72 patients were treated with curative intent. The median age was 64 years, with 57% undergoing definitive and 43% postoperative radiotherapy. Primary tumour sites were oral cavity (21%), oropharynx (26%), hypopharynx (20%), larynx (22%), and others (11%). Staging included 4% stage I, 15% II, 26% III, 48% IVa, and 7% IVb. Radiotherapy was combined with chemotherapy in 64%. Primary endpoint was locoregional control, and secondary endpoints survival and toxicity. Median follow-up was 20 months, with 11 locoregional recurrences. Three-year disease-free survival was 58% and overall survival 57%. In the multivariate analysis, age under 64 years, no extracapsular extension, postoperative radiotherapy, induction chemotherapy, and non-oral cavity tumour were significant favourable prognostic factors for disease-free-survival. The overall incidence of acute grade ≥3 toxicities were mucositis 32%, pain 11%, xerostomia 7%, dysphagia 53%, radiodermatitis 44%, and osteonecrosis 1%. Late grade ≥3 toxicities were fibrosis 6%, dysphagia 21%, fistula 1%, and skin necrosis 1%. Intensity-modulated radiation with helical tomotherapy achieved respectable locoregional control and overall survival, with acceptable toxicity, in head and neck cancer patients. © 2018 S. Karger AG, Basel.

MO-FG-BRA-07: Theranostic Gadolinium-Based AGuIX Nanoparticles for MRI-Guided Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Detappe, A; Institut Lumiere-Matiere, Villeurbanne; Nano-H, St-Quentin Fallavier

2015-06-15

Purpose: AGuIX are gadolinium-based nanoparticles, initially developed for MRI, that have a potential role in radiation therapy as a radiosensitizer. Our goal is to demonstrate that these nanoparticles can both be used as an MRI contrast agent, as well as to obtain local dose enhancement in a pancreatic tumor when delivered in combination with an external beam irradiation. Methods: We performed in vitro cell uptake and radiosensitization studies of a pancreatic cancer cell line in a low energy (220kVp) beam, a standard clinical 6MV beam (STD) and a flattening filter free clinical 6MV beam (FFF). After injection of 40mM ofmore » nanoparticles, a biodistribution study was performed in vivo on mice with subcutaneous xenograft pancreatic tumors. In vivo radiation therapy studies were performed at the time point of maximum tumor uptake. Results: The concentration of AGuIX nanoparticles in Panc-1 pancreatic cancer cells, determined in vitro by MRI and ICPMS, peaks after 30 minutes with 0.3% of the initial concentration (5mg/g). Clonogenic assays show a significant effect (p<0.05) when the AGuIX are coupled with MV photon irradiation (DEF20%=1.31). Similar AGuIX tumor uptake is found in vivo by both MRI and ICPMS 30 minutes after intravenous injection. For long term survival studies, the choice of the radiation dose is determined with 5 control groups (3mice/group) irradiated with 0, 5, 10, 15, and 20Gy. Afterwards, 4 groups (8mice/group) are used to evaluate the effect of the nanoparticles. A Logrank test is performed as a statistical test to evaluate the effect of the nanoparticles. Conclusion: The combination of the MRI contrast and radiosensitization properties of gadolinium nanoparticles reveals a strong potential for usage with MRI-guided radiation therapy.« less

ELISA reader does not interfere by mobile phone radiofrequency radiation.

PubMed

Mortazavi, Seyyed Mohammad Javad; Baradaran-Ghahfarokhi, Hamid Reza; Abdi, Mohammad Reza; Baradaran-Ghahfarokhi, Milad; Mostafavi, Nayyer Sadat; Mahmoudi, Golshan; Berenjkoub, Nafiseh; Akmali, Zahra; Hossein-Beigi, Fahimeh; Arsang, Vajiheh

2016-01-01

The increasing number of mobile phones can physically cause electromagnetic interference (EMI) in medical environments; can also cause errors in immunoassays in laboratories. The ELISA readers are widely used as a useful diagnostic tool for Enzymun colorimetric assay in medicine. The aim of this study was to investigate whether the ELISA reader could be interfered by the exposure to the 900 MHz cell phones in the laboratory. Human serum samples were collected from 14 healthy donors (9 women and 5 men) and each sample was divided into four aliquots and was placed into four batches for the in-vitro quantitative determination of human chorionic gonadotropin (hCG). During colorimetric reading of the first, second, and third batches, the ELISA reader (Stat Fax 2100, Awareness Technology, Inc., USA) was exposed to 0.5, 1.0, and 2.0 W exposure of 900 MHz radiation, respectively. For the forth batch (control group), no radiation was applied. All experiments were performed comparing ELISA read out results of the I, II, and III batches with the control batch, using the Wilcoxon test with criterion level of P = 0.050. The final scores in the exposed batches I, II, and III were not statistically significant relative to the control batch (P > 0.05). The results showed that 900 MHz radiation exposure did not alter the ELISA measured levels of hCG hormone in I (P = 0.219), II (P = 0.909), and III (P = 0.056) batches compared to the control batch. This study showed that ELISA reader does not interfere by mobile phone RF radiation at a closed contact (less than 5 cm distance). However, we recommend that medical institutions discuss these issues in the context of their specific use of technologies and frame a policy that is clear and straightforward to guide staff, patients, and visitors.

ELISA reader does not interfere by mobile phone radiofrequency radiation

PubMed Central

Mortazavi, Seyyed Mohammad Javad; Baradaran-Ghahfarokhi, Hamid Reza; Abdi, Mohammad Reza; Baradaran-Ghahfarokhi, Milad; Mostafavi, Nayyer Sadat; Mahmoudi, Golshan; Berenjkoub, Nafiseh; Akmali, Zahra; Hossein-Beigi, Fahimeh; Arsang, Vajiheh

2016-01-01

Background: The increasing number of mobile phones can physically cause electromagnetic interference (EMI) in medical environments; can also cause errors in immunoassays in laboratories. The ELISA readers are widely used as a useful diagnostic tool for Enzymun colorimetric assay in medicine. The aim of this study was to investigate whether the ELISA reader could be interfered by the exposure to the 900 MHz cell phones in the laboratory. Materials and Methods: Human serum samples were collected from 14 healthy donors (9 women and 5 men) and each sample was divided into four aliquots and was placed into four batches for the in-vitro quantitative determination of human chorionic gonadotropin (hCG). During colorimetric reading of the first, second, and third batches, the ELISA reader (Stat Fax 2100, Awareness Technology, Inc., USA) was exposed to 0.5, 1.0, and 2.0 W exposure of 900 MHz radiation, respectively. For the forth batch (control group), no radiation was applied. All experiments were performed comparing ELISA read out results of the I, II, and III batches with the control batch, using the Wilcoxon test with criterion level of P = 0.050. Results: The final scores in the exposed batches I, II, and III were not statistically significant relative to the control batch (P > 0.05). The results showed that 900 MHz radiation exposure did not alter the ELISA measured levels of hCG hormone in I (P = 0.219), II (P = 0.909), and III (P = 0.056) batches compared to the control batch. Conclusion: This study showed that ELISA reader does not interfere by mobile phone RF radiation at a closed contact (less than 5 cm distance). However, we recommend that medical institutions discuss these issues in the context of their specific use of technologies and frame a policy that is clear and straightforward to guide staff, patients, and visitors. PMID:27376040

Continued Benefit to Rectal Separation for Prostate Radiation Therapy: Final Results of a Phase III Trial

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hamstra, Daniel A., E-mail: Daniel.Hamstra@gmail.com; Mariados, Neil; Sylvester, John

Purpose: SpaceOAR, a Food and Drug Administration–approved hydrogel intended to create a rectal–prostate space, was evaluated in a single-blind phase III trial of image guided intensity modulated radiation therapy. A total of 222 men were randomized 2:1 to the spacer or control group and received 79.2 Gy in 1.8-Gy fractions to the prostate with or without the seminal vesicles. The present study reports the final results with a median follow-up period of 3 years. Methods and Materials: Cumulative (Common Terminology Criteria for Adverse Events, version 4.0) toxicity was evaluated using the log-rank test. Quality of life (QOL) was examined using the Expandedmore » Prostate Cancer Index Composite (EPIC), and the mean changes from baseline in the EPIC domains were tested using repeated measures models. The proportions of men with minimally important differences (MIDs) in each domain were tested using repeated measures logistic models with prespecified thresholds. Results: The 3-year incidence of grade ≥1 (9.2% vs 2.0%; P=.028) and grade ≥2 (5.7% vs 0%; P=.012) rectal toxicity favored the spacer arm. Grade ≥1 urinary incontinence was also lower in the spacer arm (15% vs 4%; P=.046), with no difference in grade ≥2 urinary toxicity (7% vs 7%; P=0.7). From 6 months onward, bowel QOL consistently favored the spacer group (P=.002), with the difference at 3 years (5.8 points; P<.05) meeting the threshold for a MID. The control group had a 3.9-point greater decline in urinary QOL compared with the spacer group at 3 years (P<.05), but the difference did not meet the MID threshold. At 3 years, more men in the control group than in the spacer group had experienced a MID decline in bowel QOL (41% vs 14%; P=.002) and urinary QOL (30% vs 17%; P=.04). Furthermore, the control group were also more likely to have experienced large declines (twice the MID) in bowel QOL (21% vs 5%; P=.02) and urinary QOL (23% vs 8%; P=.02). Conclusions: The benefit of a hydrogel spacer in reducing the rectal dose, toxicity, and QOL declines after image guided intensity modulated radiation therapy for prostate cancer was maintained or increased with a longer follow-up period, providing stronger evidence for the benefit of hydrogel spacer use in prostate radiation therapy.« less

Continued Benefit to Rectal Separation for Prostate Radiation Therapy: Final Results of a Phase III Trial.

PubMed

Hamstra, Daniel A; Mariados, Neil; Sylvester, John; Shah, Dhiren; Karsh, Lawrence; Hudes, Richard; Beyer, David; Kurtzman, Steven; Bogart, Jeffrey; Hsi, R Alex; Kos, Michael; Ellis, Rodney; Logsdon, Mark; Zimberg, Shawn; Forsythe, Kevin; Zhang, Hong; Soffen, Edward; Francke, Patrick; Mantz, Constantine; Rossi, Peter; DeWeese, Theodore; Daignault-Newton, Stephanie; Fischer-Valuck, Benjamin W; Chundury, Anupama; Gay, Hiram; Bosch, Walter; Michalski, Jeff

2017-04-01

SpaceOAR, a Food and Drug Administration-approved hydrogel intended to create a rectal-prostate space, was evaluated in a single-blind phase III trial of image guided intensity modulated radiation therapy. A total of 222 men were randomized 2:1 to the spacer or control group and received 79.2 Gy in 1.8-Gy fractions to the prostate with or without the seminal vesicles. The present study reports the final results with a median follow-up period of 3 years. Cumulative (Common Terminology Criteria for Adverse Events, version 4.0) toxicity was evaluated using the log-rank test. Quality of life (QOL) was examined using the Expanded Prostate Cancer Index Composite (EPIC), and the mean changes from baseline in the EPIC domains were tested using repeated measures models. The proportions of men with minimally important differences (MIDs) in each domain were tested using repeated measures logistic models with prespecified thresholds. The 3-year incidence of grade ≥1 (9.2% vs 2.0%; P=.028) and grade ≥2 (5.7% vs 0%; P=.012) rectal toxicity favored the spacer arm. Grade ≥1 urinary incontinence was also lower in the spacer arm (15% vs 4%; P=.046), with no difference in grade ≥2 urinary toxicity (7% vs 7%; P=0.7). From 6 months onward, bowel QOL consistently favored the spacer group (P=.002), with the difference at 3 years (5.8 points; P<.05) meeting the threshold for a MID. The control group had a 3.9-point greater decline in urinary QOL compared with the spacer group at 3 years (P<.05), but the difference did not meet the MID threshold. At 3 years, more men in the control group than in the spacer group had experienced a MID decline in bowel QOL (41% vs 14%; P=.002) and urinary QOL (30% vs 17%; P=.04). Furthermore, the control group were also more likely to have experienced large declines (twice the MID) in bowel QOL (21% vs 5%; P=.02) and urinary QOL (23% vs 8%; P=.02). The benefit of a hydrogel spacer in reducing the rectal dose, toxicity, and QOL declines after image guided intensity modulated radiation therapy for prostate cancer was maintained or increased with a longer follow-up period, providing stronger evidence for the benefit of hydrogel spacer use in prostate radiation therapy. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Localization accuracy from automatic and semi-automatic rigid registration of locally-advanced lung cancer targets during image-guided radiation therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robertson, Scott P.; Weiss, Elisabeth; Hugo, Geoffrey D.

2012-01-15

Purpose: To evaluate localization accuracy resulting from rigid registration of locally-advanced lung cancer targets using fully automatic and semi-automatic protocols for image-guided radiation therapy. Methods: Seventeen lung cancer patients, fourteen also presenting with involved lymph nodes, received computed tomography (CT) scans once per week throughout treatment under active breathing control. A physician contoured both lung and lymph node targets for all weekly scans. Various automatic and semi-automatic rigid registration techniques were then performed for both individual and simultaneous alignments of the primary gross tumor volume (GTV{sub P}) and involved lymph nodes (GTV{sub LN}) to simulate the localization process in image-guidedmore » radiation therapy. Techniques included ''standard'' (direct registration of weekly images to a planning CT), ''seeded'' (manual prealignment of targets to guide standard registration), ''transitive-based'' (alignment of pretreatment and planning CTs through one or more intermediate images), and ''rereferenced'' (designation of a new reference image for registration). Localization error (LE) was assessed as the residual centroid and border distances between targets from planning and weekly CTs after registration. Results: Initial bony alignment resulted in centroid LE of 7.3 {+-} 5.4 mm and 5.4 {+-} 3.4 mm for the GTV{sub P} and GTV{sub LN}, respectively. Compared to bony alignment, transitive-based and seeded registrations significantly reduced GTV{sub P} centroid LE to 4.7 {+-} 3.7 mm (p = 0.011) and 4.3 {+-} 2.5 mm (p < 1 x 10{sup -3}), respectively, but the smallest GTV{sub P} LE of 2.4 {+-} 2.1 mm was provided by rereferenced registration (p < 1 x 10{sup -6}). Standard registration significantly reduced GTV{sub LN} centroid LE to 3.2 {+-} 2.5 mm (p < 1 x 10{sup -3}) compared to bony alignment, with little additional gain offered by the other registration techniques. For simultaneous target alignment, centroid LE as low as 3.9 {+-} 2.7 mm and 3.8 {+-} 2.3 mm were achieved for the GTV{sub P} and GTV{sub LN}, respectively, using rereferenced registration. Conclusions: Target shape, volume, and configuration changes during radiation therapy limited the accuracy of standard rigid registration for image-guided localization in locally-advanced lung cancer. Significant error reductions were possible using other rigid registration techniques, with LE approaching the lower limit imposed by interfraction target variability throughout treatment.« less

Challenges and opportunities in patient-specific, motion-managed and PET/CT-guided radiation therapy of lung cancer: review and perspective

PubMed Central

2012-01-01

The increasing interest in combined positron emission tomography (PET) and computed tomography (CT) to guide lung cancer radiation therapy planning has been well documented. Motion management strategies during treatment simulation PET/CT imaging and treatment delivery have been proposed to improve the precision and accuracy of radiotherapy. In light of these research advances, why has translation of motion-managed PET/CT to clinical radiotherapy been slow and infrequent? Solutions to this problem are as complex as they are numerous, driven by large inter-patient variability in tumor motion trajectories across a highly heterogeneous population. Such variation dictates a comprehensive and patient-specific incorporation of motion management strategies into PET/CT-guided radiotherapy rather than a one-size-fits-all tactic. This review summarizes challenges and opportunities for clinical translation of advances in PET/CT-guided radiotherapy, as well as in respiratory motion-managed radiotherapy of lung cancer. These two concepts are then integrated into proposed patient-specific workflows that span classification schemes, PET/CT image formation, treatment planning, and adaptive image-guided radiotherapy delivery techniques. PMID:23369522

How Does Patient Radiation Exposure Compare With Low-dose O-arm Versus Fluoroscopy for Pedicle Screw Placement in Idiopathic Scoliosis?

PubMed

Su, Alvin W; McIntosh, Amy L; Schueler, Beth A; Milbrandt, Todd A; Winkler, Jennifer A; Stans, Anthony A; Larson, A Noelle

Intraoperative C-arm fluoroscopy and low-dose O-arm are both reasonable means to assist in screw placement for idiopathic scoliosis surgery. Both using pediatric low-dose O-arm settings and minimizing the number of radiographs during C-arm fluoroscopy guidance decrease patient radiation exposure and its deleterious biological effect that may be associated with cancer risk. We hypothesized that the radiation dose for C-arm-guided fluoroscopy is no less than low-dose O-arm scanning for placement of pedicle screws. A multicenter matched-control cohort study of 28 patients in total was conducted. Fourteen patients who underwent O-arm-guided pedicle screw insertion for spinal fusion surgery in 1 institution were matched to another 14 patients who underwent C-arm fluoroscopy guidance in the other institution in terms of the age of surgery, body weight, and number of imaged spine levels. The total effective dose was compared. A low-dose pediatric protocol was used for all O-arm scans with an effective dose of 0.65 mSv per scan. The effective dose of C-arm fluoroscopy was determined using anthropomorphic phantoms that represented the thoracic and lumbar spine in anteroposterior and lateral views, respectively. The clinical outcome and complications of all patients were documented. The mean total effective dose for the O-arm group was approximately 4 times higher than that of the C-arm group (P<0.0001). The effective dose for the C-arm patients had high variability based on fluoroscopy time and did not correlate with the number of imaged spine levels or body weight. The effective dose of 1 low-dose pediatric O-arm scan approximated 85 seconds of the C-arm fluoroscopy time. All patients had satisfactory clinical outcomes without major complications that required returning to the operating room. Radiation exposure required for O-arm scans can be higher than that required for C-arm fluoroscopy, but it depends on fluoroscopy time. Inclusion of more medical centers and surgeons will better account for the variability of C-arm dose due to distinct patient characteristics, surgeon's preference, and individual institution's protocol. Level III-case-control study.

Electromagnetic-Guided MLC Tracking Radiation Therapy for Prostate Cancer Patients: Prospective Clinical Trial Results.

PubMed

Keall, Paul J; Colvill, Emma; O'Brien, Ricky; Caillet, Vincent; Eade, Thomas; Kneebone, Andrew; Hruby, George; Poulsen, Per R; Zwan, Benjamin; Greer, Peter B; Booth, Jeremy

2018-06-01

To report on the primary and secondary outcomes of a prospective clinical trial of electromagnetic-guided multileaf collimator (MLC) tracking radiation therapy for prostate cancer. Twenty-eight men with prostate cancer were treated with electromagnetic-guided MLC tracking with volumetric modulated arc therapy. A total of 858 fractions were delivered, with the dose per fraction ranging from 2 to 13.75 Gy. The primary outcome was feasibility, with success determined if >95% of fractions were successfully delivered. The secondary outcomes were (1) the improvement in beam-target geometric alignment, (2) the improvement in dosimetric coverage of the prostate and avoidance of critical structures, and (3) no acute grade ≥3 genitourinary or gastrointestinal toxicity. All 858 planned fractions were successfully delivered with MLC tracking, demonstrating the primary outcome of feasibility (P < .001). MLC tracking improved the beam-target geometric alignment from 1.4 to 0.90 mm (root-mean-square error). MLC tracking improved the dosimetric coverage of the prostate and reduced the daily variation in dose to critical structures. No acute grade ≥3 genitourinary or gastrointestinal toxicity was observed. Electromagnetic-guided MLC tracking radiation therapy for prostate cancer is feasible. The patients received improved geometric targeting and delivered dose distributions that were closer to those planned than they would have received without electromagnetic-guided MLC tracking. No significant acute toxicity was observed. Copyright © 2018 Elsevier Inc. All rights reserved.

Dosimetric analysis of stereotactic body radiation therapy for pancreatic cancer using MR-guided Tri-60Co unit, MR-guided LINAC, and conventional LINAC-based plans.

PubMed

Ramey, Stephen James; Padgett, Kyle R; Lamichhane, Narottam; Neboori, Hanmath J; Kwon, Deukwoo; Mellon, Eric A; Brown, Karen; Duffy, Melissa; Victoria, James; Dogan, Nesrin; Portelance, Lorraine

2018-03-01

This study aims to perform a dosimetric comparison of 2 magnetic resonance (MR)-guided radiation therapy systems capable of performing online adaptive radiation therapy versus a conventional radiation therapy system for pancreas stereotactic body radiation therapy. Ten cases of patients with pancreatic adenocarcinoma previously treated in our institution were used for this analysis. MR-guided tri-cobalt 60 therapy (MR-cobalt) and MR-LINAC plans were generated and compared with conventional LINAC (volumetric modulated arc therapy) plans. The prescription dose was 40 Gy in 5 fractions covering 95% of the planning tumor volume for the 30 plans. The same organs at risk (OARs) dose constraints were used in all plans. Dose-volume-based indices were used to compare PTV coverage and OAR sparing. The conformity index of 40 Gy in 5 fractions covering 95% of the planning tumor volume demonstrated higher conformity in both LINAC-based plans compared with MR-cobalt plans. Although there was no difference in mean conformity index between LINAC and MR-LINAC plans (1.08 in both), there was a large difference between LINAC and MR-cobalt plans (1.08 vs 1.52). Overall, 79%, 72%, and 78% of critical structure dosimetric constraints were met with LINAC, MR-cobalt, and MR-LINAC plans, respectively. The MR-cobalt plans delivered more doses to all OARs compared with the LINAC plans. In contrast, the doses to the OARs of the MR-LINAC plans were similar to LINAC plans except in 2 cases: liver mean dose (MR-LINAC, 2 .8 Gy vs LINAC, 2.1 Gy) and volume of duodenum receiving at least 15 Gy (MR-LINAC, 13.2 mL vs LINAC, 15.4 mL). Both differences are likely not clinically significant. This study demonstrates that dosimetrically similar plans were achieved with conventional LINAC and MR-LINAC, whereas doses to OARs were statistically higher for MR-cobalt compared with conventional LINAC plans because of low-dose spillage. Given the improved tumor-tracking capabilities of MR-LINAC, further studies should evaluate potential benefits of adaptive radiation therapy-capable MR-guided LINAC treatment. Copyright © 2018. Published by Elsevier Inc.

BEIR-III controverly

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fabrikant, J.I.

1980-06-01

How certain of the areas addressed by the Committee on the Biological Effects of Ionizing Radiation (BEIR) have attempted to deal with the scientific basis for establishing appropriate radiation protection guides is discussed, and what effect this may have on decision-making for the regulation of societal activities concerned with the health effects in human populations exposed to low-level radiation. (ACR)

Clinical trial tests precision radiotherapy for recurrent prostate cancer | Center for Cancer Research

Cancer.gov

CCR investigators are leading a trial of stereotactic body radiation therapy (SBRT) to treat localized prostate cancer that has recurred after standard radiation therapy. The technique uses advanced molecular imaging to guide the delivery of high doses of radiation just to tumors that have recurred, potentially leading to fewer side effects. Read more…

Comparison of visual biofeedback system with a guiding waveform and abdomen-chest motion self-control system for respiratory motion management.

PubMed

Nakajima, Yujiro; Kadoya, Noriyuki; Kanai, Takayuki; Ito, Kengo; Sato, Kiyokazu; Dobashi, Suguru; Yamamoto, Takaya; Ishikawa, Yojiro; Matsushita, Haruo; Takeda, Ken; Jingu, Keiichi

2016-07-01

Irregular breathing can influence the outcome of 4D computed tomography imaging and cause artifacts. Visual biofeedback systems associated with a patient-specific guiding waveform are known to reduce respiratory irregularities. In Japan, abdomen and chest motion self-control devices (Abches) (representing simpler visual coaching techniques without a guiding waveform) are used instead; however, no studies have compared these two systems to date. Here, we evaluate the effectiveness of respiratory coaching in reducing respiratory irregularities by comparing two respiratory management systems. We collected data from 11 healthy volunteers. Bar and wave models were used as visual biofeedback systems. Abches consisted of a respiratory indicator indicating the end of each expiration and inspiration motion. Respiratory variations were quantified as root mean squared error (RMSE) of displacement and period of breathing cycles. All coaching techniques improved respiratory variation, compared with free-breathing. Displacement RMSEs were 1.43 ± 0.84, 1.22 ± 1.13, 1.21 ± 0.86 and 0.98 ± 0.47 mm for free-breathing, Abches, bar model and wave model, respectively. Period RMSEs were 0.48 ± 0.42, 0.33 ± 0.31, 0.23 ± 0.18 and 0.17 ± 0.05 s for free-breathing, Abches, bar model and wave model, respectively. The average reduction in displacement and period RMSE compared with the wave model were 27% and 47%, respectively. For variation in both displacement and period, wave model was superior to the other techniques. Our results showed that visual biofeedback combined with a wave model could potentially provide clinical benefits in respiratory management, although all techniques were able to reduce respiratory irregularities. © The Author 2016. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.

Breathing-motion-compensated robotic guided stereotactic body radiation therapy : Patterns of failure analysis.

PubMed

Stera, Susanne; Balermpas, Panagiotis; Chan, Mark K H; Huttenlocher, Stefan; Wurster, Stefan; Keller, Christian; Imhoff, Detlef; Rades, Dirk; Dunst, Jürgen; Rödel, Claus; Hildebrandt, Guido; Blanck, Oliver

2018-02-01

We retrospectively evaluated the patterns of failure for robotic guided real-time breathing-motion-compensated (BMC) stereotactic body radiation therapy (SBRT) in the treatment of tumors in moving organs. Between 2011 and 2016, a total of 198 patients with 280 lung, liver, and abdominal tumors were treated with BMC-SBRT. The median gross tumor volume (GTV) was 12.3 cc (0.1-372.0 cc). Medians of mean GTV BED α/β = 10   Gy (BED = biological effective dose) was 148.5 Gy 10 (31.5-233.3 Gy 10 ) and prescribed planning target volume (PTV) BED α/β = 10   Gy was 89.7 Gy 10 (28.8-151.2 Gy 10 ), respectively. We analyzed overall survival (OS) and local control (LC) based on various factors, including BEDs with α/β ratios of 15 Gy (lung metastases), 21 Gy (primary lung tumors), and 27 Gy (liver metastases). Median follow-up was 10.4 months (2.0-59.0 months). The 2‑year actuarial LC was 100 and 86.4% for primary early and advanced stage lung tumors, respectively, 100% for lung metastases, 82.2% for liver metastases, and 90% for extrapulmonary extrahepatic metastases. The 2‑year OS rate was 47.9% for all patients. In uni- and multivariate analysis, comparatively lower PTV prescription dose (equivalence of 3 × 12-13 Gy) and higher average GTV dose (equivalence of 3 × 18 Gy) to current practice were significantly associated with LC. For OS, Karnofsky performance score (100%), gender (female), and SBRT without simultaneous chemotherapy were significant prognostic factors. Grade 3 side effects were rare (0.5%). Robotic guided BMC-SBRT can be considered a safe and effective treatment for solid tumors in moving organs. To reach sufficient local control rates, high average GTV doses are necessary. Further prospective studies are warranted to evaluate these points.

A Case Report of Salvage Radiotherapy for a Patient with Recurrent Gastric Cancer and Multiple Comorbidities Using Real-time MRI-guided Adaptive Treatment System

PubMed Central

Jeon, Seung Hyuck; Chie, Eui Kyu

2018-01-01

The stomach is one of the most deforming organs caused by respiratory motions and daily variation by food intake. Applying radiotherapy has been quite a challenge due to the high risk of missing the target as well as radiation exposure to large volumes of normal tissue. However, real-time magnetic resonance (MR)-guided radiotherapy with adaptive planning could focus the high dose radiation to the target area while minimizing neighboring normal tissue exposure and compensate for not only daily but real-time variation. Here is a case report of a patient with recurrent gastric cancer and multiple co-morbidities, unsuitable for both resection and chemotherapy, who underwent MR guided adaptive radiotherapy. PMID:29900091

Utility of Intravascular US-Guided Portal Vein Access during Transjugular Intrahepatic Portosystemic Shunt Creation: Retrospective Comparison with Conventional Technique in 109 Patients.

PubMed

Pillai, Anil K; Andring, Brice; Faulconer, Nicholas; Reis, Stephen P; Xi, Yin; Iyamu, Ikponmwosa; Suthpin, Patrick D; Kalva, Sanjeeva P

2016-08-01

To compare safety and effectiveness of intravascular ultrasound (US)-guided portal vein access during transjugular intrahepatic portosystemic shunt (TIPS) creation with conventional TIPS technique. In this retrospective study, TIPS creation using intravascular US guidance in 55 patients was compared with conventional TIPS creation in 54 patients by 10 operators over a 3-year period. Operators were classified as experienced if they had performed ≥ 20 TIPS procedures at the beginning of the study period. Time to portal vein access, total radiation dose, and needle pass-related capsular perforation were recorded. Baseline demographic characteristics of patients were similar (P > .05). Mean time to portal venous access was 46 minutes ± 37 for conventional TIPS and 31 minutes ± 19 for intravascular US-guided TIPS (P = .007). Intravascular US guidance allowed significantly shorter times (48 min ± 30 vs 28 min ± 16; P = .01) to portal vein access among operators (n = 5) with limited experience but failed to achieve any significant time savings (44 min ± 43 vs 34 min ± 22; P = .89) among experienced operators (n = 5). Needle pass-related capsular perforation occurred in 17/54 (34%) patients with conventional TIPS and 5/55 (9%) patients with intravascular US-guided TIPS (P = .004). Radiation dose was 2,376 mGy ± 1,816 for conventional TIPS and 1,592 mGy ± 1,263 for intravascular US-guided TIPS (P = .004). Intravascular US-guided portal vein access during TIPS creation is associated with shorter portal vein access times, decreased needle pass-related capsular perforations, and reduced radiation dose. Copyright © 2016 SIR. Published by Elsevier Inc. All rights reserved.

Optical and terahertz energy concentration on the nanoscale in plasmonics

NASA Astrophysics Data System (ADS)

Rusina, Anastasia

We introduce an approach to implement full coherent control on nanometer length scales. It is based on spatiotemporal modulation of the surface plasmon polariton (SPP) fields at the thick edge of a nanowedge. The SPP wavepackets propagating toward the sharp edge of this nanowedge are compressed and adiabatically concentrated at a nanofocus, forming an ultrashort pulse of local fields. The profile of the focused waveform as a function of time and one spatial dimension is completely coherently controlled. We establish the principal limits for the nanoconcentration of the terahertz (THz) radiation in metal/dielectric waveguides and determine their optimum shapes required for this nanoconcentration. We predict that the adiabatic compression of THz radiation from the initial spot size of vacuum wavelength R0 ≈ lambda0 ≈ 300 microm to the unprecedented final size of R = 100--250 nm can be achieved, while the THz radiation intensity is increased by a factor of 10 to 250. This THz energy nanoconcentration will not only improve the spatial resolution and increase the signal/noise ratio for THz imaging and spectroscopy, but in combination with the recently developed sources of powerful THz pulses, will allow the observation of nonlinear THz effects and a variety of nonlinear spectroscopies (such as two-dimensional spectroscopy), which are highly informative. This should find a wide spectrum of applications in science, engineering, biomedical research and environmental monitoring. We also develop a theory of the spoof plasmons propagating at the interface between a dielectric and a real conductor. The deviation from a perfect conductor is introduced through a finite skin depth. The possibilities of guiding and focusing of spoof plasmons are considered. Geometrical parameters of the structure are found which provide a good guiding of such modes. Moreover, the limit on the concentration by means of planar spoof plasmons in case of non-ideal metal is established. These properties of spoof plasmons are of great interest for THz technology. INDEX WORDS: Nanoplasmonics, Surface plasmon polaritons, Adiabatic concentration, Full coherent control on nanoscale, Nanowedge, Terahertz, Coaxial waveguide, Spoof plasmons, Nanoscale, Nanofocus, Terahertz (THz) energy nanoconcentration

WE-G-12A-01: High Intensity Focused Ultrasound Surgery and Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farahani, K; O'Neill, B

More and more emphasis is being made on alternatives to invasive surgery and the use of ionizing radiation to treat various diseases including cancer. Novel screening, diagnosis, treatment and monitoring of response to treatment are also hot areas of research and new clinical technologies. Ultrasound(US) has gained traction in all of the aforementioned areas of focus. Especially with recent advances in the use of ultrasound to noninvasively treat various diseases/organ systems. This session will focus on covering MR-guided focused ultrasound and the state of the art clinical applications, and the second speaker will survey the more cutting edge technologies e.g.more » Focused Ultrasound (FUS) mediated drug delivery, principles of cavitation and US guided FUS. Learning Objectives: Fundamental physics and physical limitations of US interaction with tissue and nanoparticles The alteration of tissue transport using focused ultrasound US control of nanoparticle drug carriers for targeted release The basic principles of MRI-guided focused ultrasound (MRgFUS) surgery and therapy the current state of the art clinical applications of MRgFUS requirements for quality assurance and treatment planning.« less

Detecting pin diversion from pressurized water reactors spent fuel assemblies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ham, Young S.; Sitaraman, Shivakumar

Detecting diversion of spent fuel from Pressurized Water Reactors (PWR) by determining possible diversion including the steps of providing a detector cluster containing gamma ray and neutron detectors, inserting the detector cluster containing the gamma ray and neutron detectors into the spent fuel assembly through the guide tube holes in the spent fuel assembly, measuring gamma ray and neutron radiation responses of the gamma ray and neutron detectors in the guide tube holes, processing the gamma ray and neutron radiation responses at the guide tube locations by normalizing them to the maximum value among each set of responses and takingmore » the ratio of the gamma ray and neutron responses at the guide tube locations and normalizing the ratios to the maximum value among them and producing three signatures, gamma, neutron, and gamma-neutron ratio, based on these normalized values, and producing an output that consists of these signatures that can indicate possible diversion of the pins from the spent fuel assembly.« less

MRI-Guided High–Dose-Rate Intracavitary Brachytherapy for Treatment of Cervical Cancer: The University of Pittsburgh Experience

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gill, Beant S.; Kim, Hayeon; Houser, Christopher J.

2015-03-01

Purpose: Image-based brachytherapy is increasingly used for gynecologic malignancies. We report early outcomes of magnetic resonance imaging (MRI)-guided brachytherapy. Methods and Materials: Consecutive patient cases with FIGO stage IB1 to IVA cervical cancer treated at a single institution were retrospectively reviewed. All patients received concurrent cisplatin with external beam radiation therapy along with interdigitated high–dose-rate intracavitary brachytherapy. Computed tomography or MRI was completed after each application, the latter acquired for at least 1 fraction. High-risk clinical target volume (HRCTV) and organs at risk were identified by Groupe Européen de Curiethérapie and European SocieTy for Radiotherapy and Oncology guidelines. Doses weremore » converted to equivalent 2-Gy doses (EQD{sub 2}) with planned HRCTV doses of 75 to 85 Gy. Results: From 2007 to 2013, 128 patients, median 52 years of age, were treated. Predominant characteristics included stage IIB disease (58.6%) with a median tumor size of 5 cm, squamous histology (82.8%), and no radiographic nodal involvement (53.1%). Most patients (67.2%) received intensity modulated radiation therapy (IMRT) at a median dose of 45 Gy, followed by a median brachytherapy dose of 27.5 Gy (range, 25-30 Gy) in 5 fractions. At a median follow up of 24.4 months (range, 2.1-77.2 months), estimated 2-year local control, disease-free survival, and cancer-specific survival rates were 91.6%, 81.8%, and 87.6%, respectively. Predictors of local failure included adenocarcinoma histology (P<.01) and clinical response at 3 months (P<.01). Among the adenocarcinoma subset, receiving HRCTV D{sub 90} EQD{sub 2} ≥84 Gy was associated with improved local control (2-year local control rate 100% vs 54.5%, P=.03). Grade 3 or greater gastrointestinal or genitourinary late toxicity occurred at a 2-year actuarial rate of 0.9%. Conclusions: This study constitutes one of the largest reported series of MRI-guided brachytherapy in North America, demonstrating excellent local control with acceptable morbidity. Dose escalation may be warranted when feasible for adenocarcinomas to offset the risk of local failure.« less

Dosimetric and radiobiological consequences of computed tomography-guided adaptive strategies for intensity modulated radiation therapy of the prostate.

PubMed

Battista, Jerry J; Johnson, Carol; Turnbull, David; Kempe, Jeff; Bzdusek, Karl; Van Dyk, Jacob; Bauman, Glenn

2013-12-01

To examine a range of scenarios for image-guided adaptive radiation therapy of prostate cancer, including different schedules for megavoltage CT imaging, patient repositioning, and dose replanning. We simulated multifraction dose distributions with deformable registration using 35 sets of megavoltage CT scans of 13 patients. We computed cumulative dose-volume histograms, from which tumor control probabilities and normal tissue complication probabilities (NTCPs) for rectum were calculated. Five-field intensity modulated radiation therapy (IMRT) with 18-MV x-rays was planned to achieve an isocentric dose of 76 Gy to the clinical target volume (CTV). The differences between D95, tumor control probability, V70Gy, and NTCP for rectum, for accumulated versus planned dose distributions, were compared for different target volume sizes, margins, and adaptive strategies. The CTV D95 for IMRT treatment plans, averaged over 13 patients, was 75.2 Gy. Using the largest CTV margins (10/7 mm), the D95 values accumulated over 35 fractions were within 2% of the planned value, regardless of the adaptive strategy used. For tighter margins (5 mm), the average D95 values dropped to approximately 73.0 Gy even with frequent repositioning, and daily replanning was necessary to correct this deficit. When personalized margins were applied to an adaptive CTV derived from the first 6 treatment fractions using the STAPLE (Simultaneous Truth and Performance Level Estimation) algorithm, target coverage could be maintained using a single replan 1 week into therapy. For all approaches, normal tissue parameters (rectum V(70Gy) and NTCP) remained within acceptable limits. The frequency of adaptive interventions depends on the size of the CTV combined with target margins used during IMRT optimization. The application of adaptive target margins (<5 mm) to an adaptive CTV determined 1 week into therapy minimizes the need for subsequent dose replanning. Copyright © 2013 Elsevier Inc. All rights reserved.

Multifractionated image-guided and stereotactic intensity-modulated radiotherapy of paraspinal tumors: a preliminary report.

PubMed

Yamada, Yoshiya; Lovelock, D Michael; Yenice, Kamil M; Bilsky, Mark H; Hunt, Margaret A; Zatcky, Joan; Leibel, Steven A

2005-05-01

The use of image-guided and stereotactic intensity-modulated radiotherapy (IMRT) techniques have made the delivery of high-dose radiation to lesions within close proximity to the spinal cord feasible. This report presents clinical and physical data regarding the use of IMRT coupled with noninvasive body frames (stereotactic and image-guided) for multifractionated radiotherapy. The Memorial Sloan-Kettering Cancer Center (Memorial) stereotactic body frame (MSBF) and Memorial body cradle (MBC) have been developed as noninvasive immobilizing devices for paraspinal IMRT using stereotactic (MSBF) and image-guided (MBC) techniques. Patients were either previously irradiated or prescribed doses beyond spinal cord tolerance (54 Gy in standard fractionation) and had unresectable gross disease involving the spinal canal. The planning target volume (PTV) was the gross tumor volume with a 1 cm margin. The PTV was not allowed to include the spinal cord contour. All treatment planning was performed using software developed within the institution. Isocenter verification was performed with an in-room computed tomography scan (MSBF) or electronic portal imaging devices, or both. Patients were followed up with serial magnetic resonance imaging every 3-4 months, and no patients were lost to follow-up. Kaplan-Meier statistics were used for analysis of clinical data. Both the MSBF and MBC were able to provide setup accuracy within 2 mm. With a median follow-up of 11 months, 35 patients (14 primary and 21 secondary malignancies) underwent treatment. The median dose previously received was 3000 cGy in 10 fractions. The median dose prescribed for these patients was 2000 cGy/5 fractions (2000-3000 cGy), which provided a median PTV V100 of 88%. In previously unirradiated patients, the median prescribed dose was 7000 cGy (5940-7000 cGy) with a median PTV V100 of 90%. The median Dmax to the cord was 34% and 68% for previously irradiated and never irradiated patients, respectively. More than 90% of patients experienced palliation from pain, weakness, or paresthesia; 75% and 81% of secondary and primary lesions, respectively, exhibited local control at the time of last follow-up. No cases of radiation-induced myelopathy or radiculopathy have thus far been encountered. Precision stereotactic and image-guided paraspinal IMRT allows the delivery of high doses of radiation in multiple fractions to tumors within close proximity to the spinal cord while respecting cord tolerance. Although preliminary, the clinical results are encouraging.

Resonance fluorescence revival in a voltage-controlled semiconductor quantum dot

NASA Astrophysics Data System (ADS)

Reigue, Antoine; Lemaître, Aristide; Gomez Carbonell, Carmen; Ulysse, Christian; Merghem, Kamel; Guilet, Stéphane; Hostein, Richard; Voliotis, Valia

2018-02-01

We demonstrate systematic resonance fluorescence recovery with near-unity emission efficiency in single quantum dots embedded in a charge-tunable device in a wave-guiding geometry. The quantum dot charge state is controlled by a gate voltage, through carrier tunneling from a close-lying Fermi sea, stabilizing the resonantly photocreated electron-hole pair. The electric field cancels out the charging/discharging mechanisms from nearby traps toward the quantum dots, responsible for the usually observed inhibition of the resonant fluorescence. Fourier transform spectroscopy as a function of the applied voltage shows a strong increase in the coherence time though not reaching the radiative limit. These charge controlled quantum dots can act as quasi-perfect deterministic single-photon emitters, with one laser pulse converted into one emitted single photon.

Time Projection Compton Spectrometer (TPCS). User`s guide

DOE Office of Scientific and Technical Information (OSTI.GOV)

Landron, C.O.; Baldwin, G.T.

1994-04-01

The Time Projection Compton Spectrometer (TPCS) is a radiation diagnostic designed to determine the time-integrated energy spectrum between 100 keV -- 2 MeV of flash x-ray sources. This guide is intended as a reference for the routine operator of the TPCS. Contents include a brief overview of the principle of operation, detailed component descriptions, detailed assembly and disassembly procedures, guide to routine operations, and troubleshooting flowcharts. Detailed principle of operation, signal analysis and spectrum unfold algorithms are beyond the scope of this guide; however, the guide makes reference to sources containing this information.

CLINICAL APPLICATION OF A DRILL GUIDE TEMPLATE FOR PEDICLE SCREW PLACEMENT IN SEVERE SCOLIOSIS.

PubMed

Li, Xin; Zhang, Yaoshen; Zhang, Qiang; Zhao, Changsong; Liu, Kun

2017-01-01

To evaluate the accuracy and the effect of drill guide template for pedicle screw placement in severe scoliosis. Eight patients with rigid scoliosis were enrolled, five males and three females, ranging from nine to 23 years old. A three-dimensional CT scan of the spine was performed and saved as a DICOM file type. The multi-level template was designed by Mimics software and manufactured according to the part of the most severe deformity. The drill template was placed on the corresponding vertebral surface. Pedicle screws were carefully inserted across the trajectory of the template. Postoperatively, the positions of the pedicle screws were evaluated by CT scan and graded for validation. No spinal cord injury or nerve damage occurred. All patients had satisfactory outcomes. The abnormalities and the measures observed during operation were the same as those found in the preoperative period. The position of the pedicle screws was accurate, according to the postoperative X-ray and CT scan. The rate of scoliosis correction was 60%. Compared with controls, surgery time, blood loss and radiation were significantly lower. With the application of multi-level template, the placement of pedicle screws shows high accuracy in scoliosis with shorter surgical time, less blood loss and less radiation exposure. Level of Evidence III, Retrospective Comparative Study.

Education and Training Needs in Radiation Oncology in India: Opportunities for Indo–US Collaborations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grover, Surbhi, E-mail: Surbhi.grover@uphs.upenn.edu; Chadha, Manjeet; Rengan, Ramesh

Purpose: To conduct a survey of radiation oncologists in India, to better understand specific educational needs of radiation oncology in India and define areas of collaboration with US institutions. Methods and Materials: A 20-question survey was distributed to members of the Association of Indian Radiation Oncologists and the Indian Brachytherapy Society between November 2013 and May 2014. Results: We received a total of 132 responses. Over 50% of the physicians treat more than 200 patients per day, use 2-dimensional or 3-dimensional treatment planning techniques, and approximately 50% use image guided techniques. For education needs, most respondents agreed that further education inmore » intensity modulated radiation therapy, image guided radiation therapy, stereotactic radiation therapy, biostatistics, and research methods for medical residents would be useful areas of collaboration with institutions in the United States. Other areas of collaboration include developing a structured training module for nursing, physics training, and developing a second-opinion clinic for difficult cases with faculty in the United States. Conclusion: Various areas of potential collaboration in radiation oncology education were identified through this survey. These include the following: establishing education programs focused on current technology, facilitating exchange programs for trainees in India to the United States, promoting training in research methods, establishing training modules for physicists and oncology nurses, and creating an Indo–US. Tumor Board. It would require collaboration between the Association of Indian Radiation Oncologists and the American Society for Radiation Oncology to develop these educational initiatives.« less

Education and Training Needs in Radiation Oncology in India: Opportunities for Indo-US Collaborations.

PubMed

Grover, Surbhi; Chadha, Manjeet; Rengan, Ramesh; Williams, Tim R; Morris, Zachary S; Morgan, David A L; Tripuraneni, Prabhakar; Hu, Kenneth; Viswanathan, Akila N

2015-12-01

To conduct a survey of radiation oncologists in India, to better understand specific educational needs of radiation oncology in India and define areas of collaboration with US institutions. A 20-question survey was distributed to members of the Association of Indian Radiation Oncologists and the Indian Brachytherapy Society between November 2013 and May 2014. We received a total of 132 responses. Over 50% of the physicians treat more than 200 patients per day, use 2-dimensional or 3-dimensional treatment planning techniques, and approximately 50% use image guided techniques. For education needs, most respondents agreed that further education in intensity modulated radiation therapy, image guided radiation therapy, stereotactic radiation therapy, biostatistics, and research methods for medical residents would be useful areas of collaboration with institutions in the United States. Other areas of collaboration include developing a structured training module for nursing, physics training, and developing a second-opinion clinic for difficult cases with faculty in the United States. Various areas of potential collaboration in radiation oncology education were identified through this survey. These include the following: establishing education programs focused on current technology, facilitating exchange programs for trainees in India to the United States, promoting training in research methods, establishing training modules for physicists and oncology nurses, and creating an Indo-US. Tumor Board. It would require collaboration between the Association of Indian Radiation Oncologists and the American Society for Radiation Oncology to develop these educational initiatives. Copyright © 2015 Elsevier Inc. All rights reserved.

Development of OSL system using two high-density blue LEDs equipped with liquid light guides

NASA Astrophysics Data System (ADS)

Choi, J. H.; Kim, M. J.; Cheong, C. S.; Hong, D. G.

2014-03-01

In recent years, considerable developments in optically stimulated luminescence (OSL) have been made in the fields of radiation dosimetry, age determination, and medical applications. A compact and economical OSL system comprising a precision x-y-z stage for loading 12 samples, a small X-ray generator for radiation dosing, and two powerful blue light emitting diodes (LEDs) for optical stimulation equipped with VIS liquid light guides (VIS-LLGs) has been developed. This paper describes the principal features of the system along with the examples of measurements performed by the system.

Current external beam radiation therapy quality assurance guidance: does it meet the challenges of emerging image-guided technologies?

PubMed

Palta, Jatinder R; Liu, Chihray; Li, Jonathan G

2008-01-01

The traditional prescriptive quality assurance (QA) programs that attempt to ensure the safety and reliability of traditional external beam radiation therapy are limited in their applicability to such advanced radiation therapy techniques as three-dimensional conformal radiation therapy, intensity-modulated radiation therapy, inverse treatment planning, stereotactic radiosurgery/radiotherapy, and image-guided radiation therapy. The conventional QA paradigm, illustrated by the American Association of Physicists in Medicine Radiation Therapy Committee Task Group 40 (TG-40) report, consists of developing a consensus menu of tests and device performance specifications from a generic process model that is assumed to apply to all clinical applications of the device. The complexity, variation in practice patterns, and level of automation of high-technology radiotherapy renders this "one-size-fits-all" prescriptive QA paradigm ineffective or cost prohibitive if the high-probability error pathways of all possible clinical applications of the device are to be covered. The current approaches to developing comprehensive prescriptive QA protocols can be prohibitively time consuming and cost ineffective and may sometimes fail to adequately safeguard patients. It therefore is important to evaluate more formal error mitigation and process analysis methods of industrial engineering to more optimally focus available QA resources on process components that have a significant likelihood of compromising patient safety or treatment outcomes.

Statistical Determination of the Gating Windows for Respiratory-Gated Radiotherapy Using a Visible Guiding System.

PubMed

Oh, Se An; Yea, Ji Woon; Kim, Sung Kyu

2016-01-01

Respiratory-gated radiation therapy (RGRT) is used to minimize the radiation dose to normal tissue in lung-cancer patients. Although determining the gating window in the respiratory phase of patients is important in RGRT, it is not easy. Our aim was to determine the optimal gating window when using a visible guiding system for RGRT. Between April and October 2014, the breathing signals of 23 lung-cancer patients were recorded with a real-time position management (RPM) respiratory gating system (Varian, USA). We performed statistical analysis with breathing signals to find the optimal gating window for guided breathing in RGRT. When we compared breathing signals before and after the breathing training, 19 of the 23 patients showed statistically significant differences (p < 0.05). The standard deviation of the respiration signals after breathing training was lowest for phases of 30%-70%. The results showed that the optimal gating window in RGRT is 40% (30%-70%) with respect to repeatability for breathing after respiration training with the visible guiding system. RGRT was performed with the RPM system to confirm the usefulness of the visible guiding system. The RPM system and our visible guiding system improve the respiratory regularity, which in turn should improve the accuracy and efficiency of RGRT.

Guide for preparing annual reports on radiation-safety testing of electronic products (general)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

For manufacturers of electronic products other than those for which a specific guide has been issued, the guide replaces the Guide for the Filing of Annual Reports (21 CFR Subchapter J, Section 1002.11), HHS Publication FDA 82-8127. The electronic product (general) annual reporting guide is applicable to the following products: products intended to produce x radiation (accelerators, analytical devices, therapy x-ray machines); microwave diathermy machines; cold-cathode discharge tubes; and vacuum switches and tubes operating at or above 15,000 volts. To carry out its responsibilities under Public Law 90-602, the Food and Drug Administration's Center for Devices and Radiological Health (CDRH)more » has issued a series of regulations contained in Title 21 of the Code of Federal Regulations (CFR). Part 1002 of 21 CFR deals with records and reports. Section 1002.61 categorizes electronic products into Groups A through C. Section 1002.30 requires manufacturers of products in Groups B and C to establish and maintain certain records, while Section 1002.11 requires such manufacturers to submit an Annual Report summarizing the contents of the required records. Section 1002.7 requires that reports conform to reporting guides issued by CDRH unless an acceptable justification for an alternate format is provided.« less

The role of external beam radiotherapy in the treatment of hepatocellular cancer.

PubMed

Chino, Fumiko; Stephens, Sarah Jo; Choi, Steve S; Marin, Daniele; Kim, Charles Y; Morse, Michael A; Godfrey, Devon J; Czito, Brian G; Willett, Christopher G; Palta, Manisha

2018-04-12

Hepatocellular carcinoma (HCC) is increasing in incidence and mortality. Although the prognosis remains poor, long-term survival has improved from 3% in 1970 to an 18% 5-year survival rate today. This is likely because of the introduction of well tolerated, oral antiviral therapies for hepatitis C. Curative options for patients with HCC are often limited by underlying liver dysfunction/cirrhosis and medical comorbidities. Less than one-third of patients are candidates for surgery, which is the current gold standard for cure. Nonsurgical treatments include embolotherapies, percutaneous ablation, and ablative radiation. Technological advances in radiation delivery in the past several decades now allow for safe and effective ablative doses to the liver. Conformal techniques allow for both dose escalation to target volumes and normal tissue sparing. Multiple retrospective and prospective studies have demonstrated that hypofractionated image-guided radiation therapy, used as monotherapy or in combination with other liver-directed therapies, can provide excellent local control that is cost effective. Therefore, as the HCC treatment paradigm continues to evolve, ablative radiation treatment has moved from a palliative treatment to both a "bridge to transplant" and a definitive treatment. Cancer 2018. © 2018 American Cancer Society. © 2018 American Cancer Society.

A Review of Shared Decision-Making and Patient Decision Aids in Radiation Oncology.

PubMed

Woodhouse, Kristina Demas; Tremont, Katie; Vachani, Anil; Schapira, Marilyn M; Vapiwala, Neha; Simone, Charles B; Berman, Abigail T

2017-06-01

Cancer treatment decisions are complex and may be challenging for patients, as multiple treatment options can often be reasonably considered. As a result, decisional support tools have been developed to assist patients in the decision-making process. A commonly used intervention to facilitate shared decision-making is a decision aid, which provides evidence-based outcomes information and guides patients towards choosing the treatment option that best aligns with their preferences and values. To ensure high quality, systematic frameworks and standards have been proposed for the development of an optimal aid for decision making. Studies have examined the impact of these tools on facilitating treatment decisions and improving decision-related outcomes. In radiation oncology, randomized controlled trials have demonstrated that decision aids have the potential to improve patient outcomes, including increased knowledge about treatment options and decreased decisional conflict with decision-making. This article provides an overview of the shared-decision making process and summarizes the development, validation, and implementation of decision aids as patient educational tools in radiation oncology. Finally, this article reviews the findings from decision aid studies in radiation oncology and offers various strategies to effectively implement shared decision-making into clinical practice.

Clarification of radiation-control regulations for diagnostic x-ray equipment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

The Office of Compliance and Surveillance of the Center for Devices and Radiological Health (CDRH) has received many requests for interpretation of the Federal regulations that relate to diagnostic x-ray equipment. Responses to these requests were originally issued as FDA Compliance Policy Guides, industry-wide letters, and letters to individuals. The document is a compilation of those responses that remain applicable. Guides or opinions that have been withdrawn or are now obsolete because they have been incorporated into the regulations are not included. The document consists of two sections: the General section, which contains information of a general nature; and themore » Specific section, which contains information specific to particular sections of the Federal Performance Standard for Diagnostic X-ray Equipment (21 CFR 1020.30-32). When the term 'Revised Language' appears in an item heading, it indicates English grammar correction; the term 'Revised' indicates an updated version of the original clarification.« less

Invasive Cardiologists Are Exposed to Greater Left Sided Cranial Radiation: The BRAIN Study (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures).

PubMed

Reeves, Ryan R; Ang, Lawrence; Bahadorani, John; Naghi, Jesse; Dominguez, Arturo; Palakodeti, Vachaspathi; Tsimikas, Sotirios; Patel, Mitul P; Mahmud, Ehtisham

2015-08-17

This study sought to determine radiation exposure across the cranium of cardiologists and the protective ability of a nonlead, XPF (barium sulfate/bismuth oxide) layered cap (BLOXR, Salt Lake City, Utah) during fluoroscopically guided, invasive cardiovascular (CV) procedures. Cranial radiation exposure and potential for protection during contemporary invasive CV procedures is unclear. Invasive cardiologists wore an XPF cap with radiation attenuation ability. Six dosimeters were fixed across the outside and inside of the cap (left, center, and right), and 3 dosimeters were placed outside the catheterization lab to measure ambient exposure. Seven cardiology fellows and 4 attending physicians (38.4 ± 7.2 years of age; all male) performed diagnostic and interventional CV procedures (n = 66.2 ± 27 cases/operator; fluoroscopy time: 14.9 ± 5.0 min). There was significantly greater total radiation exposure at the outside left and outside center (106.1 ± 33.6 mrad and 83.1 ± 18.9 mrad) versus outside right (50.2 ± 16.2 mrad; p < 0.001 for both) locations of the cranium. The XPF cap attenuated radiation exposure (42.3 ± 3.5 mrad, 42.0 ± 3.0 mrad, and 41.8 ± 2.9 mrad at the inside left, inside center, and inside right locations, respectively) to a level slightly higher than that of the ambient control (38.3 ± 1.2 mrad, p = 0.046). After subtracting ambient radiation, exposure at the outside left was 16 times higher than the inside left (p < 0.001) and 4.7 times higher than the outside right (p < 0.001). Exposure at the outside center location was 11 times higher than the inside center (p < 0.001), whereas no difference was observed on the right side. Radiation exposure to invasive cardiologists is significantly higher on the left and center compared with the right side of the cranium. Exposure may be reduced similar to an ambient control level by wearing a nonlead XPF cap. (Brain Radiation Exposure and Attenuation During Invasive Cardiology Procedures [BRAIN]; NCT01910272). Copyright © 2015 American College of Cardiology Foundation. Published by Elsevier Inc. All rights reserved.

Propagation of registration uncertainty during multi-fraction cervical cancer brachytherapy

NASA Astrophysics Data System (ADS)

Amir-Khalili, A.; Hamarneh, G.; Zakariaee, R.; Spadinger, I.; Abugharbieh, R.

2017-10-01

Multi-fraction cervical cancer brachytherapy is a form of image-guided radiotherapy that heavily relies on 3D imaging during treatment planning, delivery, and quality control. In this context, deformable image registration can increase the accuracy of dosimetric evaluations, provided that one can account for the uncertainties associated with the registration process. To enable such capability, we propose a mathematical framework that first estimates the registration uncertainty and subsequently propagates the effects of the computed uncertainties from the registration stage through to the visualizations, organ segmentations, and dosimetric evaluations. To ensure the practicality of our proposed framework in real world image-guided radiotherapy contexts, we implemented our technique via a computationally efficient and generalizable algorithm that is compatible with existing deformable image registration software. In our clinical context of fractionated cervical cancer brachytherapy, we perform a retrospective analysis on 37 patients and present evidence that our proposed methodology for computing and propagating registration uncertainties may be beneficial during therapy planning and quality control. Specifically, we quantify and visualize the influence of registration uncertainty on dosimetric analysis during the computation of the total accumulated radiation dose on the bladder wall. We further show how registration uncertainty may be leveraged into enhanced visualizations that depict the quality of the registration and highlight potential deviations from the treatment plan prior to the delivery of radiation treatment. Finally, we show that we can improve the transfer of delineated volumetric organ segmentation labels from one fraction to the next by encoding the computed registration uncertainties into the segmentation labels.

WE-DE-209-04: 3D Surface Image-Guided

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tang, X.

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

Radiation Exposure in Transjugular Intrahepatic Portosystemic Shunt Creation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miraglia, Roberto, E-mail: rmiraglia@ismett.edu; Maruzzelli, Luigi, E-mail: lmaruzzelli@ismett.edu; Cortis, Kelvin, E-mail: kelvincortis@ismett.edu

2016-02-15

PurposeTransjugular intrahepatic portosystemic shunt (TIPS) creation is considered as being one of the most complex procedures in abdominal interventional radiology. Our aim was twofold: quantification of TIPS-related patient radiation exposure in our center and identification of factors leading to reduced radiation exposure.Materials and methodsThree hundred and forty seven consecutive patients underwent TIPS in our center between 2007 and 2014. Three main procedure categories were identified: Group I (n = 88)—fluoroscopic-guided portal vein targeting, procedure done in an image intensifier-based angiographic system (IIDS); Group II (n = 48)—ultrasound-guided portal vein puncture, procedure done in an IIDS; and Group III (n = 211)—ultrasound-guided portal vein puncture, procedure donemore » in a flat panel detector-based system (FPDS). Radiation exposure (dose-area product [DAP], in Gy cm{sup 2} and fluoroscopy time [FT] in minutes) was retrospectively analyzed.ResultsDAP was significantly higher in Group I (mean ± SD 360 ± 298; median 287; 75th percentile 389 Gy cm{sup 2}) as compared to Group II (217 ± 130; 178; 276 Gy cm{sup 2}; p = 0.002) and Group III (129 ± 117; 70; 150 Gy cm{sup 2}p < 0.001). The difference in DAP between Groups II and III was also significant (p < 0.001). Group I had significantly longer FT (25.78 ± 13.52 min) as compared to Group II (20.45 ± 10.87 min; p = 0.02) and Group III (19.76 ± 13.34; p < 0.001). FT was not significantly different between Groups II and III (p = 0.73).ConclusionsReal-time ultrasound-guided targeting of the portal venous system during TIPS creation results in a significantly lower radiation exposure and reduced FT. Further reduction in radiation exposure can be achieved through the use of modern angiographic units with FPDS.« less

Superradiance for Atoms Trapped along a Photonic Crystal Waveguide

NASA Astrophysics Data System (ADS)

Goban, A.; Hung, C.-L.; Hood, J. D.; Yu, S.-P.; Muniz, J. A.; Painter, O.; Kimble, H. J.

2015-08-01

We report observations of superradiance for atoms trapped in the near field of a photonic crystal waveguide (PCW). By fabricating the PCW with a band edge near the D1 transition of atomic cesium, strong interaction is achieved between trapped atoms and guided-mode photons. Following short-pulse excitation, we record the decay of guided-mode emission and find a superradiant emission rate scaling as Γ¯SR∝N ¯Γ1 D for average atom number 0.19 ≲N ¯≲2.6 atoms, where Γ1 D/Γ'=1.0 ±0.1 is the peak single-atom radiative decay rate into the PCW guided mode, and Γ' is the radiative decay rate into all the other channels. These advances provide new tools for investigations of photon-mediated atom-atom interactions in the many-body regime.

A New Era of Image Guidance with Magnetic Resonance-guided Radiation Therapy for Abdominal and Thoracic Malignancies

PubMed Central

Paliwal, Bhudatt; Hill, Patrick; Bayouth, John E; Geurts, Mark W; Baschnagel, Andrew M; Bradley, Kristin A; Harari, Paul M; Rosenberg, Stephen; Brower, Jeffrey V; Wojcieszynski, Andrzej P; Hullett, Craig; Bayliss, R A; Labby, Zacariah E; Bassetti, Michael F

2018-01-01

Magnetic resonance-guided radiation therapy (MRgRT) offers advantages for image guidance for radiotherapy treatments as compared to conventional computed tomography (CT)-based modalities. The superior soft tissue contrast of magnetic resonance (MR) enables an improved visualization of the gross tumor and adjacent normal tissues in the treatment of abdominal and thoracic malignancies. Online adaptive capabilities, coupled with advanced motion management of real-time tracking of the tumor, directly allow for high-precision inter-/intrafraction localization. The primary aim of this case series is to describe MR-based interventions for localizing targets not well-visualized with conventional image-guided technologies. The abdominal and thoracic sites of the lung, kidney, liver, and gastric targets are described to illustrate the technological advancement of MR-guidance in radiotherapy. PMID:29872602

Modern Radiation Therapy for Nodal Non-Hodgkin Lymphoma—Target Definition and Dose Guidelines From the International Lymphoma Radiation Oncology Group

DOE Office of Scientific and Technical Information (OSTI.GOV)

Illidge, Tim, E-mail: Tim.Illidge@ics.manchester.ac.uk; Specht, Lena; Yahalom, Joachim

2014-05-01

Radiation therapy (RT) is the most effective single modality for local control of non-Hodgkin lymphoma (NHL) and is an important component of therapy for many patients. Many of the historic concepts of dose and volume have recently been challenged by the advent of modern imaging and RT planning tools. The International Lymphoma Radiation Oncology Group (ILROG) has developed these guidelines after multinational meetings and analysis of available evidence. The guidelines represent an agreed consensus view of the ILROG steering committee on the use of RT in NHL in the modern era. The roles of reduced volume and reduced doses aremore » addressed, integrating modern imaging with 3-dimensional planning and advanced techniques of RT delivery. In the modern era, in which combined-modality treatment with systemic therapy is appropriate, the previously applied extended-field and involved-field RT techniques that targeted nodal regions have now been replaced by limiting the RT to smaller volumes based solely on detectable nodal involvement at presentation. A new concept, involved-site RT, defines the clinical target volume. For indolent NHL, often treated with RT alone, larger fields should be considered. Newer treatment techniques, including intensity modulated RT, breath holding, image guided RT, and 4-dimensional imaging, should be implemented, and their use is expected to decrease significantly the risk for normal tissue damage while still achieving the primary goal of local tumor control.« less

Global Metabolomic Identification of Long-Term Dose-Dependent Urinary Biomarkers in Nonhuman Primates Exposed to Ionizing Radiation.

PubMed

Pannkuk, Evan L; Laiakis, Evagelia C; Authier, Simon; Wong, Karen; Fornace, Albert J

2015-08-01

Due to concerns surrounding potential large-scale radiological events, there is a need to determine robust radiation signatures for the rapid identification of exposed individuals, which can then be used to guide the development of compact field deployable instruments to assess individual dose. Metabolomics provides a technology to process easily accessible biofluids and determine rigorous quantitative radiation biomarkers with mass spectrometry (MS) platforms. While multiple studies have utilized murine models to determine radiation biomarkers, limited studies have profiled nonhuman primate (NHP) metabolic radiation signatures. In addition, these studies have concentrated on short-term biomarkers (i.e., <72 h). The current study addresses the need for biomarkers beyond 72 h using a NHP model. Urine samples were collected at 7 days postirradiation (2, 4, 6, 7 and 10 Gy) and processed with ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight (QTOF) MS, acquiring global metabolomic radiation signatures. Multivariate data analysis revealed clear separation between control and irradiated groups. Thirteen biomarkers exhibiting a dose response were validated with tandem MS. There was significantly higher excretion of l-carnitine, l-acetylcarnitine, xanthine and xanthosine in males versus females. Metabolites validated in this study suggest perturbation of several pathways including fatty acid β oxidation, tryptophan metabolism, purine catabolism, taurine metabolism and steroid hormone biosynthesis. In this novel study we detected long-term biomarkers in a NHP model after exposure to radiation and demonstrate differences between sexes using UPLC-QTOF-MS-based metabolomics technology.

TH-CD-202-09: Free-Breathing Proton MRI Functional Lung Avoidance Maps to Guide Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Capaldi, D; Sheikh, K; Parraga, G

Purpose: Pulmonary functional MRI using inhaled gas contrast agents was previously investigated as a way to identify well-functioning lung in patients with NSCLC who are clinical candidates for radiotherapy. Hyperpolarized noble-gas ({sup 3}He and {sup 129}Xe) MRI has also been optimized to measure functional lung information, but for a number of reasons, the clinical translation of this approach to guide radiotherapy planning has been limited. As an alternative, free-breathing pulmonary 1H MRI using clinically available MRI systems and pulse sequences provides a non-contrast-enhanced method to generate both ventilation and perfusion maps. Free-breathing {sup 1}H MRI exploits non-rigid registration and Fouriermore » decomposition of MRI signal intensity differences (Bauman et al., MRM, 2009) that may be generated during normal tidal breathing. Here, our objective was to generate free-breathing {sup 1}H MRI ventilation and lung function avoidance maps in patients with NSCLC as a way to guide radiation therapy planning. Methods: Stage IIIA/IIIB NSCLC patients (n=8, 68±9yr) provided written informed consent to a randomized controlled clinical trial ( https://clinicaltrials.gov/ct2/show/NCT02002052 ) that aimed to compare outcomes related to image-guided versus conventional radiation therapy planning. Hyperpolarized {sup 3}He/{sup 129}Xe and dynamic free tidal-breathing {sup 1}H MRI were acquired as previously described (Capaldi et al., Acad Radiol, 2015). Non-rigid registration was performed using the modality-independent-neighbourhood-descriptor (MIND) deformable approach (Heinrich et al., Med Image Anal, 2012). Ventilation-defect-percent ({sup 3}He:VDP{sub He}, {sup 129}Xe:VDP{sub Xe}, Free-breathing-{sup 1}H:VDP{sub FB}) and the corresponding ventilation maps were compared using Pearson correlation coefficients (r) and the Dice similarity coefficient (DSC). Results: VDP{sub FB} was significantly related to VDP{sub He} (r=.71; p=.04) and VDP{sub Xe} (r=.80; p=.01) and there were also strong spatial relationships (DSC{sub He}/DSC{sub Xe}=89±3%/77±11%). Conclusion: In this proof of concept study in NSCLC patients, free-breathing {sup 1}H MRI ventilation defects were quantitatively and spatially related to inhaled-noble-gas MRI ventilation defects. Free-breathing {sup 1}H MRI measures lung function/ventilation that can be used to optimize radiotherapy planning in NSCLC patients.« less

76 FR 25725 - Final Regulatory Guide: Issuance, Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-05

....18, Revision 2, ``Information Relevant to Ensuring that Occupational Radiation Exposures at Medical..., techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the..., ``Information Relevant to Ensuring that Occupational Radiation Exposures at Medical Institutions will be As Low...

A DICOM-RT based ePR radiation therapy information system for managing brain tumor patients

NASA Astrophysics Data System (ADS)

Liu, Brent J.; Law, Maria; Huang, H. K.; Zee, C. S.; Chan, Lawrence

2005-04-01

The need for comprehensive clinical image data and relevant information in image-guided Radiation Therapy (RT) is becoming steadily apparent. Multiple standalone systems utilizing the most technological advancements in imaging, therapeutic radiation, and computerized treatment planning systems acquire key data during the RT treatment course of a patient. One example are patients treated for brain tumors of greater sizes and irregular shapes that utilize state-of-the-art RT technology to deliver pinpoint accurate radiation doses. One such system, the Cyberknife, is a radiation treatment system that utilizes image-guided information to control a multi-jointed, six degrees of freedom, robotic arm to deliver precise and required radiation dose to the tumor site of a cancer patient. The image-guided system is capable of tracking the lesion orientations with respect to the patient"s position throughout the treatment process. This is done by correlating live radiographic images with pre-operative, CT and MR imaging information to determine relative patient and tumor position repeatedly over the course of the treatment. The disparate and complex data generated by the Cyberknife system along with related data is scattered throughout the RT department compromising an efficient clinical workflow since the data crucial for a clinical decision may be time-consuming to retrieve, temporarily missing, or even lost. To address these shortcomings, the ACR-NEMA Standards Committee extended its DICOM (Digital Imaging & Communications in Medicine) Standard from Radiology to RT by ratifying seven DICOM RT objects starting in 1997. However, they are rarely used by the RT community in daily clinical operations. In the past, the research focus of an RT department has primarily been developing new protocols and devices to improve treatment process and outcomes of cancer patients with minimal effort dedicated to integration of imaging and information systems. Our research, tightly-coupling radiology and RT information systems, represents a new frontier for medical informatics research that has never been previously considered. By combining our past experience in medical imaging informatics, DICOM-RT expertise, and system integration, we propose to test our hypothesis using a brain tumor case model that a DICOM-RT electronic patient record (ePR) system can improve clinical workflow efficiency for treatment and management of patients. This RT ePR system integrated with clinical images and RT data can impact the RT department in a similar fashion as PACS has already successfully done for Radiology. As a first step, the specific treatment case of patients with brain tumors specifically patients treated with the Cyberknife system will be the initial proof of concept for the research design, implementation, evaluation, and clinical relevance.

X-Ray Laser

DTIC Science & Technology

1991-01-31

Reflection in Relativistic Electron Beam Channel Radiation Systems, IEEE Trans. on Plasma Science 16(5), 548 (1988). 3. M. Strauss, P. Amendt, N...Reduced Radiation Losses in a Channeled-Beam X-Ray Laser by Bragg Reflection Coupling, Phys. Rev. A 39(11), 5791 (1989). 6. M. Strauss and N. Rostoker... Radiation Guiding in Channeling Beam X-Ray Laser by Bragg Reflection Coupling, Phys. Rev. A 40(12), 7097 (1989). 91-00870111 llllltl

Beam’s-eye-view dosimetrics (BEVD) guided rotational station parameter optimized radiation therapy (SPORT) planning based on reweighted total-variation minimization

NASA Astrophysics Data System (ADS)

Kim, Hojin; Li, Ruijiang; Lee, Rena; Xing, Lei

2015-03-01

Conventional VMAT optimizes aperture shapes and weights at uniformly sampled stations, which is a generalization of the concept of a control point. Recently, rotational station parameter optimized radiation therapy (SPORT) has been proposed to improve the plan quality by inserting beams to the regions that demand additional intensity modulations, thus formulating non-uniform beam sampling. This work presents a new rotational SPORT planning strategy based on reweighted total-variation (TV) minimization (min.), using beam’s-eye-view dosimetrics (BEVD) guided beam selection. The convex programming based reweighted TV min. assures the simplified fluence-map, which facilitates single-aperture selection at each station for single-arc delivery. For the rotational arc treatment planning and non-uniform beam angle setting, the mathematical model needs to be modified by additional penalty term describing the fluence-map similarity and by determination of appropriate angular weighting factors. The proposed algorithm with additional penalty term is capable of achieving more efficient and deliverable plans adaptive to the conventional VMAT and SPORT planning schemes by reducing the dose delivery time about 5 to 10 s in three clinical cases (one prostate and two head-and-neck (HN) cases with a single and multiple targets). The BEVD guided beam selection provides effective and yet easy calculating methodology to select angles for denser, non-uniform angular sampling in SPORT planning. Our BEVD guided SPORT treatment schemes improve the dose sparing to femoral heads in the prostate and brainstem, parotid glands and oral cavity in the two HN cases, where the mean dose reduction of those organs ranges from 0.5 to 2.5 Gy. Also, it increases the conformation number assessing the dose conformity to the target from 0.84, 0.75 and 0.74 to 0.86, 0.79 and 0.80 in the prostate and two HN cases, while preserving the delivery efficiency, relative to conventional single-arc VMAT plans.

Efficacy of a novel IGS system in atrial septal defect repair

NASA Astrophysics Data System (ADS)

Mefleh, Fuad N.; Baker, G. Hamilton; Kwartowitz, David M.

2013-03-01

Congenital heart disease occurs in 107.6 out of 10,000 live births, with Atrial Septal Defects (ASD) accounting for 10% of these conditions. Historically, ASDs were treated with open heart surgery using cardiopulmonary bypass, allowing a patch to be sewn over the defect. In 1976, King et al. demonstrated use of a transcatheter occlusion procedure, thus reducing the invasiveness of ASD repair. Localization during these catheter based procedures traditionally has relied on bi-plane fluoroscopy; more recently trans-esophageal echocardiography (TEE) and intra-cardiac echocardiography (ICE) have been used to navigate these procedures. Although there is a high success rate using the transcatheter occlusion procedure, fluoroscopy poses radiation dose risk to both patient and clinician. The impact of this dose to the patients is important as many of those undergoing this procedure are children, who have an increased risk associated with radiation exposure. Their longer life expectancy than adults provides a larger window of opportunity for expressing the damaging effects of ionizing radiation. In addition, epidemiologic studies of exposed populations have demonstrated that children are considerably more sensitive to the carcinogenic effects radiation. Image-guided surgery (IGS) uses pre-operative and intra-operative images to guide surgery or an interventional procedure. Central to every IGS system is a software application capable of processing and displaying patient images, registration between multiple coordinate systems, and interfacing with a tool tracking system. We have developed a novel image-guided surgery framework called Kit for Navigation by Image Focused Exploration (KNIFE). In this work we assess the efficacy of this image-guided navigation system for ASD repair using a series of mock clinical experiments designed to simulate ASD repair device deployment.

PROPOSAL FOR A SIMPLE AND EFFICIENT MONTHLY QUALITY MANAGEMENT PROGRAM ASSESSING THE CONSISTENCY OF ROBOTIC IMAGE-GUIDED SMALL ANIMAL RADIATION SYSTEMS

PubMed Central

Brodin, N. Patrik; Guha, Chandan; Tomé, Wolfgang A.

2015-01-01

Modern pre-clinical radiation therapy (RT) research requires high precision and accurate dosimetry to facilitate the translation of research findings into clinical practice. Several systems are available that provide precise delivery and on-board imaging capabilities, highlighting the need for a quality management program (QMP) to ensure consistent and accurate radiation dose delivery. An ongoing, simple, and efficient QMP for image-guided robotic small animal irradiators used in pre-clinical RT research is described. Protocols were developed and implemented to assess the dose output constancy (based on the AAPM TG-61 protocol), cone-beam computed tomography (CBCT) image quality and object representation accuracy (using a custom-designed imaging phantom), CBCT-guided target localization accuracy and consistency of the CBCT-based dose calculation. To facilitate an efficient read-out and limit the user dependence of the QMP data analysis, a semi-automatic image analysis and data representation program was developed using the technical computing software MATLAB. The results of the first six months experience using the suggested QMP for a Small Animal Radiation Research Platform (SARRP) are presented, with data collected on a bi-monthly basis. The dosimetric output constancy was established to be within ±1 %, the consistency of the image resolution was within ±0.2 mm, the accuracy of CBCT-guided target localization was within ±0.5 mm, and dose calculation consistency was within ±2 s (± 3 %) per treatment beam. Based on these results, this simple quality assurance program allows for the detection of inconsistencies in dosimetric or imaging parameters that are beyond the acceptable variability for a reliable and accurate pre-clinical RT system, on a monthly or bi-monthly basis. PMID:26425981

Proposal for a Simple and Efficient Monthly Quality Management Program Assessing the Consistency of Robotic Image-Guided Small Animal Radiation Systems.

PubMed

Brodin, N Patrik; Guha, Chandan; Tomé, Wolfgang A

2015-11-01

Modern pre-clinical radiation therapy (RT) research requires high precision and accurate dosimetry to facilitate the translation of research findings into clinical practice. Several systems are available that provide precise delivery and on-board imaging capabilities, highlighting the need for a quality management program (QMP) to ensure consistent and accurate radiation dose delivery. An ongoing, simple, and efficient QMP for image-guided robotic small animal irradiators used in pre-clinical RT research is described. Protocols were developed and implemented to assess the dose output constancy (based on the AAPM TG-61 protocol), cone-beam computed tomography (CBCT) image quality and object representation accuracy (using a custom-designed imaging phantom), CBCT-guided target localization accuracy and consistency of the CBCT-based dose calculation. To facilitate an efficient read-out and limit the user dependence of the QMP data analysis, a semi-automatic image analysis and data representation program was developed using the technical computing software MATLAB. The results of the first 6-mo experience using the suggested QMP for a Small Animal Radiation Research Platform (SARRP) are presented, with data collected on a bi-monthly basis. The dosimetric output constancy was established to be within ±1 %, the consistency of the image resolution was within ±0.2 mm, the accuracy of CBCT-guided target localization was within ±0.5 mm, and dose calculation consistency was within ±2 s (±3%) per treatment beam. Based on these results, this simple quality assurance program allows for the detection of inconsistencies in dosimetric or imaging parameters that are beyond the acceptable variability for a reliable and accurate pre-clinical RT system, on a monthly or bi-monthly basis.

R-IDEAL: A Framework for Systematic Clinical Evaluation of Technical Innovations in Radiation Oncology.

PubMed

Verkooijen, Helena M; Kerkmeijer, Linda G W; Fuller, Clifton D; Huddart, Robbert; Faivre-Finn, Corinne; Verheij, Marcel; Mook, Stella; Sahgal, Arjun; Hall, Emma; Schultz, Chris

2017-01-01

The pace of innovation in radiation oncology is high and the window of opportunity for evaluation narrow. Financial incentives, industry pressure, and patients' demand for high-tech treatments have led to widespread implementation of innovations before, or even without, robust evidence of improved outcomes has been generated. The standard phase I-IV framework for drug evaluation is not the most efficient and desirable framework for assessment of technological innovations. In order to provide a standard assessment methodology for clinical evaluation of innovations in radiotherapy, we adapted the surgical IDEAL framework to fit the radiation oncology setting. Like surgery, clinical evaluation of innovations in radiation oncology is complicated by continuous technical development, team and operator dependence, and differences in quality control. Contrary to surgery, radiotherapy innovations may be used in various ways, e.g., at different tumor sites and with different aims, such as radiation volume reduction and dose escalation. Also, the effect of radiation treatment can be modeled, allowing better prediction of potential benefits and improved patient selection. Key distinctive features of R-IDEAL include the important role of predicate and modeling studies (Stage 0), randomization at an early stage in the development of the technology, and long-term follow-up for late toxicity. We implemented R-IDEAL for clinical evaluation of a recent innovation in radiation oncology, the MRI-guided linear accelerator (MR-Linac). MR-Linac combines a radiotherapy linear accelerator with a 1.5-T MRI, aiming for improved targeting, dose escalation, and margin reduction, and is expected to increase the use of hypofractionation, improve tumor control, leading to higher cure rates and less toxicity. An international consortium, with participants from seven large cancer institutes from Europe and North America, has adopted the R-IDEAL framework to work toward coordinated, evidence-based introduction of the MR-Linac. R-IDEAL holds the promise for timely, evidence-based introduction of radiotherapy innovations with proven superior effectiveness, while preventing unnecessary exposure of patients to potentially harmful interventions.

Hypofractionated Radiation Therapy (66 Gy in 22 Fractions at 3 Gy per Fraction) for Favorable-Risk Prostate Cancer: Long-term Outcomes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patel, Nita; Faria, Sergio, E-mail: sergio.faria@muhc.mcgill.ca; Cury, Fabio

2013-07-01

Purpose: To report long-term outcomes of low- and intermediate-risk prostate cancer patients treated with high-dose hypofractionated radiation therapy (HypoRT). Methods and Materials: Patients with low- and intermediate-risk prostate cancer were treated using 3-dimensional conformal radiation therapy to a dose of 66 Gy in 22 daily fractions of 3 Gy without hormonal therapy. A uniform 7-mm margin was created around the prostate for the planning target volume, and treatment was prescribed to the isocenter. Treatment was delivered using daily ultrasound image-guided radiation therapy. Common Terminology Criteria for Adverse Events, version 3.0, was used to prospectively score toxicity. Biochemical failure was definedmore » as the nadir prostate-specific antigen level plus 2 ng/mL. Results: A total of 129 patients were treated between November 2002 and December 2005. With a median follow-up of 90 months, the 5- and 8-year actuarial biochemical control rates were 97% and 92%, respectively. The 5- and 8-year actuarial overall survival rates were 92% and 88%, respectively. Only 1 patient died from prostate cancer at 92 months after treatment, giving an 8-year actuarial cancer-specific survival of 98%. Radiation therapy was well tolerated, with 57% of patients not experiencing any acute gastrointestinal (GI) or genitourinary (GU) toxicity. For late toxicity, the worst grade ≥2 rate for GI and GU toxicity was 27% and 33%, respectively. There was no grade >3 toxicity. At last follow-up, the rate of grade ≥2 for both GI and GU toxicity was only 1.5%. Conclusions: Hypofractionation with 66 Gy in 22 fractions prescribed to the isocenter using 3-dimensional conformal radiation therapy produces excellent biochemical control rates, with moderate toxicity. However, this regimen cannot be extrapolated to the intensity modulated radiation therapy technique.« less

Postoperative Stereotactic Body Radiation Therapy (SBRT) for Spine Metastases: A Critical Review to Guide Practice

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redmond, Kristin J., E-mail: kjanson3@jhmi.edu; Lo, Simon S.; Fisher, Charles

Postoperative stereotactic body radiation therapy (SBRT) for metastatic spinal tumors is increasingly being performed in clinical practice. Whereas the fundamentals of SBRT practice for intact spinal metastases are established, there are as yet no comprehensive practice guidelines for the postoperative indications. In particular, there are unique considerations for patient selection and treatment planning specific to postoperative spine SBRT that are critical for safe and effective management. The purpose of this critical review is to discuss the rationale for treatment, describe those factors affecting surgical decision making, introduce modern surgical trends, and summarize treatment outcomes for both conventional postoperative external beammore » radiation therapy and postoperative spine SBRT. Lastly, an in-depth practical discussion with respect to treatment planning and delivery considerations is provided to help guide optimal practice.« less

Reporting on Radiation: A Content Analysis of Chernobyl Coverage.

ERIC Educational Resources Information Center

Friedman, Sharon M.; And Others

1987-01-01

Evaluates how well the media guided readers and viewers through the Chernobyl disaster. Concludes that the press and television did not provide enough radiation and risk information in their coverage of the Chernobyl accident, but what was provided was appropriate, even-handed, and conservative. (NKA)

An ultrasonically levitated noncontact stage using traveling vibrations on precision ceramic guide rails.

PubMed

Koyama, Daisuke; Ide, Takeshi; Friend, James R; Nakamura, Kentaro; Ueha, Sadayuki

2007-03-01

This paper presents a noncontact sliding table design and measurements of its performance via ultrasonic levitation. A slider placed atop two vibrating guide rails is levitated by an acoustic radiation force emitted from the rails. A flexural traveling wave propagating along the guide rails allows noncontact transportation of the slider. Permitting a transport mechanism that reduces abrasion and dust generation with an inexpensive and simple structure. The profile of the sliding table was designed using the finite-element analysis (FEA) for high levitation and transportation efficiency. The prototype sliding table was made of alumina ceramic (Al2O3) to increase machining accuracy and rigidity using a structure composed of a pair of guide rails with a triangular cross section and piezoelectric transducers. Two types of transducers were used: bolt-clamped Langevin transducers and bimorph transducers. A 40-mm long slider was designed to fit atop the two rail guides. Flexural standing waves and torsional standing waves were observed along the guide rails at resonance, and the levitation of the slider was obtained using the flexural mode even while the levitation distance was less than 10 microm. The levitation distance of the slider was measured while increasing the slider's weight. The levitation pressure, rigidity, and vertical displacement amplitude of the levitating slider thus were measured to be 6.7 kN/m2, 3.0 kN/microm/m2, and less than 1 microm, respectively. Noncontact transport of the slider was achieved using phased drive of the two transducers at either end of the vibrating guide rail. By controlling the phase difference, the slider transportation direction could be switched, and a maximum thrust of 13 mN was obtained.

Nimbus-7 Earth Radiation Budjet compact solar data set user's guide

NASA Technical Reports Server (NTRS)

Kyle, H. Lee; Penn, Lanning M.; Hoyt, Douglas; Love, Douglas; Vemury, Sastri; Vallette, Brenda J.

1994-01-01

Nimbus-7 Earth Radiation Budget (ERB) solar measurements extend from November 16, 1978, to December 13, 1993, but with data gaps in 1992 and 1993. The measurements include the total solar irradiance plus six broadband spectral components. The Channel 10c total irradiance data appears very stable, and the calibration, well done. A number of characterization problems remain in the spectral measurements. In the original program, the solar and Earth flux measurements were intermixed and spread over about 170 computer tapes. For easier access, the solar data have been collected into two compact data sets. All of the data are collected into 14 Summary Solar Tapes (SST's). In addition, two Channel 10c Solar Tapes (CST's) give a separate listing of the stable total solar irradiance measurements. Channel 10c calibration and orbital irradiance values are given on separate PC disks. This document gives data descriptions and formats, together with quality control and calibration procedures.

Interferometric Polarization Control

NASA Technical Reports Server (NTRS)

Wollack, Edward J. (Inventor); Moseley, Samuel H. (Inventor); Chuss, David T. (Inventor); Novak, Giles A. (Inventor)

2008-01-01

A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.

Interferometric polarization control

NASA Technical Reports Server (NTRS)

Wollack, Edward J. (Inventor); Novak, Giles A. (Inventor); Moseley, Samuel H. (Inventor); Chuss, David T. (Inventor)

2009-01-01

A signal conditioning module provides a polarimeter capability in a photometric system. The module may include multiple variable delay polarization modulators. Each modulator may include an input port, and a first arm formed to include a first reflector and first rooftop mirror arranged in opposed relationship. The first reflector may direct an input radiation signal to the first rooftop mirror. Each modulator also may include an output port and a second arm formed to include a second reflector and second rooftop mirror arranged in opposed relationship. The second reflector can guide a signal from the second rooftop mirror towards the output port to provide an output radiation signal. A beamsplitting grid may be placed between the first reflector and the first rooftop mirror, and also between the second reflector and the second rooftop mirror. A translation apparatus can provide adjustment relative to optical path length vis-a-vis the first arm, the second arm and the grid.

On the scattering directionality of a dielectric particle dimer of High Refractive Index.

PubMed

Barreda, Ángela I; Saleh, Hassan; Litman, Amélie; González, Francisco; Geffrin, Jean-Michel; Moreno, Fernando

2018-05-22

Low-losses and directionality effects exhibited by High Refractive Index Dielectric particles make them attractive for applications where radiation direction control is relevant. For instance, isolated metallo-dielectric core-shell particles or aggregates (dimers) of High Refractive Index Dielectric particles have been proposed for building operational switching devices. Also, the possibility of using isolated High Refractive Index Dielectric particles for optimizing solar cells performance has been explored. Here, we present experimental evidence in the microwave range, that a High Refractive Index Dielectric dimer of spherical particles is more efficient for redirecting the incident radiation in the forward direction than the isolated case. In fact, we report two spectral regions in the dipolar spectral range where the incident intensity is mostly scattered in the forward direction. They correspond to the Zero-Backward condition (also observed for isolated particles) and to a new condition, denoted as "near Zero-Backward" condition, which comes from the interaction effects between the particles. The proposed configuration has implications in solar energy harvesting devices and in radiation guiding.

Numerical study of electromagnetic waves generated by a prototype dielectric logging tool

USGS Publications Warehouse

Ellefsen, K.J.; Abraham, J.D.; Wright, D.L.; Mazzella, A.T.

2004-01-01

To understand the electromagnetic waves generated by a prototype dielectric logging tool, a numerical study was conducted using both the finite-difference, time-domain method and a frequency-wavenumber method. When the propagation velocity in the borehole was greater than that in the formation (e.g., an air-filled borehole in the unsaturated zone), only a guided wave propagated along the borehole. As the frequency decreased, both the phase and the group velocities of the guided wave asymptotically approached the phase velocity of a plane wave in the formation. The guided wave radiated electromagnetic energy into the formation, causing its amplitude to decrease. When the propagation velocity in the borehole was less than that in the formation (e.g., a water-filled borehole in the saturated zone), both a refracted wave and a guided wave propagated along the borehole. The velocity of the refracted wave equaled the phase velocity of a plane wave in the formation, and the refracted wave preceded the guided wave. As the frequency decreased, both the phase and the group velocities of the guided wave asymptotically approached the phase velocity of a plane wave in the formation. The guided wave did not radiate electromagnetic energy into the formation. To analyze traces recorded by the prototype tool during laboratory tests, they were compared to traces calculated with the finite-difference method. The first parts of both the recorded and the calculated traces were similar, indicating that guided and refracted waves indeed propagated along the prototype tool. ?? 2004 Society of Exploration Geophysicists. All rights reserved.

Quality assurance in nuclear medicine facilities; availability of final recommendations--FDA. Notice.

PubMed

1985-05-13

The Food and Drug Administration (FDA) is announcing the availability of final recommendations prepared by its Center for Devices and Radiological Health (CDRH) on quality assurance programs in nuclear medicine facilities. The final recommendations include the agency's rationale for the recommendations as well as references that can be used as well as references that can be used as guides in conducting quality control monitoring. These final recommendations are available as a technical report in CDRH's radiation recommendations series. They are intended to encourage and promote the development of voluntary quality assurance programs in nuclear medicine facilities.

Coherent Light induced in Optical Fiber by a Charged Particle

NASA Astrophysics Data System (ADS)

Artru, Xavier; Ray, Cédric

2016-07-01

Coherent light production in an optical fiber by a charged particle (named PIGL, for particle-induced guided, light) is reviewed. From the microscopic point of view, light is emitted by transient electric dipoles induced in the fiber medium by the Coulomb field of the particle. The phenomenon can also considered as the capture of virtual photons of the particle field by the fiber. Two types of captures are distinguished. Type-I takes place in a uniform part of the fiber; then the photon keeps its longitudinal momentum pz . Type-II takes place near an end or in a non-uniform part of the fiber; then pz is not conserved. Type-I PIGL is not affected by background lights external to the fiber. At grazing incidence it becomes nearly monochromatic. Its circular polarization depends on the angular momentum of the particle about the fiber and on the relative velocity between the particle and the guided wave. A general formula for the yield of Type-II radiation, based on the reciprocity theorem, is proposed. This radiation can be assisted by metallic objects stuck to the fiber, via plasmon excitation. A periodic structure leads to a guided Smith-Purcell radiation. Applications of PIGL in beam diagnostics are considered.

Five-Year Outcomes of High-Dose Single-Fraction Spinal Stereotactic Radiosurgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moussazadeh, Nelson; Department of Neurological Surgery, Weill Cornell Medical College, New York Presbyterian Hospital, New York, New York; Lis, Eric

Purpose: To characterize local tumor control and toxicity risk in very long-term survivors (>5 years) after high-dose spinal image guided, intensity modulated radiation therapy delivered as single-dose stereotactic radiosurgery (SRS). Previously published spinal SRS outcome analyses have included a heterogeneous population of cancer patients, mostly with short survival. This is the first study reporting the long-term tumor control and toxicity profiles after high-dose single-fraction spinal SRS. Methods and Materials: The study population included all patients treated from June 2004 to July 2009 with single-fraction spinal SRS (dose 24 Gy) who had survived at least 5 years after treatment. The endpoints examined included diseasemore » progression, surgical or radiation retreatment, in-field fracture development, and radiation-associated toxicity, scored using the Radiation Therapy Oncology Group radiation morbidity scoring criteria and the Common Terminology Criteria for Adverse Events, version 4.0. Local control and fracture development were assessed using Kaplan-Meier analysis. Results: Of 278 patients, 31 (11.1%), with 36 segments treated for spinal tumors, survived at least 5 years after treatment and were followed up radiographically and clinically for a median of 6.1 years (maximum 102 months). The histopathologic findings for the 5-year survivors included radiation-resistant metastases in 58%, radiation-sensitive metastases in 22%, and primary bone tumors in 19%. In this selected cohort, 3 treatment failures occurred at a median of 48.6 months, including 2 recurrences in the radiation field and 1 patient with demonstrated progression at the treatment margins. Ten lesions (27.8%) were associated with acute grade 1 cutaneous or gastrointestinal toxicity. Delayed toxicity ≥3 months after treatment included 8 cases (22.2%) of mild neuropathy, 2 (5.6%) of gastrointestinal discomfort, 8 (22.2%) of dermatitides, and 3 (8.3%) of myalgias/myositis. Thirteen treated levels (36.1%) in 12 patients demonstrated progressive vertebral body collapse or endplate fractures at a median of 25.7 months (range 11.6-76.0), of which 5 (14%) became symptomatic and subsequently required percutaneous cement augmentation or surgery. Conclusions: In the longest-term series to date, high-dose single-fraction spinal SRS retained an excellent safety profile among long-term survivors (>5 years)« less

75 FR 52999 - Notice of Issuance of Regulatory Guide

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-30

... or postulated accidents, and data that the staff needs in its review of applications for permits and... Regulations (10 CFR) Part 20, ``Standards for Protection Against Radiation,'' the associated specific... (i.e. radiation doses in addition to and accounted for separately from the doses received under the...

X-Rays: The Inside Story (Secondary). Teacher's Guide.

ERIC Educational Resources Information Center

Royal Australasian Coll. of Radiologists, Sydney (Australia).

The goals of this unit are to explore the magic, history, and development of imaging technology, clarify what X-rays and radiation are, examine the issues involved in imaging technology, understand basic anatomy, explore careers related to radiology, and promote future good health. Included in the unit are the teacher's guide, a collection of…

A novel radiation protection drape reduces radiation exposure during fluoroscopy guided electrophysiology procedures.

PubMed

Germano, Joseph J; Day, Gina; Gregorious, David; Natarajan, Venkataraman; Cohen, Todd

2005-09-01

The purpose of this study was to evaluate a novel disposable lead-free radiation protection drape for decreasing radiation scatter during electrophysiology procedures. In recent years, there has been an exponential increase in the number of electrophysiology (EP) procedures exposing patients, operators and laboratory staff to higher radiation doses. The RADPAD was positioned slightly lateral to the incision site for pectoral device implants and superior to the femoral vein during electrophysiology studies. Each patient served as their own control and dosimetric measurements were obtained at the examiner's elbow and hand. Radiation badge readings for the operator were obtained three months prior to RADPAD use and three months after introduction. Radiation dosimetry was obtained in twenty patients: 7 electrophysiology studies, 6 pacemakers, 5 catheter ablations, and 2 implantable cardioverter-defibrillators. Eleven women and nine men with a mean age of 63 +/- 4 years had an average fluoroscopy time of 2.5 +/- 0.42 minutes per case. Mean dosimetric measurements at the hand were reduced from 141.38 +/- 24.67 to 48.63 +/- 9.02 milliroentgen (mR) per hour using the protective drape (63% reduction; p < 0.0001). Measurements at the elbow were reduced from 78.78 +/- 7.95 mR per hour to 34.50 +/- 4.18 mR per hour using the drape (55% reduction; p < 0.0001). Badge readings for three months prior to drape introduction averaged 2.45 mR per procedure versus 1.54 mR per procedure for 3 months post-initiation (37% reduction). The use of a novel radiation protection surgical drape can significantly reduce scatter radiation exposure to staff and operators during a variety of EP procedures.

Real-time fluoroscopic needle guidance in the interventional radiology suite using navigational software for percutaneous bone biopsies in children.

PubMed

Shellikeri, Sphoorti; Setser, Randolph M; Hwang, Tiffany J; Srinivasan, Abhay; Krishnamurthy, Ganesh; Vatsky, Seth; Girard, Erin; Zhu, Xiaowei; Keller, Marc S; Cahill, Anne Marie

2017-07-01

Navigational software provides real-time fluoroscopic needle guidance for percutaneous procedures in the Interventional Radiology (IR) suite. We describe our experience with navigational software for pediatric percutaneous bone biopsies in the IR suite and compare technical success, diagnostic accuracy, radiation dose and procedure time with that of CT-guided biopsies. Pediatric bone biopsies performed using navigational software (Syngo iGuide, Siemens Healthcare) from 2011 to 2016 were prospectively included and anatomically matched CT-guided bone biopsies from 2008 to 2016 were retrospectively reviewed with institutional review board approval. C-arm CT protocols used for navigational software-assisted cases included institution-developed low-dose (0.1/0.17 μGy/projection), regular-dose (0.36 μGy/projection), or a combination of low-dose/regular-dose protocols. Estimated effective radiation dose and procedure times were compared between software-assisted and CT-guided biopsies. Twenty-six patients (15 male; mean age: 10 years) underwent software-assisted biopsies (15 pelvic, 7 lumbar and 4 lower extremity) and 33 patients (13 male; mean age: 9 years) underwent CT-guided biopsies (22 pelvic, 7 lumbar and 4 lower extremity). Both modality biopsies resulted in a 100% technical success rate. Twenty-five of 26 (96%) software-assisted and 29/33 (88%) CT-guided biopsies were diagnostic. Overall, the effective radiation dose was significantly lower in software-assisted than CT-guided cases (3.0±3.4 vs. 6.6±7.7 mSv, P=0.02). The effective dose difference was most dramatic in software-assisted cases using low-dose C-arm CT (1.2±1.8 vs. 6.6±7.7 mSv, P=0.001) or combined low-dose/regular-dose C-arm CT (1.9±2.4 vs. 6.6±7.7 mSv, P=0.04), whereas effective dose was comparable in software-assisted cases using regular-dose C-arm CT (6.0±3.5 vs. 6.6±7.7 mSv, P=0.7). Mean procedure time was significantly lower for software-assisted cases (91±54 vs. 141±68 min, P=0.005). In our experience, navigational software technology in the IR suite is a promising alternative to CT guidance for pediatric bone biopsies providing comparable technical success and diagnostic accuracy with lower radiation dose and procedure time, in addition to providing real-time fluoroscopic needle guidance.

Computed Tomography Number Changes Observed During Computed Tomography–Guided Radiation Therapy for Head and Neck Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Feng, Mei; Department of Radiation Oncology, Sichuan Cancer Hospital, Chengdu; Yang, Cungeng

2015-04-01

Purpose: To investigate CT number (CTN) changes in gross tumor volume (GTV) and organ at risk (OAR) according to daily diagnostic-quality CT acquired during CT-guided intensity modulated radiation therapy for head and neck cancer (HNC) patients. Methods and Materials: Computed tomography scans acquired using a CT-on-rails during daily CT-guided intensity modulated radiation therapy for 15 patients with stage II to IVa squamous cell carcinoma of the head and neck were analyzed. The GTV, parotid glands, spinal cord, and nonspecified tissue were generated on each selected daily CT. The changes in CTN distributions and the mean and mode values were collected.more » Pearson analysis was used to assess the correlation between the CTN change, organ volume reduction, and delivered radiation dose. Results: Volume and CTN changes for GTV and parotid glands can be observed during radiation therapy delivery for HNC. The mean (±SD) CTNs in GTV and ipsi- and contralateral parotid glands were reduced by 6 ± 10, 8 ± 7, and 11 ± 10 Hounsfield units, respectively, for all patients studied. The mean CTN changes in both spinal cord and nonspecified tissue were almost invisible (<2 Hounsfield units). For 2 patients studied, the absolute mean CTN changes in GTV and parotid glands were strongly correlated with the dose delivered (P<.001 and P<.05, respectively). For the correlation between CTN reductions and delivered isodose bins for parotid glands, the Pearson coefficient varied from −0.98 (P<.001) in regions with low-dose bins to 0.96 (P<.001) in high-dose bins and were patient specific. Conclusions: The CTN can be reduced in tumor and parotid glands during the course of radiation therapy for HNC. There was a fair correlation between CTN reduction and radiation doses for a subset of patients, whereas the correlation between CTN reductions and volume reductions in GTV and parotid glands were weak. More studies are needed to understand the mechanism for the radiation-induced CTN changes.« less

Hypofractionated Radiotherapy Is Superior to Conventional Fractionation in an Orthotopic Model of Anaplastic Thyroid Cancer.

PubMed

Oweida, Ayman; Phan, Andy; Vancourt, Benjamin; Robin, Tyler; Hararah, Mohammad K; Bhatia, Shilpa; Milner, Dallin; Lennon, Shelby; Pike, Laura; Raben, David; Haugen, Bryan; Pozdeyev, Nikita; Schweppe, Rebecca; Karam, Sana D

2018-06-01

Anaplastic thyroid cancer (ATC) is an aggressive and highly lethal disease with poor outcomes and resistance to therapy. Despite multimodality treatment, including radiation therapy and chemotherapy, response rates remain <15%, with a median time to progression of less than three months. Recent advances in radiotherapy (RT) delivery and gene-expression profiling may help guide patient selection for personalized therapy. The purpose of this study was to characterize the response to radiation in a panel of ATC cell lines and to test alternative RT fractionation schedules for overcoming radioresistance. The cellular response to radiation was characterized based on clonogenic assays. Radiation response was correlated with microarray gene-expression data. Hypofractionated and conventional RT was tested in an orthotopic ATC tumor model, and tumor growth was assayed locally and distantly with in vivo and ex vivo bioluminescence imaging. A spectrum of radiosensitivities was observed in ATC cell lines. Radioresistant cell lines had higher levels of CXCR4 compared to radiosensitive cell lines. Compared to conventionally fractionated RT, hypofractionated RT resulted in significantly improved tumor growth delay, decreased regional and distant metastases, and improved overall survival. The findings demonstrate the heterogeneity of response to radiation in ATC tumors and the superiority of hypofractionated RT in improving local control, metastatic spread, and survival in preclinical models. These data support the design of clinical trials targeting radioresistant pathways in combination with hypofractionated RT.

Rationale of technical requirements for NRG-BR001: The first NCI-sponsored trial of SBRT for the treatment of multiple metastases.

PubMed

Al-Hallaq, Hania A; Chmura, Steven; Salama, Joseph K; Winter, Kathryn A; Robinson, Clifford G; Pisansky, Thomas M; Borges, Virginia; Lowenstein, Jessica R; McNulty, Susan; Galvin, James M; Followill, David S; Timmerman, Robert D; White, Julia R; Xiao, Ying; Matuszak, Martha M

In 2014, the NRG Oncology Group initiated the first National Cancer Institute-sponsored, phase 1 clinical trial of stereotactic body radiation therapy (SBRT) for the treatment of multiple metastases in multiple organ sites (BR001; NCT02206334). The primary endpoint is to test the safety of SBRT for the treatment of 2 to 4 multiple lesions in several anatomic sites in a multi-institutional setting. Because of the technical challenges inherent to treating multiple lesions as their spatial separation decreases, we present the technical requirements for NRG-BR001 and the rationale for their selection. Patients with controlled primary tumors of breast, non-small cell lung, or prostate are eligible if they have 2 to 4 metastases distributed among 7 extracranial anatomic locations throughout the body. Prescription and organ-at-risk doses were determined by expert consensus. Credentialing requirements include (1) irradiation of the Imaging and Radiation Oncology Core phantom with SBRT, (2) submitting image guided radiation therapy case studies, and (3) planning the benchmark. Guidelines for navigating challenging planning cases including assessing composite dose are discussed. Dosimetric planning to multiple lesions receiving differing doses (45-50 Gy) and fractionation (3-5) while irradiating the same organs at risk is discussed, particularly for metastases in close proximity (≤5 cm). The benchmark case was selected to demonstrate the planning tradeoffs required to satisfy protocol requirements for 2 nearby lesions. Examples of passing benchmark plans exhibited a large variability in plan conformity. NRG-BR001 was developed using expert consensus on multiple issues from the dose fractionation regimen to the minimum image guided radiation therapy guidelines. Credentialing was tied to the task rather than the anatomic site to reduce its burden. Every effort was made to include a variety of delivery methods to reflect current SBRT technology. Although some simplifications were adopted, the successful completion of this trial will inform future designs of both national and institutional trials and would allow immediate clinical adoption of SBRT trials for oligometastases. Copyright © 2016 American Society for Radiation Oncology. Published by Elsevier Inc. All rights reserved.

Open-source, small-animal magnetic resonance-guided focused ultrasound system.

PubMed

Poorman, Megan E; Chaplin, Vandiver L; Wilkens, Ken; Dockery, Mary D; Giorgio, Todd D; Grissom, William A; Caskey, Charles F

2016-01-01

MR-guided focused ultrasound or high-intensity focused ultrasound (MRgFUS/MRgHIFU) is a non-invasive therapeutic modality with many potential applications in areas such as cancer therapy, drug delivery, and blood-brain barrier opening. However, the large financial costs involved in developing preclinical MRgFUS systems represent a barrier to research groups interested in developing new techniques and applications. We aim to mitigate these challenges by detailing a validated, open-source preclinical MRgFUS system capable of delivering thermal and mechanical FUS in a quantifiable and repeatable manner under real-time MRI guidance. A hardware and software package was developed that includes closed-loop feedback controlled thermometry code and CAD drawings for a therapy table designed for a preclinical MRI scanner. For thermal treatments, the modular software uses a proportional integral derivative controller to maintain a precise focal temperature rise in the target given input from MR phase images obtained concurrently. The software computes the required voltage output and transmits it to a FUS transducer that is embedded in the delivery table within the magnet bore. The delivery table holds the FUS transducer, a small animal and its monitoring equipment, and a transmit/receive RF coil. The transducer is coupled to the animal via a water bath and is translatable in two dimensions from outside the magnet. The transducer is driven by a waveform generator and amplifier controlled by real-time software in Matlab. MR acoustic radiation force imaging is also implemented to confirm the position of the focus for mechanical and thermal treatments. The system was validated in tissue-mimicking phantoms and in vivo during murine tumor hyperthermia treatments. Sonications were successfully controlled over a range of temperatures and thermal doses for up to 20 min with minimal temperature overshoot. MR thermometry was validated with an optical temperature probe, and focus visualization was achieved with acoustic radiation force imaging. We developed an MRgFUS platform for small-animal treatments that robustly delivers accurate, precise, and controllable sonications over extended time periods. This system is an open source and could increase the availability of low-cost small-animal systems to interdisciplinary researchers seeking to develop new MRgFUS applications and technology.

Radiation control in the intensive care unit for high intensity iridium-192 brain implants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sewchand, W.; Drzymala, R.E.; Amin, P.P.

A bedside lead cubicle was designed to minimize the radiation exposure of intensive care unit staff during routine interstitial brain irradiation by removable, high intensity iridium-192. The cubicle shields the patient without restricting intensive care routines. The design specifications were confirmed by exposure measurements around the shield with an implanted anthropomorphic phantom simulating the patient situation. The cubicle reduces the exposure rate around an implant patient by as much as 90%, with the exposure level not exceeding 0.1 mR/hour/mg of radium-equivalent /sup 192/Ir. Evaluation of data accumulated for the past 3 years has shown that the exposure levels of individualmore » attending nurses are 0.12 to 0.36 mR/mg of radium-equivalent /sup 192/Ir per 12-hour shift. The corresponding range for entire nursing teams varies between 0.18 and 0.26. A radiation control index (exposure per mg of radium-equivalent /sup 192/Ir per nurse-hour) is thus defined for individual nurses and nursing teams; this index is a significant guide to the planning of nurse rotations for brain implant patients with various /sup 192/Ir loads. The bedside shield reduces exposure from /sup 192/Ir implants by a factor of about 20, as expected, and the exposure from the lower energy radioisotope iodine-125 is barely detectable.« less

Applications of Machine Learning for Radiation Therapy.

PubMed

Arimura, Hidetaka; Nakamoto, Takahiro

2016-01-01

Radiation therapy has been highly advanced as image guided radiation therapy (IGRT) by making advantage of image engineering technologies. Recently, novel frameworks based on image engineering technologies as well as machine learning technologies have been studied for sophisticating the radiation therapy. In this review paper, the author introduces several researches of applications of machine learning for radiation therapy. For examples, a method to determine the threshold values for standardized uptake value (SUV) for estimation of gross tumor volume (GTV) in positron emission tomography (PET) images, an approach to estimate the multileaf collimator (MLC) position errors between treatment plans and radiation delivery time, and prediction frameworks for esophageal stenosis and radiation pneumonitis risk after radiation therapy are described. Finally, the author introduces seven issues that one should consider when applying machine learning models to radiation therapy.

In vivo reproducibility of robotic probe placement for a novel ultrasound-guided radiation therapy system

PubMed Central

Lediju Bell, Muyinatu A.; Sen, H. Tutkun; Iordachita, Iulian; Kazanzides, Peter; Wong, John

2014-01-01

Abstract. Ultrasound can provide real-time image guidance of radiation therapy, but the probe-induced tissue deformations cause local deviations from the treatment plan. If placed during treatment planning, the probe causes streak artifacts in required computed tomography (CT) images. To overcome these challenges, we propose robot-assisted placement of an ultrasound probe, followed by replacement with a geometrically identical, CT-compatible model probe. In vivo reproducibility was investigated by implanting a canine prostate, liver, and pancreas with three 2.38-mm spherical markers in each organ. The real probe was placed to visualize the markers and subsequently replaced with the model probe. Each probe was automatically removed and returned to the same position or force. Under position control, the median three-dimensional reproducibility of marker positions was 0.6 to 0.7 mm, 0.3 to 0.6 mm, and 1.1 to 1.6 mm in the prostate, liver, and pancreas, respectively. Reproducibility was worse under force control. Probe substitution errors were smallest for the prostate (0.2 to 0.6 mm) and larger for the liver and pancreas (4.1 to 6.3 mm), where force control generally produced larger errors than position control. Results indicate that position control is better than force control for this application, and the robotic approach has potential, particularly for relatively constrained organs and reproducibility errors that are smaller than established treatment margins. PMID:26158038

Semiconductor Based Transverse Bragg Resonance (TBR) Optical Amplifiers and Lasers

DTIC Science & Technology

2007-02-14

modes with small modal angles experience zero or very low radiation loss. We call these modes small modal angle (SMA) modes. SMA modes include both...lossless effective index-guided modes and low loss leaky modes. They are almost parallel to the graing and do not radiate significantly. As the modal...angle increases, all the modes experience higher radiation loss. However, around the transverse resonance angle of 13.80, low loss modes exist. These

Radiosensitizer-eluting nanocoatings on gold fiducials for biological in-situ image-guided radio therapy (BIS-IGRT)

NASA Astrophysics Data System (ADS)

Nagesha, D. K.; Tada, D. B.; Stambaugh, C. K. K.; Gultepe, E.; Jost, E.; Levy, C. O.; Cormack, R.; Makrigiorgos, G. M.; Sridhar, S.

2010-10-01

Image-guided radiation treatments (IGRT) routinely utilize radio-opaque implantable devices, such as fiducials or brachytherapy spacers, for improved spatial accuracy. The therapeutic efficiency of IGRT can be further enhanced by biological in situ dose painting (BIS-IGRT) of radiosensitizers through localized delivery within the tumor using gold fiducial markers that have been coated with nanoporous polymer matrices loaded with nanoparticles (NPs). In this work, two approaches were studied: (i) a free drug release system consisting of Doxorubicin (Dox), a hydrophilic drug, loaded into a non-degradable polymer poly(methyl methacrylate) (PMMA) coating and (ii) poly(d,l-lactic-co-glycolic acid) (PLGA) NPs loaded with fluorescent Coumarin-6, serving as a model for a hydrophobic drug, in a biodegradable chitosan matrix. Temporal release kinetics measurements in buffer were carried out using fluorescence spectroscopy. In the first case of free Dox release, an initial release within the first few hours was followed by a sustained release over the course of the next 3 months. In the second platform, release of NPs and the free drug was controlled by the degradation rate of the chitosan matrix and PLGA. The results show that dosage and rate of release of these radiosensitizers coated on gold fiducials for IGRT can be precisely tailored to achieve the desired release profile for radiation therapy of cancer.

MRI-guided Dose-escalated Salvage Radiotherapy for Bulky Bladder Neck Recurrence of Prostate Cancer

PubMed Central

Tyran, Marguerite; Steinberg, Michael L.; Holden, Stuart B; Cao, Minsong

2018-01-01

Nearly 30% of patients treated with radical prostatectomy for prostate cancer ultimately develop biochemical recurrences, and nearly a quarter of men with nonpalpable biochemical recurrences have gross local recurrences identified with magnetic resonance imaging (MRI). The only curative intervention for patients with recurrent disease after radical prostatectomy is salvage radiotherapy – this is particularly true for patients with gross local recurrences. Furthermore, even in patients with an incurable metastatic disease, a local recurrence can be the source of significant morbidity and should be addressed. Delivering a sufficient dose of radiation in the postoperative setting to control gross disease while minimizing toxicity poses a significant technical challenge. Because of the inherent uncertainty in the verification of gross disease positioning with standard onboard imaging technologies, large margins must be used. Larger margins, in turn, will lead to larger volumes of tissue receiving high doses of radiation, potentially increasing long-term toxicity. Herein, we present the case of a patient with a bulky gross recurrence (>40 cm3) at the bladder neck and synchronous metastatic disease who was referred for salvage radiotherapy after a multidisciplinary consensus recommendation to pursue local therapy for mitigating urinary morbidity from the bulky tumor. The case illustrates the utilization of MRI-guided radiotherapy to allow significant margin reduction, thereby facilitating the delivery of an escalated dose of radiotherapy to a bulky recurrence. PMID:29805929

Guiding tissue regeneration with ultrasound in vitro and in vivo

NASA Astrophysics Data System (ADS)

Dalecki, Diane; Comeau, Eric S.; Raeman, Carol H.; Child, Sally Z.; Hobbs, Laura; Hocking, Denise C.

2015-05-01

Developing new technologies that enable the repair or replacement of injured or diseased tissues is a major focus of regenerative medicine. This paper will discuss three ultrasound technologies under development in our laboratories to guide tissue regeneration both in vitro and in vivo. A critical obstacle in tissue engineering is the need for rapid and effective tissue vascularization strategies. To address this challenge, we are developing acoustic patterning techniques for microvascular tissue engineering. Acoustic radiation forces associated with ultrasound standing wave fields provide a rapid, non-invasive approach to spatially pattern cells in three dimensions without affecting cell viability. Acoustic patterning of endothelial cells leads to the rapid formation of microvascular networks throughout the volumes of three-dimensional hydrogels, and the morphology of the resultant microvessel networks can be controlled by design of the ultrasound field. A second technology under development uses ultrasound to noninvasively control the microstructure of collagen fibers within engineered tissues. The microstructure of extracellular matrix proteins provides signals that direct cell functions critical to tissue regeneration. Thus, controlling collagen microfiber structure with ultrasound provides a noninvasive approach to regulate the mechanical properties of biomaterials and control cellular responses. The third technology employs therapeutic ultrasound to enhance the healing of chronic wounds. Recent studies demonstrate increased granulation tissue thickness and collagen deposition in murine dermal wounds exposed to pulsed ultrasound. In summary, ultrasound technologies offer noninvasive approaches to control cell behaviors and extracellular matrix organization and thus hold great promise to advance tissue regeneration in vitro and in vivo.

Lean Six Sigma Applied to Ultrasound Guided Needle Biopsy in the Head and Neck.

PubMed

Matt, Bruce H; Woodward-Hagg, Heather K; Wade, Christopher L; Butler, Penny D; Kokoska, Mimi S

2014-07-01

(1) Confirm the positive value stream of office-based ultrasound using Lean Six Sigma; (2) demonstrate how ultrasound reduces time to diagnosis, costs, patient inconvenience and travel, exposure to ionizing radiation, intravenous contrast, and laboratory tests. Case series with historical controls using chart review. Tertiary Veterans Administration Hospital (university-affiliated). Patients with a consult request or decision for ultrasound guided fine needle aspiration (USFNA) from 2006 to 2012. Process evaluation using Lean Six Sigma methodologies; years study conducted: 2006-2012; outcome measurements: type of diagnostic tests and imaging studies including CT scans with associated radiation exposure, time to preliminary and final cytopathologic diagnosis, episodes of patient travel. Value stream mapping prior to and after implementing office-based ultrasound confirmed the time from consult request or decision for USFNA to completion of the USFNA was reduced from a range of 0 to 286 days requiring a maximum 17 steps to a range of 0 to 48 days, necessitating only a maximum of 9 steps. Office-based USFNA for evaluation of head and neck lesions reduced costs, time to diagnosis, risks and inconvenience to patients, radiation exposure, unnecessary laboratory, and patient complaints while increasing staff satisfaction. In addition, office-based ultrasound also changed the clinical management of specific patients. Lean Six Sigma reduces waste and optimizes quality and accuracy in manufacturing. This is the first known application of Lean Six Sigma to office-based USFNA in the evaluation of head and neck lesions. The literature supports the value of office-based ultrasound to patients and health care systems. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2014.

Robotically Driven CT-guided Needle Insertion: Preliminary Results in Phantom and Animal Experiments.

PubMed

Hiraki, Takao; Kamegawa, Tetsushi; Matsuno, Takayuki; Sakurai, Jun; Kirita, Yasuzo; Matsuura, Ryutaro; Yamaguchi, Takuya; Sasaki, Takanori; Mitsuhashi, Toshiharu; Komaki, Toshiyuki; Masaoka, Yoshihisa; Matsui, Yusuke; Fujiwara, Hiroyasu; Iguchi, Toshihiro; Gobara, Hideo; Kanazawa, Susumu

2017-11-01

Purpose To evaluate the accuracy of the remote-controlled robotic computed tomography (CT)-guided needle insertion in phantom and animal experiments. Materials and Methods In a phantom experiment, 18 robotic and manual insertions each were performed with 19-gauge needles by using CT fluoroscopic guidance for the evaluation of the equivalence of accuracy of insertion between the two groups with a 1.0-mm margin. Needle insertion time, CT fluoroscopy time, and radiation exposure were compared by using the Student t test. The animal experiments were approved by the institutional animal care and use committee. In the animal experiment, five robotic insertions each were attempted toward targets in the liver, kidneys, lungs, and hip muscle of three swine by using 19-gauge or 17-gauge needles and by using conventional CT guidance. The feasibility, safety, and accuracy of robotic insertion were evaluated. Results The mean accuracies of robotic and manual insertion in phantoms were 1.6 and 1.4 mm, respectively. The 95% confidence interval of the mean difference was -0.3 to 0.6 mm. There were no significant differences in needle insertion time, CT fluoroscopy time, or radiation exposure to the phantom between the two methods. Effective dose to the physician during robotic insertion was always 0 μSv, while that during manual insertion was 5.7 μSv on average (P < .001). Robotic insertion was feasible in the animals, with an overall mean accuracy of 3.2 mm and three minor procedure-related complications. Conclusion Robotic insertion exhibited equivalent accuracy as manual insertion in phantoms, without radiation exposure to the physician. It was also found to be accurate in an in vivo procedure in animals. © RSNA, 2017 Online supplemental material is available for this article.

WE-B-BRD-00: MRI for Radiation Oncology

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The use of MRI in radiation therapy is rapidly increasing. Applications vary from the MRI simulator, to the MRI fused with CT, and to the integrated MRI+RT system. Compared with the standard MRI QA, a broader scope of QA features has to be defined in order to maximize the benefits of using MRI in radiation therapy. These QA features include geometric fidelity, image registration, motion management, cross-system alignment, and hardware interference. Advanced MRI techniques require a specific type of QA, as they are being widely used in radiation therapy planning, dose calculations, post-implant dosimetry, and prognoses. A vigorous and adaptivemore » QA program is crucial to defining the responsibility of the entire radiation therapy group and detecting deviations from the performance of high-quality treatment. As a drastic departure from CT simulation, MRI simulation requires changes in the work flow of treatment planning and image guidance. MRI guided radiotherapy platforms are being developed and commercialized to take the advantage of the advance in knowledge, technology and clinical experience. This symposium will from an educational perspective discuss the scope and specific issues related to MRI guided radiotherapy. Learning Objectives: Understand the difference between a standard and a radiotherapy-specific MRI QA program. Understand the effects of MRI artifacts (geometric distortion and motion) on radiotherapy. Understand advanced MRI techniques (ultrashort echo, fast MRI including dynamic MRI and 4DMRI, diffusion, perfusion, and MRS) and related QA. Understand the methods to prepare MRI for treatment planning (electron density assignment, multimodality image registration, segmentation and motion management). Current status of MRI guided treatment platforms. Dr. Jihong Wang has a research grant with Elekta-MRL project. Dr. Ke Sheng receives research grants from Varian Medical systems.« less

Whole-brain spectroscopic MRI biomarkers identify infiltrating margins in glioblastoma patients

PubMed Central

Cordova, James S.; Shu, Hui-Kuo G.; Liang, Zhongxing; Gurbani, Saumya S.; Cooper, Lee A. D.; Holder, Chad A.; Olson, Jeffrey J.; Kairdolf, Brad; Schreibmann, Eduard; Neill, Stewart G.; Hadjipanayis, Constantinos G.; Shim, Hyunsuk

2016-01-01

Background The standard of care for glioblastoma (GBM) is maximal safe resection followed by radiation therapy with chemotherapy. Currently, contrast-enhanced MRI is used to define primary treatment volumes for surgery and radiation therapy. However, enhancement does not identify the tumor entirely, resulting in limited local control. Proton spectroscopic MRI (sMRI), a method reporting endogenous metabolism, may better define the tumor margin. Here, we develop a whole-brain sMRI pipeline and validate sMRI metrics with quantitative measures of tumor infiltration. Methods Whole-brain sMRI metabolite maps were coregistered with surgical planning MRI and imported into a neuronavigation system to guide tissue sampling in GBM patients receiving 5-aminolevulinic acid fluorescence-guided surgery. Samples were collected from regions with metabolic abnormalities in a biopsy-like fashion before bulk resection. Tissue fluorescence was measured ex vivo using a hand-held spectrometer. Tissue samples were immunostained for Sox2 and analyzed to quantify the density of staining cells using a novel digital pathology image analysis tool. Correlations among sMRI markers, Sox2 density, and ex vivo fluorescence were evaluated. Results Spectroscopic MRI biomarkers exhibit significant correlations with Sox2-positive cell density and ex vivo fluorescence. The choline to N-acetylaspartate ratio showed significant associations with each quantitative marker (Pearson's ρ = 0.82, P < .001 and ρ = 0.36, P < .0001, respectively). Clinically, sMRI metabolic abnormalities predated contrast enhancement at sites of tumor recurrence and exhibited an inverse relationship with progression-free survival. Conclusions As it identifies tumor infiltration and regions at high risk for recurrence, sMRI could complement conventional MRI to improve local control in GBM patients. PMID:26984746

A novel imaging approach for prostate cancer is tested in new clinical trial | Center for Cancer Research

Cancer.gov

Prostate cancer patients who have failed standard radiation therapy have the options of surgery, radioactive seed implantation or cryoablation. Deborah Citrin, M.D., of the Radiation Oncology Branch is leading a study of stereotactic body radiation therapy (SBRT) to treat prostate cancer that has recurred locally after standard radiation therapy. The goal of this study is to use a novel imaging approach to guide treatment and to define the best dose of SBRT for patients whose prostate cancer has recurred after standard radiotherapy. Read more...

Stereotactic Magnetic Resonance-guided Online Adaptive Radiotherapy for Oligometastatic Breast Cancer: A Case Report

PubMed Central

Cao, Minsong; Raldow, Ann C; Dang, Audrey; Lamb, James; Low, Daniel A; Steinberg, Michael L.; Lee, Percy

2018-01-01

We present a case of durable local control achieved in a patient treated with stereotactic magnetic resonance-guided adaptive radiation therapy (SMART) for an abdominal lymph node in the setting of oligometastatic breast cancer. A 50-year-old woman with a history of triple positive metastatic invasive ductal carcinoma of the left breast, stage IV (T3N2M1), underwent neoadjuvant chemotherapy, mastectomy, adjuvant radiotherapy and maintenance hormonal treatment with HER2 targeted therapies. At 20 months after definitive treatment of her primary, imaging showed an isolated progressive enlargement of lymph nodes between hepatic segment V/IVB and the neck of the pancreas. Radiofrequency ablation was considered, however, this approach was decided not to be optimal due to the proximity to stomach, and pancreatic duct. The patient was treated with SMART for 40 Gray in 5 fractions. Two and a half years later, the patient remains without evidence of disease progression. She experienced Grade 2 acute and late toxicity that was successfully managed with medications. This experience shows that SMART is a feasible and effective treatment to control the abdominal oligometastatic disease for breast cancer. PMID:29805937

Preliminary clinical outcomes of image-guided 3-dimensional conformal radiotherapy for limited brain metastases instead of stereotactic irradiation referral.

PubMed

Ohtakara, Kazuhiro; Hoshi, Hiroaki

2014-06-01

To determine the preliminary clinical outcomes of image-guided 3-dimensional conformal radiotherapy (IG-3DCRT) for limited but variably-sized brain metastases (BM). Sixty-two lesions in 24 patients were retrospectively evaluated; out of these patients 75% were ≥ 65 years of age, and 37.5% were categorized into recursive partitioning analysis (RPA) class 3. The median value for the maximum diameter of the lesions was 19 mm (range=4-72 mm). The median sole treatment dose was 36 Gy in 10 fractions. The median survival durations after IG-3DCRT were 12.0 months and 3.2 months for patients categorized into RPA classes ≤ 2 and 3, respectively. Local recurrences occurred in two lesions with a 6-month local control probability of 93.0%. Major toxicities included radiation necrosis in two patients. IG-3DCRT is feasible even for patients with limited BM who are categorized into RPA class 3, and confers clinical outcomes comparable to those of stereotactic radiosurgery, including excellent local control and minimal toxicity even for large tumors. Copyright© 2014 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Metal wires for terahertz wave guiding.

PubMed

Wang, Kanglin; Mittleman, Daniel M

2004-11-18

Sources and systems for far-infrared or terahertz (1 THz = 10(12) Hz) radiation have received extensive attention in recent years, with applications in sensing, imaging and spectroscopy. Terahertz radiation bridges the gap between the microwave and optical regimes, and offers significant scientific and technological potential in many fields. However, waveguiding in this intermediate spectral region still remains a challenge. Neither conventional metal waveguides for microwave radiation, nor dielectric fibres for visible and near-infrared radiation can be used to guide terahertz waves over a long distance, owing to the high loss from the finite conductivity of metals or the high absorption coefficient of dielectric materials in this spectral range. Furthermore, the extensive use of broadband pulses in the terahertz regime imposes an additional constraint of low dispersion, which is necessary for compatibility with spectroscopic applications. Here we show how a simple waveguide, namely a bare metal wire, can be used to transport terahertz pulses with virtually no dispersion, low attenuation, and with remarkable structural simplicity. As an example of this new waveguiding structure, we demonstrate an endoscope for terahertz pulses.

SU-E-J-47: Development of a High-Precision, Image-Guided Radiotherapy, Multi- Purpose Radiation Isocenter Quality-Assurance Calibration and Checking System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, C; Yan, G; Helmig, R

2014-06-01

Purpose: To develop a system that can define the radiation isocenter and correlate this information with couch coordinates, laser alignment, optical distance indicator (ODI) settings, optical tracking system (OTS) calibrations, and mechanical isocenter walkout. Methods: Our team developed a multi-adapter, multi-purpose quality assurance (QA) and calibration device that uses an electronic portal imaging device (EPID) and in-house image-processing software to define the radiation isocenter, thereby allowing linear accelerator (Linac) components to be verified and calibrated. Motivated by the concept that each Linac component related to patient setup for image-guided radiotherapy based on cone-beam CT should be calibrated with respect tomore » the radiation isocenter, we designed multiple concentric adapters of various materials and shapes to meet the needs of MV and KV radiation isocenter definition, laser alignment, and OTS calibration. The phantom's ability to accurately define the radiation isocenter was validated on 4 Elekta Linacs using a commercial ball bearing (BB) phantom as a reference. Radiation isocenter walkout and the accuracy of couch coordinates, ODI, and OTS were then quantified with the device. Results: The device was able to define the radiation isocenter within 0.3 mm. Radiation isocenter walkout was within ±1 mm at 4 cardinal angles. By switching adapters, we identified that the accuracy of the couch position digital readout, ODI, OTS, and mechanical isocenter walkout was within sub-mm. Conclusion: This multi-adapter, multi-purpose isocenter phantom can be used to accurately define the radiation isocenter and represents a potential paradigm shift in Linac QA. Moreover, multiple concentric adapters allowed for sub-mm accuracy for the other relevant components. This intuitive and user-friendly design is currently patent pending.« less

Image Guided Hypofractionated Postprostatectomy Intensity Modulated Radiation Therapy for Prostate Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, Stephen L.; Patel, Pretesh; Song, Haijun

2016-03-01

Purpose: Hypofractionated radiation therapy (RT) has promising long-term biochemical relapse-free survival (bRFS) with comparable toxicity for definitive treatment of prostate cancer. However, data reporting outcomes after adjuvant and salvage postprostatectomy hypofractionated RT are sparse. Therefore, we report the toxicity and clinical outcomes after postprostatectomy hypofractionated RT. Methods and Materials: From a prospectively maintained database, men receiving image guided hypofractionated intensity modulated RT (HIMRT) with 2.5-Gy fractions constituted our study population. Androgen deprivation therapy was used at the discretion of the radiation oncologist. Acute toxicities were graded according to the Common Terminology Criteria for Adverse Events version 4.0. Late toxicities weremore » scored using the Radiation Therapy Oncology Group/European Organization for Research and Treatment of Cancer scale. Biochemical recurrence was defined as an increase of 0.1 in prostate-specific antigen (PSA) from posttreatment nadir or an increase in PSA despite treatment. The Kaplan-Meier method was used for the time-to-event outcomes. Results: Between April 2008 and April 2012, 56 men received postoperative HIMRT. The median follow-up time was 48 months (range, 21-67 months). Thirty percent had pre-RT PSA <0.1; the median pre-RT detectable PSA was 0.32 ng/mL. The median RT dose was 65 Gy (range, 57.5-65 Gy). Ten patients received neoadjuvant and concurrent hormone therapy. Posttreatment acute urinary toxicity was limited. There was no acute grade 3 toxicity. Late genitourinary (GU) toxicity of any grade was noted in 52% of patients, 40% of whom had pre-RT urinary incontinence. The 4-year actuarial rate of late grade 3 GU toxicity (exclusively gross hematuria) was 28% (95% confidence interval [CI], 16%-41%). Most grade 3 GU toxicity resolved; only 7% had persistent grade ≥3 toxicity at the last follow-up visit. Fourteen patients experienced biochemical recurrence at a median of 20 months after radiation. The 4-year bPFS rate was 75% (95% CI, 63%-87%). Conclusions: The biochemical control in this series appears promising, although relatively short follow-up may lead to overestimation. Late grade 3 GU toxicity was higher than anticipated with hypofractionated radiation of 65 Gy to the prostate bed, although most resolved.« less

Patient and surgeon radiation exposure during spinal instrumentation using intraoperative computed tomography-based navigation.

PubMed

Mendelsohn, Daniel; Strelzow, Jason; Dea, Nicolas; Ford, Nancy L; Batke, Juliet; Pennington, Andrew; Yang, Kaiyun; Ailon, Tamir; Boyd, Michael; Dvorak, Marcel; Kwon, Brian; Paquette, Scott; Fisher, Charles; Street, John

2016-03-01

Imaging modalities used to visualize spinal anatomy intraoperatively include X-ray studies, fluoroscopy, and computed tomography (CT). All of these emit ionizing radiation. Radiation emitted to the patient and the surgical team when performing surgeries using intraoperative CT-based spine navigation was compared. This is a retrospective cohort case-control study. Seventy-three patients underwent CT-navigated spinal instrumentation and 73 matched controls underwent spinal instrumentation with conventional fluoroscopy. Effective doses of radiation to the patient when the surgical team was inside and outside of the room were analyzed. The number of postoperative imaging investigations between navigated and non-navigated cases was compared. Intraoperative X-ray imaging, fluoroscopy, and CT dosages were recorded and standardized to effective doses. The number of postoperative imaging investigations was compared with the matched cohort of surgical cases. A literature review identified historical radiation exposure values for fluoroscopic-guided spinal instrumentation. The 73 navigated operations involved an average of 5.44 levels of instrumentation. Thoracic and lumbar instrumentations had higher radiation emission from all modalities (CT, X-ray imaging, and fluoroscopy) compared with cervical cases (6.93 millisievert [mSv] vs. 2.34 mSv). Major deformity and degenerative cases involved more radiation emission than trauma or oncology cases (7.05 mSv vs. 4.20 mSv). On average, the total radiation dose to the patient was 8.7 times more than the radiation emitted when the surgical team was inside the operating room. Total radiation exposure to the patient was 2.77 times the values reported in the literature for thoracolumbar instrumentations performed without navigation. In comparison, the radiation emitted to the patient when the surgical team was inside the operating room was 2.50 lower than non-navigated thoracolumbar instrumentations. The average total radiation exposure to the patient was 5.69 mSv, a value less than a single routine lumbar CT scan (7.5 mSv). The average radiation exposure to the patient in the present study was approximately one quarter the recommended annual occupational radiation exposure. Navigation did not reduce the number of postoperative X-rays or CT scans obtained. Intraoperative CT navigation increases the radiation exposure to the patient and reduces the radiation exposure to the surgeon when compared with values reported in the literature. Intraoperative CT navigation improves the accuracy of spine instrumentation with acceptable patient radiation exposure and reduced surgical team exposure. Surgeons should be aware of the implications of radiation exposure to both the patient and the surgical team when using intraoperative CT navigation. Copyright © 2016 Elsevier Inc. All rights reserved.

Imaging Biomarker Dynamics in an Intracranial Murine Glioma Study of Radiation and Antiangiogenic Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chung, Caroline, E-mail: caroline.chung@rmp.uhn.on.ca; Jalali, Shahrzad; Foltz, Warren

2013-03-01

Purpose: There is a growing need for noninvasive biomarkers to guide individualized spatiotemporal delivery of radiation therapy (RT) and antiangiogenic (AA) therapy for brain tumors. This study explored early biomarkers of response to RT and the AA agent sunitinib (SU), in a murine intracranial glioma model, using serial magnetic resonance imaging (MRI). Methods and Materials: Mice with MRI-visible tumors were stratified by tumor size into 4 therapy arms: control, RT, SU, and SU plus RT (SURT). Single-fraction conformal RT was delivered using MRI and on-line cone beam computed tomography (CT) guidance. Serial MR images (T2-weighted, diffusion, dynamic contrast-enhanced and gadolinium-enhancedmore » T1-weighted scans) were acquired biweekly to evaluate tumor volume, apparent diffusion coefficient (ADC), and tumor perfusion and permeability responses (K{sub trans}, K{sub ep}). Results: Mice in all treatment arms survived longer than those in control, with a median survival of 35 days for SURT (P<.0001) and 30 days for RT (P=.009) and SU (P=.01) mice vs 26 days for control mice. At Day 3, ADC rise was greater with RT than without (P=.002). Sunitinib treatment reduced tumor perfusion/permeability values with mean K{sub trans} reduction of 27.6% for SU (P=.04) and 26.3% for SURT (P=.04) mice and mean K{sub ep} reduction of 38.1% for SU (P=.01) and 27.3% for SURT (P=.02) mice. The magnitude of individual mouse ADC responses at Days 3 and 7 correlated with subsequent tumor growth rate R values of −0.878 (P=.002) and −0.80 (P=.01), respectively. Conclusions: Early quantitative changes in diffusion and perfusion MRI measures reflect treatment responses soon after starting therapy and thereby raise the potential for these imaging biomarkers to guide adaptive and potentially individualized therapy approaches in the future.« less

Implementation of Remote 3-Dimensional Image Guided Radiation Therapy Quality Assurance for Radiation Therapy Oncology Group Clinical Trials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cui Yunfeng; Galvin, James M.; Radiation Therapy Oncology Group, American College of Radiology, Philadelphia, Pennsylvania

2013-01-01

Purpose: To report the process and initial experience of remote credentialing of three-dimensional (3D) image guided radiation therapy (IGRT) as part of the quality assurance (QA) of submitted data for Radiation Therapy Oncology Group (RTOG) clinical trials; and to identify major issues resulting from this process and analyze the review results on patient positioning shifts. Methods and Materials: Image guided radiation therapy datasets including in-room positioning CT scans and daily shifts applied were submitted through the Image Guided Therapy QA Center from institutions for the IGRT credentialing process, as required by various RTOG trials. A centralized virtual environment is establishedmore » at the RTOG Core Laboratory, containing analysis tools and database infrastructure for remote review by the Physics Principal Investigators of each protocol. The appropriateness of IGRT technique and volumetric image registration accuracy were evaluated. Registration accuracy was verified by repeat registration with a third-party registration software system. With the accumulated review results, registration differences between those obtained by the Physics Principal Investigators and from the institutions were analyzed for different imaging sites, shift directions, and imaging modalities. Results: The remote review process was successfully carried out for 87 3D cases (out of 137 total cases, including 2-dimensional and 3D) during 2010. Frequent errors in submitted IGRT data and challenges in the review of image registration for some special cases were identified. Workarounds for these issues were developed. The average differences of registration results between reviewers and institutions ranged between 2 mm and 3 mm. Large discrepancies in the superior-inferior direction were found for megavoltage CT cases, owing to low spatial resolution in this direction for most megavoltage CT cases. Conclusion: This first experience indicated that remote review for 3D IGRT as part of QA for RTOG clinical trials is feasible and effective. The magnitude of registration discrepancy between institution and reviewer was presented, and the major issues were investigated to further improve this remote evaluation process.« less

Scalable pumping approach for extracting the maximum TEM(00) solar laser power.

PubMed

Liang, Dawei; Almeida, Joana; Vistas, Cláudia R

2014-10-20

A scalable TEM(00) solar laser pumping approach is composed of four pairs of first-stage Fresnel lens-folding mirror collectors, four fused-silica secondary concentrators with light guides of rectangular cross-section for radiation homogenization, four hollow two-dimensional compound parabolic concentrators for further concentration of uniform radiations from the light guides to a 3 mm diameter, 76 mm length Nd:YAG rod within four V-shaped pumping cavities. An asymmetric resonator ensures an efficient large-mode matching between pump light and oscillating laser light. Laser power of 59.1 W TEM(00) is calculated by ZEMAX and LASCAD numerical analysis, revealing 20 times improvement in brightness figure of merit.

The Austrian radiation monitoring network ARAD - best practice and added value

NASA Astrophysics Data System (ADS)

Olefs, Marc; Baumgartner, Dietmar J.; Obleitner, Friedrich; Bichler, Christoph; Foelsche, Ulrich; Pietsch, Helga; Rieder, Harald E.; Weihs, Philipp; Geyer, Florian; Haiden, Thomas; Schöner, Wolfgang

2016-04-01

The Austrian RADiation monitoring network (ARAD) has been established to advance the national climate monitoring and to support satellite retrieval, atmospheric modeling and the development of solar energy techniques. Measurements cover the downward solar and thermal infrared radiation using instruments according to Baseline Surface Radiation Network (BSRN) standards. A unique feature of ARAD is its vertical dimension of five stations, covering an altitude range between about 200 m a.s.l (Vienna) and 3100 m a.s.l. (BSRN site Sonnblick). The paper outlines the aims and scopes of ARAD, its measurement and calibration standards, methods, strategies and station locations. ARAD network operation uses innovative data processing for quality assurance and quality control, utilizing manual and automated control algorithms. A combined uncertainty estimate for the broadband shortwave radiation fluxes at all five ARAD stations, using the methodology specified by the Guide to the Expression of Uncertainty in Measurement indicates that relative accuracies range from 1.5 to 2.9 % for large signals (global, direct: 1000 W m-2, diffuse: 500 W m-2) and from 1.7 to 23 % (or 0.9 to 11.5 W m-2) for small signals (50 W m-2) (expanded uncertainties corresponding to the 95 % confidence level). If the directional response error of the pyranometers and the temperature response of the instruments and the data acquisition system (DAQ) are corrected, this expanded uncertainty reduces to 1.4 to 2.8 % for large signals and to 1.7 to 5.2 % (or 0.9-2.6 W m-2) for small signals. Thus, for large signals of global and diffuse radiation, BSRN target accuracies are met or nearly met (missed by less than 0.2 percentage points, pps) for 70 % of the ARAD measurements after this correction. For small signals of direct radiation, BSRN targets are achieved at two sites and nearly met (also missed by less than 0.2 pps) at the other sites. For small signals of global and diffuse radiation, targets are achieved at all stations. Additional accuracy gains can be achieved in the future through additional measurements, corrections and a further upgrade of the DAQ. However, to improve the accuracy of measurements of direct solar radiation, improved instrument accuracy is needed. ARAD could serve as a useful example for establishing state-of-the-art radiation monitoring at the national level with a multiple-purpose approach. Instrumentation, guidelines and tools (such as the data quality control) developed within ARAD are intended to increase monitoring capabilities of global radiation and thus designed to allow straightforward adoption in other regions, without high development costs.

Radiation changes in vaginal and cervical cytology in carcinoma of the cervix uteri

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gupta, S.; Gupta, Y.N.; Sanyal, B.

1982-02-01

Radiation changes are observed in all postirradiated smears of squamous cell carcinoma of the cervix from 56 females, although to a variable degree. After 1 year the changes subside gradually. A high cornification index is a good guide for recurrence. The significance of dysplastic cells as premonition for recurrence is debatable. The presence of malignant cells at any stage was considered of grave significance, and indicates poor radiation response or recurrence.

On the Retirement of E.P. Goldfinch, Founder of Radiation Protection Dosimetry

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, Joseph C.; Horowitz, Yigal S.

This special issue of Radiation Protection Dosimetry commemorates the many years of service Eddie has dedicated to the international radiation protection community. Beginning with its first issue in 1981, Eddie led RPD to its current prominence with a guiding hand and Solomon-like wisdom, coupled with keen common sense which will be sorely missed. But, there is no doubt that the journal he created will continue to flourish in the foreseeable future.

Development of a novel gamma probe for detecting radiation direction

NASA Astrophysics Data System (ADS)

Pani, R.; Pellegrini, R.; Cinti, M. N.; Longo, M.; Donnarumma, R.; D'Alessio, A.; Borrazzo, C.; Pergola, A.; Ridolfi, S.; De Vincentis, G.

2016-01-01

Spatial localization of radioactive sources is currently a main issue interesting different fields, including nuclear industry, homeland security as well as medical imaging. It is currently achieved using different systems, but the development of technologies for detecting and characterizing radiation is becoming important especially in medical imaging. In this latter field, radiation detection probes have long been used to guide surgery, thanks to their ability to localize and quantify radiopharmaceutical uptake even deep in tissue. Radiolabelled colloid is injected into, or near to, the tumor and the surgeon uses a hand-held radiation detector, the gamma probe, to identify lymph nodes with radiopharmaceutical uptkake. The present work refers to a novel scintigraphic goniometric probe to identify gamma radiation and its direction. The probe incorporates several scintillation crystals joined together in a particular configuration to provide data related to the position of a gamma source. The main technical characteristics of the gamma locator prototype, i.e. sensitivity, spatial resolution and detection efficiency, are investigated. Moreover, the development of a specific procedure applied to the images permits to retrieve the source position with high precision with respect to the currently used gamma probes. The presented device shows a high sensitivity and efficiency to identify gamma radiation taking a short time (from 30 to 60 s). Even though it was designed for applications in radio-guided surgery, it could be used for other purposes, as for example homeland security.

Analysis of astigmatism of gain guided laser with a tapered-stripe geometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mamine, T.; Oda, T.; Yoneyama, O.

1984-12-01

The astigmatism of the tapered-stripe (TAPS) laser has been analyzed. Calculating the near-field spot size and the radius of curvature in the tapered-stripe region, the astigmatism is determined by using the expression of D = R/sub e/ (1+(lambdaR/sub e// ..pi..w/sup 2//sub e/)/sup 2/)/sup -1/. In our formalism we assume that the gain profile is parabola and the near-field spot size at the facet is determined by the diffusion length of injected carriers. So far as these assumptions are valid, it is concluded that the amount of astigmatism is reduced with the length of tapered stripe, using the refractive index changemore » due to the band-edge absorption of -10/sup -2/. The fundamental characteristics of the gain guided laser with TAPS structure such as the astigmatism, far-field radiation pattern, and the spontaneous emission factor are shown to be controlled by properly designing the stripe geometry and the thickness of the active layer.« less

MRI-Guided Focused Ultrasound Surgery

PubMed Central

Jolesz, Ferenc A.

2014-01-01

MRI-guided focused ultrasound (MRgFUS) surgery is a noninvasive thermal ablation method that uses magnetic resonance imaging (MRI) for target definition, treatment planning, and closed-loop control of energy deposition. Integrating FUS and MRI as a therapy delivery system allows us to localize, target, and monitor in real time, and thus to ablate targeted tissue without damaging normal structures. This precision makes MRgFUS an attractive alternative to surgical resection or radiation therapy of benign and malignant tumors. Already approved for the treatment of uterine fibroids, MRgFUS is in ongoing clinical trials for the treatment of breast, liver, prostate, and brain cancer and for the palliation of pain in bone metastasis. In addition to thermal ablation, FUS, with or without the use of microbubbles, can temporarily change vascular or cell membrane permeability and release or activate various compounds for targeted drug delivery or gene therapy. A disruptive technology, MRgFUS provides new therapeutic approaches and may cause major changes in patient management and several medical disciplines. PMID:19630579

Dosimetric verification for primary focal hypermetabolism of nasopharyngeal carcinoma patients treated with dynamic intensity-modulated radiation therapy.

PubMed

Xin, Yong; Wang, Jia-Yang; Li, Liang; Tang, Tian-You; Liu, Gui-Hong; Wang, Jian-She; Xu, Yu-Mei; Chen, Yong; Zhang, Long-Zhen

2012-01-01

To make sure the feasibility with (18F)FDG PET/CT to guided dynamic intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma patients, by dosimetric verification before treatment. Chose 11 patients in III~IVA nasopharyngeal carcinoma treated with functional image-guided IMRT and absolute and relative dosimetric verification by Varian 23EX LA, ionization chamber, 2DICA of I'mRT Matrixx and IBA detachable phantom. Drawing outline and making treatment plan were by different imaging techniques (CT and (18F)FDG PET/CT). The dose distributions of the various regional were realized by SMART. The absolute mean errors of interest area were 2.39%±0.66 using 0.6 cc ice chamber. Results using DTA method, the average relative dose measurements within our protocol (3%, 3 mm) were 87.64% at 300 MU/min in all filed. Dosimetric verification before IMRT is obligatory and necessary. Ionization chamber and 2DICA of I'mRT Matrixx was the effective dosimetric verification tool for primary focal hyper metabolism in functional image-guided dynamic IMRT for nasopharyngeal carcinoma. Our preliminary evidence indicates that functional image-guided dynamic IMRT is feasible.

Guide for SUNSafe Schools.

ERIC Educational Resources Information Center

Heidorn, Keith C.; Torrie, Bruce

As a result of the decline in the thickness of the atmospheric ozone layer, the surface of the Earth will be exposed to increased levels of solar ultraviolet B radiation. This radiation has been shown to have harmful effects for life on Earth. These include damage to plants, animals, and materials. It has also been linked to many human health…

The SunWise School Program Guide: A School Program that Radiates Good Ideas

ERIC Educational Resources Information Center

US Environmental Protection Agency, 2003

2003-01-01

To help educators raise sun safety awareness, the U.S. Environmental Protection Agency (EPA) has developed the SunWise School Program, a national education program for children in grades K through 8. SunWise Partner Schools sponsor classroom and schoolwide activities that raise children's awareness of stratospheric ozone depletion, UV radiation,…

[Interventional radiology and radiation therapy].

PubMed

Hadjiev, Janaki

2015-04-26

The revolutionary role of modern cross-sectional imaging, the improved target definition in CT/MRI image guided brachytherapy, the precise topography for applicator and anatomy contribute to a better knowledge and management of tumors and critical organs. Further developments and functional imaging is expected to lead to a broad use of patient tailored therapy in the field of interventional radiation oncology.

Design Principles and Practices for Controlling Hazards of Electromagnetic Radiation to Ordnance (HERO Design Guide). Revision 1

DTIC Science & Technology

1974-09-15

wvironmental, levels of Table, 2o.A.. C- antenn pi tn dD. Most radz. systems use. pulse modulation as opposed to the continuous carrier, or doppler...d:io- 11 m:,.ncLlc fleld (ai’pere tu-,na/zcter), a;:,i c -t wLn -, -i n , 2 func- tion i . i’.*:av antcrian, currci.L loop ’,, or cavity PA - power...8217.,, , -... :. ; Best at a leL,_ t )4AVSEA OD 30303 FIR$T TUwV5o.4 Disivibuied BildewireCylindrical Cavity (a) Vertical or Loop Antenrn Unsah’~ Med rnb

A Review of Hypersonics Aerodynamics, Aerothermodynamics and Plasmadynamics Activities within NASA's Fundamental Aeronautics Program

NASA Technical Reports Server (NTRS)

Salas, Manuel D.

2007-01-01

The research program of the aerodynamics, aerothermodynamics and plasmadynamics discipline of NASA's Hypersonic Project is reviewed. Details are provided for each of its three components: 1) development of physics-based models of non-equilibrium chemistry, surface catalytic effects, turbulence, transition and radiation; 2) development of advanced simulation tools to enable increased spatial and time accuracy, increased geometrical complexity, grid adaptation, increased physical-processes complexity, uncertainty quantification and error control; and 3) establishment of experimental databases from ground and flight experiments to develop better understanding of high-speed flows and to provide data to validate and guide the development of simulation tools.

A novel coaxial Ku-band transit radiation oscillator without external guiding magnetic field

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ling, Junpu, E-mail: lingjunpu@163.com; Zhang, Jiande; He, Juntao

2014-02-15

A novel coaxial transit radiation oscillator without external guiding magnetic field is designed to generate high power microwave at Ku-band. By using a coaxial structure, the space-charge potential energy is suppressed significantly, that is good for enhancing efficient beam-wave interaction. In order to improve the transmission stability of the unmagnetized intense relativistic electron beam, a Pierce-like cathode is employed in the novel device. By contrast with conventional relativistic microwave generators, this kind of device has the advantages of high stability, non-guiding magnetic field, and high efficiency. Moreover, with the coaxial design, it is possible to improve the power-handing capacity bymore » increasing the radial dimension of the Ku-band device. With a 550 keV and 7.5 kA electron beam, a 1.25 GW microwave pulse at 12.08 GHz has been obtained in the simulation. The power conversion efficiency is about 30%.« less

Space environmental effects on spacecraft: LEO materials selection guide, part 2

NASA Astrophysics Data System (ADS)

Silverman, Edward M.

1995-08-01

This document provides performance properties on major spacecraft materials and subsystems that have been exposed to the low-Earth orbit (LEO) space environment. Spacecraft materials include metals, polymers, composites, white and black paints, thermal-control blankets, adhesives, and lubricants. Spacecraft subsystems include optical components, solar cells, and electronics. Information has been compiled from LEO short-term spaceflight experiments (e.g., space shuttle) and from retrieved satellites of longer mission durations (e.g., Long Duration Exposure Facility). Major space environment effects include atomic oxygen (AO), ultraviolet radiation, micrometeoroids and debris, contamination, and particle radiation. The main objective of this document is to provide a decision tool to designers for designing spacecraft and structures. This document identifies the space environments that will affect the performance of materials and components, e.g., thermal-optical property changes of paints due to UV exposures, AO-induced surface erosion of composites, dimensional changes due to thermal cycling, vacuum-induced moisture outgassing, and surface optical changes due to AO/UV exposures. Where appropriate, relationships between the space environment and the attendant material/system effects are identified. Part 2 covers thermal control systems, power systems, optical components, electronic systems, and applications.

Space environmental effects on spacecraft: LEO materials selection guide, part 2

NASA Technical Reports Server (NTRS)

Silverman, Edward M.

1995-01-01

This document provides performance properties on major spacecraft materials and subsystems that have been exposed to the low-Earth orbit (LEO) space environment. Spacecraft materials include metals, polymers, composites, white and black paints, thermal-control blankets, adhesives, and lubricants. Spacecraft subsystems include optical components, solar cells, and electronics. Information has been compiled from LEO short-term spaceflight experiments (e.g., space shuttle) and from retrieved satellites of longer mission durations (e.g., Long Duration Exposure Facility). Major space environment effects include atomic oxygen (AO), ultraviolet radiation, micrometeoroids and debris, contamination, and particle radiation. The main objective of this document is to provide a decision tool to designers for designing spacecraft and structures. This document identifies the space environments that will affect the performance of materials and components, e.g., thermal-optical property changes of paints due to UV exposures, AO-induced surface erosion of composites, dimensional changes due to thermal cycling, vacuum-induced moisture outgassing, and surface optical changes due to AO/UV exposures. Where appropriate, relationships between the space environment and the attendant material/system effects are identified. Part 2 covers thermal control systems, power systems, optical components, electronic systems, and applications.

Minimally invasive positioning robot system of femoral neck hollow screw implants based on x-ray error correction

NASA Astrophysics Data System (ADS)

Zou, Yunpeng; Xu, Ying; Hu, Lei; Guo, Na; Wang, Lifeng

2017-01-01

Aiming the high failure rate, the high radiation quantity and the poor positioning accuracy of femoral neck traditional surgery, this article develops a set of new positioning robot system of femoral neck hollow screw implants based on X-rays error correction, which bases on the study of x-rays perspective principle and the Motion Principle of 6 DOF(degree of freedom) series robot UR(Universal Robots). Compared with Computer Assisted Navigation System, this system owns better positioning accuracy and more simple operation. In addition, without extra Equipment of Visual Tracking, this system can reduce a lot of cost. During the surgery, Doctor can plan the operation path and the pose of mark needle according to the positive and lateral X-rays images of patients. Then they can calculate the pixel ratio according to the ratio of the actual length of mark line and the length on image. After that, they can calculate the amount of exercise of UR Robot according to the relative position between operation path and guide pin and the fixed relationship between guide pin and UR robot. Then, they can control UR to drive the positioning guide pin to the operation path. At this point, check the positioning guide pin and the planning path is coincident, if not, repeat the previous steps, until the positioning guide pin and the planning path coincide which will eventually complete the positioning operation. Moreover, to verify the positioning accuracy, this paper make an errors analysis aiming to thirty cases of the experimental model of bone. The result shows that the motion accuracy of the UR Robot is 0.15mm and the Integral error precision is within 0.8mm. To verify the clinical feasibility of this system, this article analysis on three cases of the clinical experiment. In the whole process of positioning, the X-rays irradiation time is 2-3s, the number of perspective is 3-5 and the whole positioning time is 7-10min. The result shows that this system can complete accurately femoral neck positioning surgery. Meanwhile, it can greatly reduce the X-rays radiation of medical staff and patients. To summarize, it has a significant value in clinical application.

The future of image-guided radiotherapy will be MR guided

PubMed Central

Wen, Zhifei; Sadagopan, Ramaswamy; Wang, Jihong; Ibbott, Geoffrey S

2017-01-01

Advances in image-guided radiotherapy (RT) have allowed for dose escalation and more precise radiation treatment delivery. Each decade brings new imaging technologies to help improve RT patient setup. Currently, the most frequently used method of three-dimensional pre-treatment image verification is performed with cone beam CT. However, more recent developments have provided RT with the ability to have on-board MRI coupled to the teleradiotherapy unit. This latest tool for treating cancer is known as MR-guided RT. Several varieties of these units have been designed and installed in centres across the globe. Their prevalence, history, advantages and disadvantages are discussed in this review article. In preparation for the next generation of image-guided RT, this review also covers where MR-guided RT might be heading in the near future. PMID:28256898

Real-time tracking of respiratory-induced tumor motion by dose-rate regulation

NASA Astrophysics Data System (ADS)

Han-Oh, Yeonju Sarah

We have developed a novel real-time tumor-tracking technology, called Dose-Rate-Regulated Tracking (DRRT), to compensate for tumor motion caused by breathing. Unlike other previously proposed tumor-tracking methods, this new method uses a preprogrammed dynamic multileaf collimator (MLC) sequence in combination with real-time dose-rate control. This new scheme circumvents the technical challenge in MLC-based tumor tracking, that is to control the MLC motion in real time, based on real-time detected tumor motion. The preprogrammed MLC sequence describes the movement of the tumor, as a function of breathing phase, amplitude, or tidal volume. The irregularity of tumor motion during treatment is handled by real-time regulation of the dose rate, which effectively speeds up or slows down the delivery of radiation as needed. This method is based on the fact that all of the parameters in dynamic radiation delivery, including MLC motion, are enslaved to the cumulative dose, which, in turn, can be accelerated or decelerated by varying the dose rate. Because commercially available MLC systems do not allow the MLC delivery sequence to be modified in real time based on the patient's breathing signal, previously proposed tumor-tracking techniques using a MLC cannot be readily implemented in the clinic today. By using a preprogrammed MLC sequence to handle the required motion, the task for real-time control is greatly simplified. We have developed and tested the pre- programmed MLC sequence and the dose-rate regulation algorithm using lung-cancer patients breathing signals. It has been shown that DRRT can track the tumor with an accuracy of less than 2 mm for a latency of the DRRT system of less than 0.35 s. We also have evaluated the usefulness of guided breathing for DRRT. Since DRRT by its very nature can compensate for breathing-period changes, guided breathing was shown to be unnecessary for real-time tracking when using DRRT. Finally, DRRT uses the existing dose-rate control system that is provided for current linear accelerators. Therefore, DRRT can be achieved with minimal modification of existing technology, and this can shorten substantially the time necessary to establish DRRT in clinical practice.

Ultrasound-Guided Treatment of Peripheral Nerve Pathology.

PubMed

Dettori, Nathan; Choudur, Hema; Chhabra, Avneesh

2018-07-01

High-resolution ultrasound serves as a fast, accessible, reliable, and radiation-free tool for anatomical and dynamic evaluation of various peripheral nerves. It can be used not only to identify and diagnose peripheral nerve and perineural pathology accurately but also to guide various nerve and perineural interventions. We describe the normal and pathologic appearances of peripheral nerves, the pathologies commonly affecting the individual peripheral nerves, and the current ultrasound-guided peripheral nerve interventions and techniques. Future directions are also highlighted. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

In vivo reproducibility of robotic probe placement for an integrated US-CT image-guided radiation therapy system

NASA Astrophysics Data System (ADS)

Lediju Bell, Muyinatu A.; Sen, H. Tutkun; Iordachita, Iulian; Kazanzides, Peter; Wong, John

2014-03-01

Radiation therapy is used to treat cancer by delivering high-dose radiation to a pre-defined target volume. Ultrasound (US) has the potential to provide real-time, image-guidance of radiation therapy to identify when a target moves outside of the treatment volume (e.g. due to breathing), but the associated probe-induced tissue deformation causes local anatomical deviations from the treatment plan. If the US probe is placed to achieve similar tissue deformations in the CT images required for treatment planning, its presence causes streak artifacts that will interfere with treatment planning calculations. To overcome these challenges, we propose robot-assisted placement of a real ultrasound probe, followed by probe removal and replacement with a geometrically-identical, CT-compatible model probe. This work is the first to investigate in vivo deformation reproducibility with the proposed approach. A dog's prostate, liver, and pancreas were each implanted with three 2.38-mm spherical metallic markers, and the US probe was placed to visualize the implanted markers in each organ. The real and model probes were automatically removed and returned to the same position (i.e. position control), and CT images were acquired with each probe placement. The model probe was also removed and returned with the same normal force measured with the real US probe (i.e. force control). Marker positions in CT images were analyzed to determine reproducibility, and a corollary reproducibility study was performed on ex vivo tissue. In vivo results indicate that tissue deformations with the real probe were repeatable under position control for the prostate, liver, and pancreas, with median 3D reproducibility of 0.3 mm, 0.3 mm, and 1.6 mm, respectively, compared to 0.6 mm for the ex vivo tissue. For the prostate, the mean 3D tissue displacement errors between the real and model probes were 0.2 mm under position control and 0.6 mm under force control, which are both within acceptable radiotherapy treatment margins. The 3D displacement errors between the real and model probes were less acceptable for the liver and pancreas (4.1-6.1 mm), and force control maintained poorer reproducibility than position control.

Fluoroscopically Guided Interventional Procedures: A Review of Radiation Effects on Patients’ Skin and Hair

DTIC Science & Technology

2010-02-01

subsequent research has yielded additional in- sights. This review is a consensus report of current scien- tifi c data. Expected skin reactions for an...table has been cited and reproduced Essentials The minimum radiation dose n causing a specifi c type of reac- tion in the skin or hair is best...expressed in terms of a range of doses, rather than a single threshold dose. The times of onset and resolution n of specifi c radiation injuries

Practical question-and-answer guide on VDTS (video display terminals) for BEES (base bioenvironmental engineer). Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olson, B.M.

1985-01-01

The USAF OEHL conducted an extensive literature review of Video Display Terminals (VDTs) and the health problems commonly associated with them. The report is presented in a question-and-answer format in an attempt to paraphrase the most commonly asked questions about VDTs that are forwarded to USAF OEHL/RZN. The questions and answers have been divided into several topic areas: Ionizing Radiation; Nonionizing Radiation; Optical Radiation; Ultrasound; Static Electricity; Health Complaints/Ergonomics; Pregnancy.

Improving Performance During Image-Guided Procedures

PubMed Central

Duncan, James R.; Tabriz, David

2015-01-01

Objective Image-guided procedures have become a mainstay of modern health care. This article reviews how human operators process imaging data and use it to plan procedures and make intraprocedural decisions. Methods A series of models from human factors research, communication theory, and organizational learning were applied to the human-machine interface that occupies the center stage during image-guided procedures. Results Together, these models suggest several opportunities for improving performance as follows: 1. Performance will depend not only on the operator’s skill but also on the knowledge embedded in the imaging technology, available tools, and existing protocols. 2. Voluntary movements consist of planning and execution phases. Performance subscores should be developed that assess quality and efficiency during each phase. For procedures involving ionizing radiation (fluoroscopy and computed tomography), radiation metrics can be used to assess performance. 3. At a basic level, these procedures consist of advancing a tool to a specific location within a patient and using the tool. Paradigms from mapping and navigation should be applied to image-guided procedures. 4. Recording the content of the imaging system allows one to reconstruct the stimulus/response cycles that occur during image-guided procedures. Conclusions When compared with traditional “open” procedures, the technology used during image-guided procedures places an imaging system and long thin tools between the operator and the patient. Taking a step back and reexamining how information flows through an imaging system and how actions are conveyed through human-machine interfaces suggest that much can be learned from studying system failures. In the same way that flight data recorders revolutionized accident investigations in aviation, much could be learned from recording video data during image-guided procedures. PMID:24921628

Image-guided radiation therapy in lymphoma management

PubMed Central

Eng, Tony

2015-01-01

Image-guided radiation therapy (IGRT) is a process of incorporating imaging techniques such as computed tomography (CT), magnetic resonance imaging (MRI), Positron emission tomography (PET), and ultrasound (US) during radiation therapy (RT) to improve treatment accuracy. It allows real-time or near real-time visualization of anatomical information to ensure that the target is in its position as planned. In addition, changes in tumor volume and location due to organ motion during treatment can be also compensated. IGRT has been gaining popularity and acceptance rapidly in RT over the past 10 years, and many published data have been reported on prostate, bladder, head and neck, and gastrointestinal cancers. However, the role of IGRT in lymphoma management is not well defined as there are only very limited published data currently available. The scope of this paper is to review the current use of IGRT in the management of lymphoma. The technical and clinical aspects of IGRT, lymphoma imaging studies, the current role of IGRT in lymphoma management and future directions will be discussed. PMID:26484299

Dielectric image line groove antennas for millimeterwaves

NASA Astrophysics Data System (ADS)

Solbach, K.; Wolff, I.

Grooves in the ground plane of dielectric image lines are proposed as a new radiating structure. A figure is included showing the proposed groove structure as a discontinuity in a dielectric image line. A wave incident on the dielectric image line is partly reflected by the discontinuity, partly transmitted across the groove, and partly radiated into space above the line. In a travelling-wave antenna, a number of grooves are arranged below a dielectric guide, with spacings around one guide wavelength to produce a beam in the upper half space. A prescribed aperture distribution can be effected by tapering the series radiation resistance of the grooves. This can be done by adjusting the depths of the grooves with a constant width or by varying the widths of the grooves with a constant depth. Attention is also given to circular grooves. Here, the widths of the holes are chosen so that they can be considered as waveguides operating far below the cut-off frequency of the fundamental circular waveguide mode.

Gap maps and intrinsic diffraction losses in one-dimensional photonic crystal slabs.

PubMed

Gerace, Dario; Andreani, Lucio Claudio

2004-05-01

A theoretical study of photonic bands for one-dimensional (1D) lattices embedded in planar waveguides with strong refractive index contrast is presented. The approach relies on expanding the electromagnetic field on the basis of guided modes of an effective waveguide, and on treating the coupling to radiative modes by perturbation theory. Photonic mode dispersion, gap maps, and intrinsic diffraction losses of quasi guided modes are calculated for the case of self-standing membranes as well as for silicon-on-insulator structures. Photonic band gaps in a waveguide are found to depend strongly on the core thickness and on polarization, so that the gaps for transverse electric and transverse magnetic modes most often do not overlap. Radiative losses of quasiguided modes above the light line depend in a nontrivial way on structure parameters, mode index, and wave vector. The results of this study may be useful for the design of integrated 1D photonic structures with low radiative losses.

Towards image-guided atrial septal defect repair: an ex vivo analysis

NASA Astrophysics Data System (ADS)

Kwartowitz, David M.; Mefleh, Fuad N.; Baker, George H.

2012-02-01

The use of medical images in the operating room for navigation and planning is well established in many clinical disciplines. In cardiology, the use of fluoroscopy for the placement of catheters within the heart has become the standard of care. While fluoroscopy provides a live video sequence with the current location, it poses risks the patient and clinician through exposure to radiation. Radiation dose is cumulative and thus children are at even greater risk from exposure. To reduce the use of radiation, and improve surgical technique we have begun development of an image-guided navigation system, which can deliver therapeutic devices via catheter. In this work we have demonstrated the intrinsic properties of our imaging system, which have led to the development of a phantom emulating a childs heart with an ASD. Further investigation into the use of this information, in a series of mock clinical experiments, will be performed to design procedures for inserting devices into the heart while minimizing fluoroscopy use.

A method for improving the light intensity distribution in dental light-curing units.

PubMed

Arikawa, Hiroyuki; Takahashi, Hideo; Minesaki, Yoshito; Muraguchi, Kouichi; Matsuyama, Takashi; Kanie, Takahito; Ban, Seiji

2011-01-01

A method for improving the uniformity of the radiation light from dental light-curing units (LCUs), and the effect on the polymerization of light-activated composite resin are investigated. Quartz-tungsten halogen, plasma-arc, and light-emitting diode LCUs were used, and additional optical elements such as a mixing tube and diffusing screen were employed to reduce the inhomogeneity of the radiation light. The distribution of the light intensity from the light guide tip was measured across the guide tip, as well as the distribution of the surface hardness of the light-activated resin emitted with the LCUs. Although the additional optical elements caused 13.2-25.9% attenuation of the light intensity, the uniformity of the light intensity of the LCUs was significantly improved in the modified LCUs, and the uniformity of the surface hardness of the resin was also improved. Our results indicate that the addition of optical elements to the LCU may be a simple and effective method for reducing inhomogeneity in radiation light from the LCUs.

How feasible is remote 3D dosimetry for MR guided Radiation Therapy (MRgRT)?

NASA Astrophysics Data System (ADS)

Mein, S.; Rankine, L.; Miles, D.; Juang, T.; Cai, B.; Curcuru, A.; Mutic, S.; Fenoli, J.; Adamovics, J.; Li, H.; Oldham, M.

2017-05-01

To develop and apply a remote dosimetry protocol with PRESAGE® radiochromic plastic and optical-CT readout in the validation of MRI guided radiation therapy (MRgRT) treatments (MRIdian® by ViewRay®). Through multi-institutional collaboration we performed PRESAGE® dosimetry studies in 4ml cuvettes to investigate dose-response linearity, MR-compatibility, and energy-independence. An open calibration field and symmetrical 3-field plans were delivered to 10cm diameter PRESAGE® to examine percent depth dose and response uniformity under a magnetic field. Evidence of non-linear dose response led to a large volume PRESAGE® study where small corrections were developed for temporally- and spatially-dependent behaviors observed between irradiation and delayed readout. TG-119 plans were created in the MRIdian® TPS and then delivered to 14.5cm 2kg PRESAGE® dosimeters. Through the domestic investigation of an off-site MRgRT system, a refined 3D remote dosimetry protocol is presented capable of validation of advanced MRgRT radiation treatments.

Field analysis of the Cerenkov doubling of infrared coherent radiation utilizing an organic crystal core bounded by a glass capillary

NASA Astrophysics Data System (ADS)

Hayata, K.; Yanagawa, K.; Koshiba, M.

1990-12-01

A mode field analysis is presented of the second-harmonic electromagnetic wave that radiates from a nonlinear core bounded by a dielectric cladding. With this analysis the ultimate performance of the organic crystal-cored single-mode optical fiber waveguide as a guided-wave frequency doubler is evaluated through the solution of nonlinear parametric equations derived from Maxwell's equations under some assumptions. As a phase-matching scheme, a Cerenkov approach is considered because of advantages in actual device applications, in which the phase matching is achievable between the fundamental guided LP01 mode and the second-harmonic radiation (leaky) mode. Calculated results for organic cores made of benzil, 4-(N,N-dimethyl-amino)-3-acetamidonitrobenzen, 2-methyl-4-nitroaniline, and 4'-nitrobenzilidene-3-acetoamino-4-metxianiline provide useful data for designing an efficient fiber-optic wavelength converter utilizing nonlinear parametric processes. A detailed comparison is made between results for infinite and finite cladding thicknesses.

Organ motion due to respiration: the state of the art and applications in interventional radiology and radiation oncology

NASA Astrophysics Data System (ADS)

Cleary, Kevin R.; Mulcahy, Maureen; Piyasena, Rohan; Zhou, Tong; Dieterich, Sonja; Xu, Sheng; Banovac, Filip; Wong, Kenneth H.

2005-04-01

Tracking organ motion due to respiration is important for precision treatments in interventional radiology and radiation oncology, among other areas. In interventional radiology, the ability to track and compensate for organ motion could lead to more precise biopsies for applications such as lung cancer screening. In radiation oncology, image-guided treatment of tumors is becoming technically possible, and the management of organ motion then becomes a major issue. This paper will review the state-of-the-art in respiratory motion and present two related clinical applications. Respiratory motion is an important topic for future work in image-guided surgery and medical robotics. Issues include how organs move due to respiration, how much they move, how the motion can be compensated for, and what clinical applications can benefit from respiratory motion compensation. Technology that can be applied for this purpose is now becoming available, and as that technology evolves, the subject will become an increasingly interesting and clinically valuable topic of research.

CASTLE BRAVO: Fifty Years of Legend and Lore. A Guide to Off-Site Radiation Exposures

DTIC Science & Technology

2013-01-31

Radiological Surveys ............................................................... 90 4.2 The HASL Fixed Instrument Network...87 Figure 4-1. The radiation survey party comes ashore on Rongelap Island, 20 April 1954 .......... 89 Figure 4-2. The task... survey party from the USS Nicholas (DDE-449) lands at Rongelap Island. Note anticontamination booties worn over shoes. 9 March 1954

RT-06GAMMA KNIFE SURGERY AFTER NAVIGATION-GUIDED ASPIRATION FOR CYSTIC METASTATIC BRAIN TUMORS

PubMed Central

Chiba, Yasuyoshi; Mori, Kanji; Toyota, Shingo; Kumagai, Tetsuya; Yamamoto, Shota; Sugano, Hirofumi; Taki, Takuyu

2014-01-01

Metastatic brain tumors over 3 cm in diameter (volume of 14.1ml) are generally considered poor candidates for Gamma Knife surgery (GKS). We retrospectively assessed the method and efficacy of GKS for large cystic metastatic brain tumors after navigation-guided aspiration under local anesthesia. From September 2007 to April 2014, 38 cystic metastatic brain tumors in 32 patients (12 males, 20 females; mean age, 63.2 years) were treated at Kansai Rosai Hospital. The patients were performed navigation-guided cyst aspiration under local anesthesia, then at the day or the next day, were performed GKS and usually discharged on the day. The methods for preventing of leptomeningeal dissemination are following: 1) puncture from the place whose cerebral thickness is 1 cm or more; 2) avoidance of Ommaya reservoir implantation; and 3) placement of absorbable gelatin sponge to the tap tract. Tumor volume, including the cystic component, decreased from 25.4 ml (range 8.7-84.7 ml) to 11.4 ml (range 2.9-36.7 ml) following aspiration; the volume reduction was approximately 51.6%. Follow-up periods in the study population ranged from 0 to 24 months (median 3.5 months). The overall median survival was 6.7 months. There was no leptomeningeal dissemination related to the aspiration. One patient experienced radiation necrosis after GKS, one patient experienced re-aspiration by failure of aspiration, and two patients experienced surgical resections and one patient experienced re-aspiration by cyst regrowth after GKS. Long-term hospitalization is not desirable for the patients with brain metastases. In japan, Long-term hospitalization is required for surgical resection or whole brain radiation therapy, but only two days hospitalization is required for GKS after navigation-guided aspiration at our hospital. This GKS after navigation-guided aspiration is more effective and less invasive than surgical resection or whole brain radiation therapy.

Intervention Planning Using a Laser Navigation System for CT-Guided Interventions: A Phantom and Patient Study

PubMed Central

Lee, Clara; Bolck, Jan; Naguib, Nagy N.N.; Schulz, Boris; Eichler, Katrin; Aschenbach, Rene; Wichmann, Julian L.; Vogl, Thomas. J.; Zangos, Stephan

2015-01-01

Objective To investigate the accuracy, efficiency and radiation dose of a novel laser navigation system (LNS) compared to those of free-handed punctures on computed tomography (CT). Materials and Methods Sixty punctures were performed using a phantom body to compare accuracy, timely effort, and radiation dose of the conventional free-handed procedure to those of the LNS-guided method. An additional 20 LNS-guided interventions were performed on another phantom to confirm accuracy. Ten patients subsequently underwent LNS-guided punctures. Results The phantom 1-LNS group showed a target point accuracy of 4.0 ± 2.7 mm (freehand, 6.3 ± 3.6 mm; p = 0.008), entrance point accuracy of 0.8 ± 0.6 mm (freehand, 6.1 ± 4.7 mm), needle angulation accuracy of 1.3 ± 0.9° (freehand, 3.4 ± 3.1°; p < 0.001), intervention time of 7.03 ± 5.18 minutes (freehand, 8.38 ± 4.09 minutes; p = 0.006), and 4.2 ± 3.6 CT images (freehand, 7.9 ± 5.1; p < 0.001). These results show significant improvement in 60 punctures compared to freehand. The phantom 2-LNS group showed a target point accuracy of 3.6 ± 2.5 mm, entrance point accuracy of 1.4 ± 2.0 mm, needle angulation accuracy of 1.0 ± 1.2°, intervention time of 1.44 ± 0.22 minutes, and 3.4 ± 1.7 CT images. The LNS group achieved target point accuracy of 5.0 ± 1.2 mm, entrance point accuracy of 2.0 ± 1.5 mm, needle angulation accuracy of 1.5 ± 0.3°, intervention time of 12.08 ± 3.07 minutes, and used 5.7 ± 1.6 CT-images for the first experience with patients. Conclusion Laser navigation system improved accuracy, duration of intervention, and radiation dose of CT-guided interventions. PMID:26175571

Acoustically trapped colloidal crystals that are reconfigurable in real time

PubMed Central

Caleap, Mihai; Drinkwater, Bruce W.

2014-01-01

Photonic and phononic crystals are metamaterials with repeating unit cells that result in internal resonances leading to a range of wave guiding and filtering properties and are opening up new applications such as hyperlenses and superabsorbers. Here we show the first, to our knowledge, 3D colloidal phononic crystal that is reconfigurable in real time and demonstrate its ability to rapidly alter its frequency filtering characteristics. Our reconfigurable material is assembled from microspheres in aqueous solution, trapped with acoustic radiation forces. The acoustic radiation force is governed by an energy landscape, determined by an applied high-amplitude acoustic standing wave field, in which particles move swiftly to energy minima. This creates a colloidal crystal of several milliliters in volume with spheres arranged in an orthorhombic lattice in which the acoustic wavelength is used to control the lattice spacing. Transmission acoustic spectroscopy shows that the new colloidal crystal behaves as a phononic metamaterial and exhibits clear band-pass and band-stop frequencies which are adjusted in real time. PMID:24706925

Experimental Results From a 2kW Brayton Power Conversion Unit

NASA Technical Reports Server (NTRS)

Hervol, David; Mason, Lee; Birchenough, Arthur

2003-01-01

This paper presents experimental test results from operation of a 2 kWe Brayton power conversion unit. The Brayton converter was developed for a solar dynamic power system flight experiment planned for the Mir Space Station in 1997. The flight experiment was cancelled, but the converter was tested at Glenn Research Center as part of the Solar Dynamic Ground Test Demonstration system which included a solar concentrator, heat receiver, and space radiator. In preparation for the current testing, the heat receiver was removed and replaced with an electrical resistance heater, simulating the thermal input of a steady-state nuclear source. The converter was operated over a full range of thermal input power levels and rotor speeds to generate an overall performance map. The converter unit will serve as the centerpiece of a Nuclear Electric Propulsion Testbed at Glenn. Future potential uses for the Testbed include high voltage electrical controller development, integrated electric thruster testing and advanced radiator demonstration testing to help guide high power Brayton technology development for Nuclear Electric Propulsion (NEP).

Big Data Analytics for Prostate Radiotherapy.

PubMed

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

2016-01-01

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

Big Data Analytics for Prostate Radiotherapy

PubMed Central

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

2016-01-01

Radiation therapy is a first-line treatment option for localized prostate cancer and radiation-induced normal tissue damage are often the main limiting factor for modern radiotherapy regimens. Conversely, under-dosing of target volumes in an attempt to spare adjacent healthy tissues limits the likelihood of achieving local, long-term control. Thus, the ability to generate personalized data-driven risk profiles for radiotherapy outcomes would provide valuable prognostic information to help guide both clinicians and patients alike. Big data applied to radiation oncology promises to deliver better understanding of outcomes by harvesting and integrating heterogeneous data types, including patient-specific clinical parameters, treatment-related dose–volume metrics, and biological risk factors. When taken together, such variables make up the basis for a multi-dimensional space (the “RadoncSpace”) in which the presented modeling techniques search in order to identify significant predictors. Herein, we review outcome modeling and big data-mining techniques for both tumor control and radiotherapy-induced normal tissue effects. We apply many of the presented modeling approaches onto a cohort of hypofractionated prostate cancer patients taking into account different data types and a large heterogeneous mix of physical and biological parameters. Cross-validation techniques are also reviewed for the refinement of the proposed framework architecture and checking individual model performance. We conclude by considering advanced modeling techniques that borrow concepts from big data analytics, such as machine learning and artificial intelligence, before discussing the potential future impact of systems radiobiology approaches. PMID:27379211

SU-E-J-211: Design and Study of In-House Software Based Respiratory Motion Monitoring, Controlling and Breath-Hold Device for Gated Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shanmugam, Senthilkumar

Purpose: The purpose of this present work was to fabricate an in-house software based respiratory monitoring, controlling and breath-hold device using computer software programme which guides the patient to have uniform breath hold in response to request during the gated radiotherapy. Methods: The respiratory controlling device consists of a computer, inhouse software, video goggles, a highly sensitive sensor for measurement of distance, mounting systems, a camera, a respiratory signal device, a speaker and a visual indicator. The computer is used to display the respiratory movements of the patient with digital as well as analogue respiration indicators during the respiration cycle,more » to control, breath-hold and analyze the respiratory movement using indigenously developed software. Results: Studies were conducted with anthropomophic phantoms by simulating the respiratory motion on phantoms and recording the respective movements using the respiratory monitoring device. The results show good agreement between the simulated and measured movements. Further studies were conducted for 60 cancer patients with several types of cancers in the thoracic region. The respiratory movement cycles for each fraction of radiotherapy treatment were recorded and compared. Alarm indications are provided in the system to indicate when the patient breathing movement exceeds the threshold level. This will help the patient to maintain uniform breath hold during the radiotherapy treatment. Our preliminary clinical test results indicate that our device is highly reliable and able to maintain the uniform respiratory motion and breathe hold during the entire course of gated radiotherapy treatment. Conclusion: An indigenous respiratory monitoring device to guide the patient to have uniform breath hold device was fabricated. The alarm feature and the visual waveform indicator in the system guide the patient to have normal respiration. The signal from the device can be connected to the radiation unit in near future to carry out the gated radiotherapy treatment.« less

Nonmelanoma skin cancer in mountain guides: high prevalence and lack of awareness warrant development of evidence-based prevention tools.

PubMed

Zink, Alexander; Koch, Elisabeth; Seifert, Florian; Rotter, Markus; Spinner, Christoph D; Biedermann, Tilo

2016-01-01

Nonmelanoma skin cancer (NMSC) is the most common cancer in Switzerland and Europe. The main causative factor is exposure to ultraviolet radiation, which puts outdoor workers in general at a higher risk of developing NMSC than indoor workers. However, few studies have clinically examined the risk of developing NMSC to outdoor workers, especially mountain guides. We aimed to investigate the prevalence of NMSC and corresponding precancerous lesions, and the associated risk behaviour of mountain and ski guides in order to develop future prevention programmes. We conducted a cross-sectional study including mountain and ski guides from southern Germany, who underwent a full-body skin check-up by a dermatologist. We assessed their NMSC awareness and risk behaviour using a paper-based questionnaire. Of the 62 state-certified mountain and ski guides (55 men, 7 women; mean age 52.9 ± 13.4 years) included in this study, 27 (43.5%) were diagnosed with NMSC or its premalignant stages. In addition, 59.7% of the participants expressed the opinion that their protection from ultraviolet radiation exposure needs to be improved; 83.6% requested further information on NMSC, and 48.5% had never undergone a skin check-up or consulted a dermatologist before. Mountain and ski guides are at a high risk for developing NMSC. Their unmet medical needs indicate an underestimation of NMSC prevalence, which is usually based on reports by insurance companies, and offer the chance for developing evidence-based awareness and prevention tools that can be promoted to individuals with other outdoor jobs.

Theory of topological insulator waveguides: polarization control and the enhancement of the magneto-electric effect

NASA Astrophysics Data System (ADS)

Crosse, J. A.

2017-02-01

Topological insulators subject to a time-reversal-symmetry-breaking perturbation are predicted to display a magneto-electric effect that causes the electric and magnetic induction fields to mix at the material’s surface. This effect induces polarization rotations of between ≈1-10 mrad per interface in an incident plane-polarized electromagnetic wave normal to a multilayered structure. Here we show, theoretically and numerically, that by using a waveguide geometry with a topological insulator guide layer and magneto-dielectric cladding it is possible to achieve rotations of ≈100 mrad and generate an elliptical polarization with only a three-layered structure. This geometry is beneficial, not only as a way to enhance the magneto-electric effect, rendering it easier to observe, but also as a method for controlling the polarization of electromagnetic radiation.

Biomarker-guided screening of Juzen-taiho-to, an Oriental herbal formulation for immmunostimulation

PubMed Central

Takaoka, Anna; Iacovidou, Maria; Hasson, Tal H.; Montenegro, Diego; Li, Xiangming; Tsuji, Moriya; Kawamura, Akira

2014-01-01

Juzen-taiho-to (JTT) is an immunostimulatory herbal formulation that is clinically used in East Asia for cancer patients undergoing chemotherapy and radiation. The formulation stimulates various leukocytes, including T, B, and NK cells and macrophages (MΦ). Although JTT is known to contain numerous compounds with various pharmacological activities, it is not clear which compounds are responsible for the stimulation of individual cell types. Here, we conducted what we call, “biomarker-guided screening,” to purify compounds responsible for the MΦ stimulatory activity. To this end, gene expression was analyzed by a DNA array for MΦ treated with JTT and DMSO (vehicle control), which identified intercellular adhesion molecule 1 (ICAM-1) as a biomarker of MΦ-stimulation by JTT. A qRT-PCR assay of ICAM-1 was then used to guide the purification of active compounds. The screening resulted in the purification of a glycolipid mixture, containing β-glucosylceramides. The glycolipid mixture potently stimulated ICAM-1 expression in primary dendritic cells (DC) as well as in primary CD14+ (MΦ) cells. Identification of this glycolipid mixture opens an opportunity for further studies to understand how plant-derived glycolipids stimulate MΦ and DC in a safe and effective manner as demonstrated by JTT. PMID:24549928

[Prospective economic evaluation of image-guided radiation therapy for prostate cancer in the framework of the national programme for innovative and costly therapies assessment].

PubMed

Pommier, P; Morelle, M; Perrier, L; de Crevoisier, R; Laplanche, A; Dudouet, P; Mahé, M-A; Chauvet, B; Nguyen, T-D; Créhange, G; Zawadi, A; Chapet, O; Latorzeff, I; Bossi, A; Beckendorf, V; Touboul, E; Muracciole, X; Bachaud, J-M; Supiot, S; Lagrange, J-L

2012-09-01

The main objective of the economical study was to prospectively and randomly assess the additional costs of daily versus weekly patient positioning quality control in image-guided radiotherapy (IGRT), taking into account the modalities of the 3D-imaging: tomography (CBCT) or gold seeds implants. A secondary objective was to prospectively assess the additional costs of 3D versus 2D imaging with portal imaging for patient positioning controls. Economics data are issued from a multicenter randomized medico-economics trial comparing the two frequencies of patient positioning control during prostate IGRT. A prospective cohort with patient positioning control with PI (control group) was constituted for the cost comparison between 3D (IGRT) versus 2D imaging. The economical evaluation was focused to the radiotherapy direct costs, adopting the hospital's point of view and using a microcosting method applied to the parameters that may lead to cost differences between evaluated strategies. The economical analysis included a total of 241 patients enrolled between 2007 and 2011 in seven centres, 183 in the randomized study (128 with CBCT and 55 with fiducial markers) and 58 in the control group. Compared to weekly controls, the average additional cost per patient of daily controls was €847 (CBCT) and €179 (markers). Compared to PI, the average additional cost per patient was €1392 (CBCT) and €997 (fiducial markers) for daily controls; €545 (CBCT) and €818 (markers) in case of weekly controls. A daily frequency for image control in IGRT and 3D images patient positioning control (IGRT) for prostate cancer lead to significant additional cost compared to weekly control and 2D imaging (PI). Long-term clinical assessment will permit to assess the medico-economical ratio of these innovative radiotherapy modalities. Copyright © 2012 Société française de radiothérapie oncologique (SFRO). Published by Elsevier SAS. All rights reserved.

Stereotactic Body Radiation Therapy Delivery in a Genetically Engineered Mouse Model of Lung Cancer.

PubMed

Du, Shisuo; Lockamy, Virginia; Zhou, Lin; Xue, Christine; LeBlanc, Justin; Glenn, Shonna; Shukla, Gaurav; Yu, Yan; Dicker, Adam P; Leeper, Dennis B; Lu, You; Lu, Bo

2016-11-01

To implement clinical stereotactic body radiation therapy (SBRT) using a small animal radiation research platform (SARRP) in a genetically engineered mouse model of lung cancer. A murine model of multinodular Kras-driven spontaneous lung tumors was used for this study. High-resolution cone beam computed tomography (CBCT) imaging was used to identify and target peripheral tumor nodules, whereas off-target lung nodules in the contralateral lung were used as a nonirradiated control. CBCT imaging helps localize tumors, facilitate high-precision irradiation, and monitor tumor growth. SBRT planning, prescription dose, and dose limits to normal tissue followed the guidelines set by RTOG protocols. Pathologic changes in the irradiated tumors were investigated using immunohistochemistry. The image guided radiation delivery using the SARRP system effectively localized and treated lung cancer with precision in a genetically engineered mouse model of lung cancer. Immunohistochemical data confirmed the precise delivery of SBRT to the targeted lung nodules. The 60 Gy delivered in 3 weekly fractions markedly reduced the proliferation index, Ki-67, and increased apoptosis per staining for cleaved caspase-3 in irradiated lung nodules. It is feasible to use the SARRP platform to perform dosimetric planning and delivery of SBRT in mice with lung cancer. This allows for preclinical studies that provide a rationale for clinical trials involving SBRT, especially when combined with immunotherapeutics. Copyright © 2016. Published by Elsevier Inc.

Ultrasound guided transarterial coil placement in the internal and external carotid artery in horses.

PubMed

Muñoz, Juan; Iglesias, Manuel; Chao, Eduardo Lloret; Bussy, Christian

2015-04-01

To assess ultrasound guided transarterial coil placement (UGTACP) for occlusion of the internal carotid artery (ICA) and external carotid artery (ECA) in horses. Cadaveric and in vivo study. Cadaveric horses (n = 10), healthy horses (3), and 1 clinical case. Cadaveric and in vivo (healthy horses): UGTACP was performed in the caudal part of the ICA and ECA. Coil placement in the rostral part of the ICA was performed blindly and controlled by conventional radiography. No coils were placed in the rostral part of the ECA. UGTACP of the ICA was in a horse with guttural pouch mycosis of the left guttural pouch. Accurate ultrasound-guided catheterization of the ICA and ECA was performed in all specimens. Ultrasound-guided coil placement was successfully performed in all cases except 1. No complications occurred in the in vivo study. The clinical case fully recovered and returned to its intended use. Based on our study, UGTACP of the ICA and ECA caudal part is a feasible alternative to fluoroscopy. An advantage of this technique is the accuracy with which you can catheterize both ICA and ECA and the ability to identify unusual branching at the origin of the ICA. Regarding the rostral part of the ICA, angiographic catheter guidance in this region is probably more precise using fluoroscopy as it is performed blindly. In a clinical situation, combination of US and fluoroscopy guidance can result in reduction of radiation exposure time. © Copyright 2014 by The American College of Veterinary Surgeons.

Occupational radiation exposure and its health effects on interventional medical workers: study protocol for a prospective cohort study.

PubMed

Ko, Seulki; Chung, Hwan Hoon; Cho, Sung Bum; Jin, Young Woo; Kim, Kwang Pyo; Ha, Mina; Bang, Ye Jin; Ha, Yae Won; Lee, Won Jin

2017-12-15

Although fluoroscopically guided procedures involve a considerably high dose of radiation, few studies have investigated the effects of radiation on medical workers involved in interventional fluoroscopy procedures. Previous research remains in the early stages and has not reached a level comparable with other occupational studies thus far. Furthermore, the study of radiation workers provides an opportunity to estimate health risks at low doses and dose rates of ionising radiation. Therefore, the objectives of this study are (1) to initiate a prospective cohort study by conducting a baseline survey among medical radiation workers who involve interventional fluoroscopy procedures and (2) to assess the effect of occupational radiation exposure and on the overall health status through an in-depth cross-sectional study. Intervention medical workers in Korea will be enrolled by using a self-administered questionnaire survey, and the survey data will be linked with radiation dosimetry data, National Health Insurance claims data, cancer registry and mortality data. After merging these data, the radiation organ dose, lifetime attributable risk due to cancer and the risk per unit dose will be estimated. For the cross-sectional study, approximately 100 intervention radiology department workers will be investigated for blood tests, clinical examinations such as ultrasonography (thyroid and carotid artery scan) and lens opacity, the validation of badge dose and biodosimetry. This study was reviewed and approved by the institutional review board of Korea University (KU-IRB-12-12-A-1). All participants will provide written informed consent prior to enrolment. The findings of the study will be disseminated through peer-reviewed scientific journals, conference presentations, and a report will be submitted to the relevant public health authorities in the Korea Centers for Disease Control and Prevention to help with the development of appropriate research and management policies. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Occupational radiation exposure and its health effects on interventional medical workers: study protocol for a prospective cohort study

PubMed Central

Ko, Seulki; Chung, Hwan Hoon; Cho, Sung Bum; Jin, Young Woo; Kim, Kwang Pyo; Ha, Mina; Bang, Ye Jin; Ha, Yae Won; Lee, Won Jin

2017-01-01

Introduction Although fluoroscopically guided procedures involve a considerably high dose of radiation, few studies have investigated the effects of radiation on medical workers involved in interventional fluoroscopy procedures. Previous research remains in the early stages and has not reached a level comparable with other occupational studies thus far. Furthermore, the study of radiation workers provides an opportunity to estimate health risks at low doses and dose rates of ionising radiation. Therefore, the objectives of this study are (1) to initiate a prospective cohort study by conducting a baseline survey among medical radiation workers who involve interventional fluoroscopy procedures and (2) to assess the effect of occupational radiation exposure and on the overall health status through an in-depth cross-sectional study. Methods and analysis Intervention medical workers in Korea will be enrolled by using a self-administered questionnaire survey, and the survey data will be linked with radiation dosimetry data, National Health Insurance claims data, cancer registry and mortality data. After merging these data, the radiation organ dose, lifetime attributable risk due to cancer and the risk per unit dose will be estimated. For the cross-sectional study, approximately 100 intervention radiology department workers will be investigated for blood tests, clinical examinations such as ultrasonography (thyroid and carotid artery scan) and lens opacity, the validation of badge dose and biodosimetry. Ethics and dissemination This study was reviewed and approved by the institutional review board of Korea University (KU-IRB-12-12-A-1). All participants will provide written informed consent prior to enrolment. The findings of the study will be disseminated through peer-reviewed scientific journals, conference presentations, and a report will be submitted to the relevant public health authorities in the Korea Centers for Disease Control and Prevention to help with the development of appropriate research and management policies. PMID:29248885

Space based astronomy: Teacher's guide with activities

NASA Technical Reports Server (NTRS)

Rosenberg, Carla B. (Editor); Weiler, Edward; Morrow, Cherilyn; Bacon, Pamela M.; Thorne, Muriel; Blanchard, Paul A.; Howard, Sethane; Pengra, Patricia R.; Brown, Deborah A.; Winrich, Ralph

1994-01-01

This curriculum guide uses hands-on activities to help students and teachers understand the significance of space-based astronomy - astronomical observations made from outer space. The guide contains few of the traditional activities found in many astronomy guides such as constellation studies, lunar phases, and planetary orbits. Instead, it tells the story of why it is important to observe celestial objects from outer space and how to study the entire electromagnetic spectrum. The guide begins with a survey of astronomy related NASA spacecraft. This is followed by a collection of activities in four units: (1) the atmospheric filter; (2) the electromagnetic spectrum; (3) collecting electromagnetic radiation; and (4) down to Earth. A curriculum index identifies the curriculum areas each activity addresses. The guide concludes with a glossary, reference list, a NASA Resources list, and an evaluation card. It is designed for students in grades 5 through 8.

Spatial frequency performance limitations of radiation dose optimization and beam positioning

NASA Astrophysics Data System (ADS)

Stewart, James M. P.; Stapleton, Shawn; Chaudary, Naz; Lindsay, Patricia E.; Jaffray, David A.

2018-06-01

The flexibility and sophistication of modern radiotherapy treatment planning and delivery methods have advanced techniques to improve the therapeutic ratio. Contemporary dose optimization and calculation algorithms facilitate radiotherapy plans which closely conform the three-dimensional dose distribution to the target, with beam shaping devices and image guided field targeting ensuring the fidelity and accuracy of treatment delivery. Ultimately, dose distribution conformity is limited by the maximum deliverable dose gradient; shallow dose gradients challenge techniques to deliver a tumoricidal radiation dose while minimizing dose to surrounding tissue. In this work, this ‘dose delivery resolution’ observation is rigorously formalized for a general dose delivery model based on the superposition of dose kernel primitives. It is proven that the spatial resolution of a delivered dose is bounded by the spatial frequency content of the underlying dose kernel, which in turn defines a lower bound in the minimization of a dose optimization objective function. In addition, it is shown that this optimization is penalized by a dose deposition strategy which enforces a constant relative phase (or constant spacing) between individual radiation beams. These results are further refined to provide a direct, analytic method to estimate the dose distribution arising from the minimization of such an optimization function. The efficacy of the overall framework is demonstrated on an image guided small animal microirradiator for a set of two-dimensional hypoxia guided dose prescriptions.

Exposure Risks Among Children Undergoing Radiation Therapy: Considerations in the Era of Image Guided Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hess, Clayton B.; Thompson, Holly M.; Benedict, Stanley H.

Recent improvements in toxicity profiles of pediatric oncology patients are attributable, in part, to advances in the field of radiation oncology such as intensity modulated radiation (IMRT) and proton therapy (IMPT). While IMRT and IMPT deliver highly conformal dose to targeted volumes, they commonly demand the addition of 2- or 3-dimensional imaging for precise positioning—a technique known as image guided radiation therapy (IGRT). In this manuscript we address strategies to further minimize exposure risk in children by reducing effective IGRT dose. Portal X rays and cone beam computed tomography (CBCT) are commonly used to verify patient position during IGRT and,more » because their relative radiation exposure is far less than the radiation absorbed from therapeutic treatment beams, their sometimes significant contribution to cumulative risk can be easily overlooked. Optimizing the conformality of IMRT/IMPT while simultaneously ignoring IGRT dose may result in organs at risk being exposed to a greater proportion of radiation from IGRT than from therapeutic beams. Over a treatment course, cumulative central-axis CBCT effective dose can approach or supersede the amount of radiation absorbed from a single treatment fraction, a theoretical increase of 3% to 5% in mutagenic risk. In select scenarios, this may result in the underprediction of acute and late toxicity risk (such as azoospermia, ovarian dysfunction, or increased lifetime mutagenic risk) in radiation-sensitive organs and patients. Although dependent on variables such as patient age, gender, weight, body habitus, anatomic location, and dose-toxicity thresholds, modifying IGRT use and acquisition parameters such as frequency, imaging modality, beam energy, current, voltage, rotational degree, collimation, field size, reconstruction algorithm, and documentation can reduce exposure, avoid unnecessary toxicity, and achieve doses as low as reasonably achievable, promoting a culture and practice of “gentle IGRT.”.« less

Master Control--How Kids Can Control the Impact of TV, and Enjoy It More Than Ever! A Classroom Guide.

ERIC Educational Resources Information Center

1994

This classroom guide and "Better Viewing" guide accompany a 28-minute videotape on television literacy called "Master Control." The classroom guide explains the purpose behind the video, pointing out that "Master Control" is not about doing away with TV, but about a youngster's getting the most out of his or her TV…

Lunar Reconnaissance Orbiter (LRO) Rapid Thermal Design Development

NASA Technical Reports Server (NTRS)

Baker, Charles; Cottingham, Christine; Garrison, Matthew; Melak, Tony; Peabody, Sharon; Powers, Dan

2009-01-01

The Lunar Reconnaissance Orbiter (LRO) project had a rapid development schedule starting with project conception in spring of 2004, instrument and launch vehicle selection late in 2005 and then launch in early 2009. The lunar thermal environment is one of the harshest in our solar system with the heavy infrared loading of the moon due to low albedo, lack of lunar atmosphere, and low effective regolith conduction. This set of constraints required a thermal design which maximized performance (minimized radiator area and cold control heater power) and minimized thermal hardware build at the orbiter level (blanketing, and heater service). The orbiter design located most of the avionics on an isothermalized heat pipe panel called the IsoThermal Panel (ITP). The ITP was coupled by dual bore heat pipes to an Optical Solar Reflector (OSR) covered heat pipe radiator. By coupling all of the avionics to one system, the hardware was simplified. The seven instruments were mainly heritage instruments which resulted in their desired radiators being located by their heritage design. This minimized instrument redesigns and therefore allowed them to be delivered earlier, though it resulted in a more complex orbiter level blanket and heater service design. Three of the instruments were mounted on a tight pointing M55J optical bench that needed to be covered in heaters to maintain pointing. Two were mounted to spacecraft controlled radiators. One was mounted to the ITP Dual Bores. The last was mounted directly to the bus structure on the moon facing panel. The propulsion system utilized four-20 pound insertion thrusters and eight-5 pound attitude control thrusters (ACS) in addition to 1000 kg of fuel in two large tanks. The propulsion system had a heater cylinder and a heated mounting deck for the insertion thrusters which coupled most of the propulsion design together simplifying the heater design. The High Gain Antenna System (HGAS) and Solar Array System (SAS) used dual axis actuator gimbal systems. HGAS required additional boom heaters to cool the approximately 10 W of RF losses thru the rotary joints and wave guides from the 40 W Ka system. By design this module needed a fair amount of heater, blanketing, and radiator complexity. The SAS system required a separate cable wrap radiator to help cool the Solar Array harness which dissipated 30 W thru the actuators and cable wraps. This module also was complex.

A Hybrid Reality Radiation-free Simulator for Teaching Wire Navigation Skills

PubMed Central

Kho, Jenniefer Y.; Johns, Brian D.; Thomas, Geb. W.; Karam, Matthew D.; Marsh, J. Lawrence; Anderson, Donald D.

2016-01-01

Objectives Surgical simulation is an increasingly important method to facilitate the acquiring of surgical skills. Simulation can be helpful in developing hip fracture fixation skills because it is a common procedure for which performance can be objectively assessed (i.e., the tip-apex distance). The procedure requires fluoroscopic guidance to drill a wire along an osseous trajectory to a precise position within bone. The objective of this study was to assess the construct validity for a novel radiation-free simulator designed to teach wire navigation skills in hip fracture fixation. Methods Novices (N=30) with limited to no surgical experience in hip fracture fixation and experienced surgeons (N=10) participated. Participants drilled a guide wire in the center-center position of a synthetic femoral head in a hip fracture simulator, using electromagnetic sensors to track the guide wire position. Sensor data were gathered to generate fluoroscopic-like images of the hip and guide wire. Simulator performance of novice and experienced participants was compared to measure construct validity. Results The simulator was able to discriminate the accuracy in guide wire position between novices and experienced surgeons. Experienced surgeons achieved a more accurate tip-apex distance than novices (13 vs 23 mm, respectively, p=0.009). The magnitude of improvement on successive simulator attempts was dependent on level of expertise; tip-apex distance improved significantly in the novice group, while it was unchanged in the experienced group. Conclusions This hybrid reality, radiation-free hip fracture simulator, which combines real-world objects with computer-generated imagery demonstrates construct validity by distinguishing the performance of novices and experienced surgeons. There is a differential effect depending on level of experience, and it could be used as an effective training tool in novice surgeons. PMID:26165262

Current and emerging treatments for brain metastases.

PubMed

Lin, Jenny; Jandial, Rahul; Nesbit, Amanda; Badie, Behnam; Chen, Mike

2015-04-01

Brain metastasis in patients with cancer can be indicative of multisystem spread or lead to neurological demise if not locally controlled, and is associated with poor survival and high morbidity. Compared with metastasis to other areas of the body, brain metastasis possesses a unique biology that confers high resistance to systemic therapies. This phenomenon has been historically attributed to the inability of chemotherapeutic agents to pass through the blood-brain barrier. Recent studies challenge this premise, revealing other potentially targetable mechanism(s). Therapies that exploit recent advances in the understanding of brain metastasis are still in early stages of development. Encouragingly, and discovered by happenstance, some molecularly targeted drugs already appear to have efficacy against certain tumors and accompanying cerebral edema. In the meantime, conventional treatment modalities such as surgery and radiation have iteratively reached new levels of refinement. However, these achievements are somewhat muted by the emergence of magnetic resonance (MR)-guided laser interstitial thermal therapy, a minimally invasive neuroablative technique. On the horizon, MR-guided focused ultrasound surgery is similarly intriguing. Even in the absence of further advances, local control is frequently achieved with state-of-the-art therapies. Dramatic improvements will likely require sophisticated approaches that account for the particular effects of the microenvironment of the central nervous system on metastasis.

Niagara Falls Storage Site annual site environmental monitoring report. Calendar year 1985

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1986-04-01

During 1985, an environmental monitoring program was continued at the Niagara Falls Storage Site (NFSS), a United States Department of Energy (DOE) surplus facility located in Niagara County, New York, presently used for the interim storage of low-level radioactive residues and contaminated soils and rubble. The monitoring program is being conducted by Bechtel National, Inc. Monitoring results show that the NFSS is in compliance with DOE concentration guides and radiation protection standards. Derived Concentration Guides (DCGs) represent the concentrations of radionuclides in air or water that would limit the radiation dose to 100 mrem/yr. The applicable limits have been revisedmore » since the 1984 environmental monitoring report was published. The limits applied in 1984 were based on a radiation protection standard of 500 mrem/yr; the limits applied for the 1985 are based on a standard of 100 mrem/yr. To determine whether the site is in compliance with DOE standards, environmental measurements are expressed as percentages of the applicable DCG, while the calculated doses to the public are expressed as percentages of the applicable radiation protection standard. The monitoring program measured radon gas concentrations in air; uranium and radium concentrations in surface water, groundwater, and sediments; and external gamma dose rates. Environmental samples collected were analyzed to determine compliance with applicable standards. Potential radiation doses to the public were also calculated.« less

Gold-coated copper cone detector as a new standard detector for F2 laser radiation at 157 nm.

PubMed

Kück, Stefan; Brandt, Friedhelm; Taddeo, Mario

2005-04-20

A new standard detector for high-accuracy measurements of F2 laser radiation at 157 nm is presented. This gold-coated copper cone detector permits the measurement of average powers up to 2 W with an uncertainty of approximately 1%. To the best of our knowledge, this is the first highly accurate standard detector for F2 laser radiation for this power level. It is fully characterized according to Guide to the Expression of Uncertainty in Measurement of the International Organization for Standardization and is connected to the calibration chain for laser radiation established by the German National Metrology Institute.

Radiation Therapy for Locally Advanced Esophageal Cancer.

PubMed

Chun, Stephen G; Skinner, Heath D; Minsky, Bruce D

2017-04-01

The treatment of locally advanced esophageal cancer is controversial. For patients who are candidates for surgical resection, multiple prospective clinical trials have demonstrated the advantages of neoadjuvant chemoradiation. For patients who are medically inoperable, definitive chemoradiation is an alternative approach with survival rates comparable to trimodality therapy. Although trials of dose escalation are ongoing, the standard radiation dose remains 50.4 Gy. Modern radiotherapy techniques such as image-guided radiation therapy with motion management and intensity-modulated radiation therapy are strongly encouraged with a planning objective to maximize conformity to the intended target volume while reducing dose delivered to uninvolved normal tissues. Copyright © 2016 Elsevier Inc. All rights reserved.

Significant Reduction of Late Toxicities in Patients With Extremity Sarcoma Treated With Image-Guided Radiation Therapy to a Reduced Target Volume: Results of Radiation Therapy Oncology Group RTOG-0630 Trial.

PubMed

Wang, Dian; Zhang, Qiang; Eisenberg, Burton L; Kane, John M; Li, X Allen; Lucas, David; Petersen, Ivy A; DeLaney, Thomas F; Freeman, Carolyn R; Finkelstein, Steven E; Hitchcock, Ying J; Bedi, Manpreet; Singh, Anurag K; Dundas, George; Kirsch, David G

2015-07-10

We performed a multi-institutional prospective phase II trial to assess late toxicities in patients with extremity soft tissue sarcoma (STS) treated with preoperative image-guided radiation therapy (IGRT) to a reduced target volume. Patients with extremity STS received IGRT with (cohort A) or without (cohort B) chemotherapy followed by limb-sparing resection. Daily pretreatment images were coregistered with digitally reconstructed radiographs so that the patient position could be adjusted before each treatment. All patients received IGRT to reduced tumor volumes according to strict protocol guidelines. Late toxicities were assessed at 2 years. In all, 98 patients were accrued (cohort A, 12; cohort B, 86). Cohort A was closed prematurely because of poor accrual and is not reported. Seventy-nine eligible patients from cohort B form the basis of this report. At a median follow-up of 3.6 years, five patients did not have surgery because of disease progression. There were five local treatment failures, all of which were in field. Of the 57 patients assessed for late toxicities at 2 years, 10.5% experienced at least one grade ≥ 2 toxicity as compared with 37% of patients in the National Cancer Institute of Canada SR2 (CAN-NCIC-SR2: Phase III Randomized Study of Pre- vs Postoperative Radiotherapy in Curable Extremity Soft Tissue Sarcoma) trial receiving preoperative radiation therapy without IGRT (P < .001). The significant reduction of late toxicities in patients with extremity STS who were treated with preoperative IGRT and absence of marginal-field recurrences suggest that the target volumes used in the Radiation Therapy Oncology Group RTOG-0630 (A Phase II Trial of Image-Guided Preoperative Radiotherapy for Primary Soft Tissue Sarcomas of the Extremity) study are appropriate for preoperative IGRT for extremity STS. © 2015 by American Society of Clinical Oncology.

Magnetic resonance spectroscopic imaging for improved treatment planning of prostate cancer

NASA Astrophysics Data System (ADS)

Venugopal, Niranjan

Prostate cancer is the most common malignancy afflicting Canadian men in 2011. Physicians use digital rectal exams (DRE), blood tests for prostate specific antigen (PSA) and transrectal ultrasound (TRUS)-guided biopsies for the initial diagnosis of prostate cancer. None of these tests detail the spatial extent of prostate cancer - information critical for using new therapies that can target cancerous prostate. With an MRI technique called proton magnetic resonance spectroscopic imaging (1H-MRSI), biochemical analysis of the entire prostate can be done without the need for biopsy, providing detailed information beyond the non-specific changes in hardness felt by an experienced urologist in a DRE, the presence of PSA in blood, or the "blind-guidance" of TRUS-guided biopsy. A hindrance to acquiring high quality 1H-MRSI data comes from signal originating from fatty tissue surrounding prostate that tends to mask or distort signal from within the prostate, thus reducing the overall clinical usefulness of 1H-MRSI data. This thesis has three major areas of focus: 1) The development of an optimized 1H-MRSI technique, called conformal voxel magnetic resonance spectroscopy (CV-MRS), to deal the with removal of unwanted lipid contaminating artifacts at short and long echo times. 2) An in vivo human study to test the CV-MRS technique, including healthy volunteers and cancer patients scheduled for radical prostatectomy or radiation therapy. 3) A study to determine the efficacy of using the 1H-MRSI data for optimized radiation treatment planning using modern delivery techniques like intensity modulated radiation treatment. Data collected from the study using the optimized CV-MRS method show significantly reduced lipid contamination resulting in high quality spectra throughout the prostate. Combining the CV-MRS technique with spectral-spatial excitation further reduced lipid contamination and opened up the possibility of detecting metabolites with short T2 relaxation times. Results from the in vivo study were verified with post-histopathological data. Lastly, 1H-MRSI data was incorporated into the radiation treatment planning software and used to assess tumour control by escalating the radiation to prostate lesions that were identified by 1H-MRSI. In summary, this thesis demonstrates the clinical feasibility of using advanced spectroscopic imaging techniques for improved diagnosis and treatment of prostate cancer.

Sign language in the CT suite: a new approach in communicating between radiologists and radiographers.

PubMed

Wang, Edward H; Sampson, Matthew J

2016-09-01

When performing CT-guided procedures or angiographic procedures, radiologists performing procedures need to communicate with radiographers at a workstation behind radiation shielding glass. As shielding renders verbal communication impossible, we have developed a set of standardised hand signals for use at our department to help us achieve clear and efficient communication between radiologists and radiographers while performing CT-guided or angiographic procedures.

Minimally Invasive Spinal Surgery with Intraoperative Image-Guided Navigation

PubMed Central

Kim, Terrence T.; Johnson, J. Patrick; Pashman, Robert; Drazin, Doniel

2016-01-01

We present our perioperative minimally invasive spine surgery technique using intraoperative computed tomography image-guided navigation for the treatment of various lumbar spine pathologies. We present an illustrative case of a patient undergoing minimally invasive percutaneous posterior spinal fusion assisted by the O-arm system with navigation. We discuss the literature and the advantages of the technique over fluoroscopic imaging methods: lower occupational radiation exposure for operative room personnel, reduced need for postoperative imaging, and decreased revision rates. Most importantly, we demonstrate that use of intraoperative cone beam CT image-guided navigation has been reported to increase accuracy. PMID:27213152

Quantum Analysis of a Microcavity-Tuned Bloch Oscillator for Tunable Spontaneous Emission and Absorption of Terahertz Radiation

DTIC Science & Technology

2007-06-20

qz/qx) 2]1/2 is the mode dispersion relation, and ωc = qxc/ √ ε is the angular cutoff frequency. The guided mode wavelength is written as λ = λc/[(ωq...the guided modes corresponding to standing waves with respect to the X and Y axes designated by an integer pair m ,n, and propagating waves along...the angular cutoff frequency determined by the waveguide geometry. The guided mode wavelength is written as =c / q /c2−11/2, where c=2Lx is

Preliminary Design of Critical Function Monitoring System of PGSFR

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

2015-07-01

A PGSFR (Prototype Gen-IV Sodium-cooled Fast Reactor) is under development at Korea Atomic Energy Research Institute. A critical function monitoring system of the PGSFR is preliminarily studied. The functions of CFMS are to display critical plant variables related to the safety of the plant during normal and accident conditions and guide the operators corrective actions to keep the plant in a safe condition and mitigate the consequences of accidents. The minimal critical functions of the PGSFR are composed of reactivity control, reactor core cooling, reactor coolant system integrity, primary heat transfer system(PHTS) heat removal, sodium water reaction mitigation, radiation controlmore » and containment conditions. The variables and alarm legs of each critical function of the PGSFR are as follows; - Reactivity control: The variables of reactivity control function are power range neutron flux instrumentation, intermediate range neutron flux instrumentation, source range neutron flux instrumentation, and control rod bottom contacts. The alarm leg to display the reactivity controls consists of status of control drop malfunction, high post trip power and thermal reactivity addition. - Reactor core cooling: The variables are PHTS sodium level, hot pool temperature of PHTS, subassembly exit temperature, cold pool temperature of the PHTS, PHTS pump current, and PHTS pump breaker status. The alarm leg consists of high core delta temperature, low sodium level of the PHTS, high subassembly exit temperature, and low PHTS pump load. - Reactor coolant system integrity: The variables are PHTS sodium level, cover gas pressure, and safeguard vessel sodium level. The alarm leg is composed of low sodium level of PHTS, high cover gas pressure and high sodium level of the safety guard vessel. - PHTS heat removal: The variables are PHTS sodium level, hot pool temperature of PHTS, core exit temperature, cold pool temperature of the PHTS, flow rate of passive residual heat removal system, flow rate of active residual heat removal system, and temperatures of air heat exchanger temperature of residual heat removal systems. The alarm legs are composed of two legs of a 'passive residual heat removal system not cooling' and 'active residual heat removal system not cooling'. - Sodium water reaction mitigation: The variables are intermediate heat transfer system(IHTS) pressure, pressure and temperature and level of sodium dump tank, the status of rupture disk, hydrogen concentration in IHTS and direct variable of sodium-water-reaction measure. The alarm leg consists of high IHTS pressure, the status of sodium water reaction mitigation system and the indication of direct measure. - Radiation control: The variables are radiation of PHTS, radiation of IHTS, and radiation of containment purge. The alarm leg is composed of high radiation of PHTS and IHTS, and containment purge system. - Containment condition: The variables are containment pressure, containment isolation status, and sodium fire. The alarm leg consists of high containment pressure, status of containment isolation and status of sodium fire. (authors)« less

Guided wave methods and apparatus for nonlinear frequency generation

DOEpatents

Durfee, III, Charles G.; Rundquist, Andrew; Kapteyn, Henry C.; Murnane, Margaret M.

2000-01-01

Methods and apparatus are disclosed for the nonlinear generation of sum and difference frequencies of electromagnetic radiation propagating in a nonlinear material. A waveguide having a waveguide cavity contains the nonlinear material. Phase matching of the nonlinear generation is obtained by adjusting a waveguide propagation constant, the refractive index of the nonlinear material, or the waveguide mode in which the radiation propagates. Phase matching can be achieved even in isotropic nonlinear materials. A short-wavelength radiation source uses phase-matched nonlinear generation in a waveguide to produce high harmonics of a pulsed laser.

A broadband double-slot waveguide antenna

NASA Astrophysics Data System (ADS)

Kisliuk, M.; Axelrod, A.

1987-09-01

A double transverse slot broadband antenna based on the H-guide transverse-slot radiator design of Kisliuk and Axelrod (1985) is described. The double transverse slot antenna may be used in microwave and mm-wave applications (as a phased array element), in imaging systems, or as a stand-alone linearly polarized antenna. The equations for calculating the radiation efficiency and the input impedance and the experimental and theoretical curves for radiation efficiency of the double-slot antenna are presented along with diagrams of the antenna and the equivalent circuit of an individual slot in a slot array.

Intravascular Ultrasound in the Creation of Transhepatic Portosystemic Shunts Reduces Needle Passes, Radiation Dose, and Procedure Time: A Retrospective Study of a Single-Institution Experience.

PubMed

Kao, Steven D; Morshedi, Maud M; Narsinh, Kazim H; Kinney, Thomas B; Minocha, Jeet; Picel, Andrew C; Newton, Isabel; Rose, Steven C; Roberts, Anne C; Kuo, Alexander; Aryafar, Hamed

2016-08-01

To assess whether intravascular ultrasound (US) guidance impacts number of needle passes, contrast usage, radiation dose, and procedure time during creation of transjugular intrahepatic portosystemic shunts (TIPS). Intravascular US-guided creation of TIPS in 40 patients was retrospectively compared with conventional TIPS in 49 patients between February 2010 and November 2015 at a single tertiary care institution. Patient sex and age, etiology of liver disease (hepatitis C virus, alcohol abuse, nonalcoholic steatohepatitis), severity of liver disease (mean Model for End-Stage Liver Disease score), and indications for TIPS (variceal bleeding, refractory ascites, refractory hydrothorax) in conventional and intravascular US-guided cases were recorded. The two groups were well matched by sex, age, etiology of liver disease, Child-Pugh class, Model for End-Stage Liver Disease scores, and indication for TIPS (P range = .19-.94). Fewer intrahepatic needle passes were required in intravascular US-guided TIPS creation compared with conventional TIPS (2 passes vs 6 passes, P < .01). Less iodinated contrast material was used in intravascular US cases (57 mL vs 140 mL, P < .01). Radiation exposure, as measured by cumulative dose, dose area product, and fluoroscopy time, was reduced with intravascular US (174 mGy vs 981 mGy, P < .01; 3,793 μGy * m(2) vs 21,414 μGy * m(2), P < .01; 19 min vs 34 min, P < .01). Procedure time was shortened with intravascular US (86 min vs 125 min, P < .01). Intravascular US guidance resulted in fewer intrahepatic needle passes, decreased contrast medium usage, decreased radiation dosage, and shortened procedure time in TIPS creation. Copyright © 2016 SIR. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Jaesun, E-mail: jaesun@pusan.ac.kr, E-mail: jpp@pusan.ac.kr; Park, Junpil, E-mail: jaesun@pusan.ac.kr, E-mail: jpp@pusan.ac.kr; Cho, Younho, E-mail: mechcyh@pusan.ac.kr

The nuclear power plant inspection is very important for the safety issue. However due to some radiation and geometric problems, the detection of CRDM(Control Rod Drive Mechanism) can be very difficult by using conventional Ultrasonic Testing method. Also the shrink fit boundary condition can also be an obstacle for the inspection in this paper, instead of conventional Ultrasonic Testing, guided wave was used for the detection of some complicated structures. The CRDM nozzle was installed in reactor head with perfect shrink fit condition by using stainless steel. The wave amplitude distribution on the circumferential direction was calculated with various boundarymore » conditions and the experimental result shows a possibility of the defect detection on J-groove weld.« less

3D-printed guiding templates for improved osteosarcoma resection

NASA Astrophysics Data System (ADS)

Ma, Limin; Zhou, Ye; Zhu, Ye; Lin, Zefeng; Wang, Yingjun; Zhang, Yu; Xia, Hong; Mao, Chuanbin

2016-03-01

Osteosarcoma resection is challenging due to the variable location of tumors and their proximity with surrounding tissues. It also carries a high risk of postoperative complications. To overcome the challenge in precise osteosarcoma resection, computer-aided design (CAD) was used to design patient-specific guiding templates for osteosarcoma resection on the basis of the computer tomography (CT) scan and magnetic resonance imaging (MRI) of the osteosarcoma of human patients. Then 3D printing technique was used to fabricate the guiding templates. The guiding templates were used to guide the osteosarcoma surgery, leading to more precise resection of the tumorous bone and the implantation of the bone implants, less blood loss, shorter operation time and reduced radiation exposure during the operation. Follow-up studies show that the patients recovered well to reach a mean Musculoskeletal Tumor Society score of 27.125.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, T; Kim, D; Kang, S

Purpose: Abdominal compression is known to be effective but, often makes external-marker-based monitoring of breathing motion not feasible. In this study, we developed and evaluated a system that enables both abdominal compression and monitoring of residual abdominal motion simultaneously. The system can also provide visual-biofeedback capability. Methods: The system developed consists of a compression belt, an abdominal motion monitoring sensor (gas pressure sensor) and a visual biofeedback device. The compression belt was designed to be able to compress the frontal side of the abdomen. The pressure level of the belt is controlled by air volume and monitored in real timemore » using the gas pressure sensor. The system displays not only the real-time monitoring curve but also a guiding respiration model (e.g., a breath hold or shallow breathing curve) simultaneously on the head mounted display to help patients keep their breathing pattern as consistent as possible. Three healthy volunteers were enrolled in this pilot study and respiratory signals (pressure variations) were obtained both with and without effective abdominal compression to investigate the feasibility of the developed system. Two guidance patterns, breath hold and shallow breathing, were tested. Results: All volunteers showed smaller abdominal motion with compression (about 40% amplitude reduction compared to without compression). However, the system was able to monitor residual abdominal motion for all volunteers. Even under abdominal compression, in addition, it was possible to make the subjects successfully follow the guide patterns using the visual biofeedback system. Conclusion: The developed abdominal compression & respiratory guiding system was feasible for residual abdominal motion management. It is considered that the system can be used for a respiratory motion involved radiation therapy while maintaining the merit of abdominal compression. This work was supported by the Radiation Technology R&D program (No. 2013M2A2A7043498) and the Mid-career Researcher Program (2014R1A2A1A10050270) through the National Research Foundation of Korea funded by the Ministry of Science, ICT&Future Planning.« less

FLASH_TISA_Terra+Aqua_Version3C

Atmospheric Science Data Center

2018-04-04

... Cloud Particle Phase Cloud Infrared Emissivity Cloud Base Pressure Surface (Radiative) Flux TOA Flux Surface Types Albedo LW Flux Order Data:  Earthdata Search:  Order Data Guide Documents:  ...

A Method to Estimate Uncertainty in Radiometric Measurement Using the Guide to the Expression of Uncertainty in Measurement (GUM) Method; NREL (National Renewable Energy Laboratory)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habte, A.; Sengupta, M.; Reda, I.

Radiometric data with known and traceable uncertainty is essential for climate change studies to better understand cloud radiation interactions and the earth radiation budget. Further, adopting a known and traceable method of estimating uncertainty with respect to SI ensures that the uncertainty quoted for radiometric measurements can be compared based on documented methods of derivation.Therefore, statements about the overall measurement uncertainty can only be made on an individual basis, taking all relevant factors into account. This poster provides guidelines and recommended procedures for estimating the uncertainty in calibrations and measurements from radiometers. The approach follows the Guide to the Expressionmore » of Uncertainty in Measurement (GUM). derivation.Therefore, statements about the overall measurement uncertainty can only be made on an individual basis, taking all relevant factors into account. This poster provides guidelines and recommended procedures for estimating the uncertainty in calibrations and measurements from radiometers. The approach follows the Guide to the Expression of Uncertainty in Measurement (GUM).« less

Ultrasound-Guided Renal Access for Percutaneous Nephrolithotomy: A Description of Three Novel Ultrasound-Guided Needle Techniques

PubMed Central

Chu, Carissa; Masic, Selma; Usawachintachit, Manint; Hu, Weiguo; Yang, Wenzeng; Stoller, Marshall; Li, Jianxing

2016-01-01

Abstract Ultrasound-guided renal access for percutaneous nephrolithotomy (PCNL) is a safe, effective, and low-cost procedure commonly performed worldwide, but a technique underutilized by urologists in the United States. The purpose of this article is to familiarize the practicing urologist with methods for ultrasound guidance for percutaneous renal access. We discuss two alternative techniques for gaining renal access for PCNL under ultrasound guidance. We also describe a novel technique of using the puncture needle to reposition residual stone fragments to avoid additional tract dilation. With appropriate training, ultrasound-guided renal access for PCNL can lead to reduced radiation exposure, accurate renal access, and excellent stone-free success rates and clinical outcomes. PMID:26414304

Strategies to tackle the challenges of external beam radiotherapy for liver tumors.

PubMed

Lock, Michael I; Klein, Jonathan; Chung, Hans T; Herman, Joseph M; Kim, Edward Y; Small, William; Mayr, Nina A; Lo, Simon S

2017-05-18

Primary and metastatic liver cancer is an increasingly common and difficult to control disease entity. Radiation offers a non-invasive treatment alternative for these patients who often have few options and a poor prognosis. However, the anatomy and aggressiveness of liver cancer poses significant challenges such as accurate localization at simulation and treatment, management of motion and appropriate selection of dose regimen. This article aims to review the options available and provide information for the practical implementation and/or improvement of liver cancer radiation programs within the context of stereotactic body radiotherapy and image-guided radiotherapy guidelines. Specific patient inclusion and exclusion criteria are presented given the significant toxicity found in certain sub-populations treated with radiation. Indeed, certain sub-populations, such as those with tumor thrombosis or those with larger lesions treated with transarterial chemoembolization, have been shown to have significant improvements in outcome with the addition of radiation and merit special consideration. Implementing a liver radiation program requires three primary challenges to be addressed: (1) immobilization and motion management; (2) localization; and (3) dose regimen and constraint selection. Strategies to deal with motion include simple internal target volume (ITV) expansions, non-gated ITV reduction strategies, breath hold methods, and surrogate marker methods to enable gating or tracking. Localization of the tumor and organs-at-risk are addressed using contrast infusion techniques to take advantage of different normal liver and cancer vascular anatomy, imaging modalities, and margin management. Finally, a dose response has been demonstrated and dose regimens appear to be converging. A more uniform approach to treatment in terms of technique, dose selection and patient selection will allow us to study liver radiation in larger and, hopefully, multicenter randomized studies.

Anticancer redox activity of gallium nanoparticles accompanied with low dose of gamma radiation in female mice.

PubMed

Kandil, Eman I; El-Sonbaty, Sawsan M; Moawed, Fatma Sm; Khedr, Ola Ms

2018-03-01

Guided treatments with nanoparticles and radiotherapy are a new approach in cancer therapy. This study evaluated the beneficial antitumor effects of γ-radiation together with gallium nanoparticles against solid Ehrlich carcinoma in female mice. Gallium nanoparticles were biologically synthesized using Lactobacillus helveticus cells. Transmission electron microscopy showed gallium nanoparticles with size range of 8-20 nm. In vitro study of gallium nanoparticles on MCF-7 revealed IC 50 of 8.0 μg. Gallium nanoparticles (0.1 mg/kg body weight) were injected intraperitoneally daily on the seventh day of Ehrlich carcinoma cells inoculation. Whole-body γ-radiation was carried out at a single dose of 0.25 Gy on eighth day after tumor inoculation. Biochemical analysis showed that solid Ehrlich carcinoma induced a significant increase in alanine aminotransferase activity and creatinine level in serum, calcium, and iron concentrations in liver tissue compared to normal control. Treatment of Ehrlich carcinoma-bearing mice with gallium nanoparticles and/or low dose of γ-radiation exposure significantly reduced tumor volume, decreased alanine aminotransferase and creatinine levels in serum, increased lipid peroxidation, and decreased glutathione content as well as calcium and iron concentrations in liver and tumor tissues with intense DNA fragmentation accompanied compared to untreated tumor cells. Moreover, mitochondria in the treated groups displayed a significant increase in Na+/K+-ATPase, complexes II and III with significant reduction in CYP450 gene expression, which may indicate a synergistic effect of gallium nanoparticles and/or low dose of γ-radiation combination against Ehrlich carcinoma injury, and this results were well appreciated with the histopathological findings in the tumor tissue. We conclude that combined treatment of gallium nanoparticles and low dose of gamma-radiation resulted in suppressive induction of cytotoxic effects on cancer cells.

Strategies to tackle the challenges of external beam radiotherapy for liver tumors

PubMed Central

Lock, Michael I; Klein, Jonathan; Chung, Hans T; Herman, Joseph M; Kim, Edward Y; Small, William; Mayr, Nina A; Lo, Simon S

2017-01-01

Primary and metastatic liver cancer is an increasingly common and difficult to control disease entity. Radiation offers a non-invasive treatment alternative for these patients who often have few options and a poor prognosis. However, the anatomy and aggressiveness of liver cancer poses significant challenges such as accurate localization at simulation and treatment, management of motion and appropriate selection of dose regimen. This article aims to review the options available and provide information for the practical implementation and/or improvement of liver cancer radiation programs within the context of stereotactic body radiotherapy and image-guided radiotherapy guidelines. Specific patient inclusion and exclusion criteria are presented given the significant toxicity found in certain sub-populations treated with radiation. Indeed, certain sub-populations, such as those with tumor thrombosis or those with larger lesions treated with transarterial chemoembolization, have been shown to have significant improvements in outcome with the addition of radiation and merit special consideration. Implementing a liver radiation program requires three primary challenges to be addressed: (1) immobilization and motion management; (2) localization; and (3) dose regimen and constraint selection. Strategies to deal with motion include simple internal target volume (ITV) expansions, non-gated ITV reduction strategies, breath hold methods, and surrogate marker methods to enable gating or tracking. Localization of the tumor and organs-at-risk are addressed using contrast infusion techniques to take advantage of different normal liver and cancer vascular anatomy, imaging modalities, and margin management. Finally, a dose response has been demonstrated and dose regimens appear to be converging. A more uniform approach to treatment in terms of technique, dose selection and patient selection will allow us to study liver radiation in larger and, hopefully, multicenter randomized studies. PMID:28588749

Image Guided Radiation Therapy (IGRT) Practice Patterns and IGRT's Impact on Workflow and Treatment Planning: Results From a National Survey of American Society for Radiation Oncology Members

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nabavizadeh, Nima, E-mail: nabaviza@ohsu.edu; Elliott, David A.; Chen, Yiyi

Purpose: To survey image guided radiation therapy (IGRT) practice patterns, as well as IGRT's impact on clinical workflow and planning treatment volumes (PTVs). Methods and Materials: A sample of 5979 treatment site–specific surveys was e-mailed to the membership of the American Society for Radiation Oncology (ASTRO), with questions pertaining to IGRT modality/frequency, PTV expansions, method of image verification, and perceived utility/value of IGRT. On-line image verification was defined as images obtained and reviewed by the physician before treatment. Off-line image verification was defined as images obtained before treatment and then reviewed by the physician before the next treatment. Results: Of 601 evaluablemore » responses, 95% reported IGRT capabilities other than portal imaging. The majority (92%) used volumetric imaging (cone-beam CT [CBCT] or megavoltage CT), with volumetric imaging being the most commonly used modality for all sites except breast. The majority of respondents obtained daily CBCTs for head and neck intensity modulated radiation therapy (IMRT), lung 3-dimensional conformal radiation therapy or IMRT, anus or pelvis IMRT, prostate IMRT, and prostatic fossa IMRT. For all sites, on-line image verification was most frequently performed during the first few fractions only. No association was seen between IGRT frequency or CBCT utilization and clinical treatment volume to PTV expansions. Of the 208 academic radiation oncologists who reported working with residents, only 41% reported trainee involvement in IGRT verification processes. Conclusion: Consensus guidelines, further evidence-based approaches for PTV margin selection, and greater resident involvement are needed for standardized use of IGRT practices.« less

Image Guided Radiation Therapy (IGRT) Practice Patterns and IGRT's Impact on Workflow and Treatment Planning: Results From a National Survey of American Society for Radiation Oncology Members.

PubMed

Nabavizadeh, Nima; Elliott, David A; Chen, Yiyi; Kusano, Aaron S; Mitin, Timur; Thomas, Charles R; Holland, John M

2016-03-15

To survey image guided radiation therapy (IGRT) practice patterns, as well as IGRT's impact on clinical workflow and planning treatment volumes (PTVs). A sample of 5979 treatment site-specific surveys was e-mailed to the membership of the American Society for Radiation Oncology (ASTRO), with questions pertaining to IGRT modality/frequency, PTV expansions, method of image verification, and perceived utility/value of IGRT. On-line image verification was defined as images obtained and reviewed by the physician before treatment. Off-line image verification was defined as images obtained before treatment and then reviewed by the physician before the next treatment. Of 601 evaluable responses, 95% reported IGRT capabilities other than portal imaging. The majority (92%) used volumetric imaging (cone-beam CT [CBCT] or megavoltage CT), with volumetric imaging being the most commonly used modality for all sites except breast. The majority of respondents obtained daily CBCTs for head and neck intensity modulated radiation therapy (IMRT), lung 3-dimensional conformal radiation therapy or IMRT, anus or pelvis IMRT, prostate IMRT, and prostatic fossa IMRT. For all sites, on-line image verification was most frequently performed during the first few fractions only. No association was seen between IGRT frequency or CBCT utilization and clinical treatment volume to PTV expansions. Of the 208 academic radiation oncologists who reported working with residents, only 41% reported trainee involvement in IGRT verification processes. Consensus guidelines, further evidence-based approaches for PTV margin selection, and greater resident involvement are needed for standardized use of IGRT practices. Copyright © 2016 Elsevier Inc. All rights reserved.

Approach for chronic total occlusion with intravascular ultrasound-guided reverse controlled antegrade and retrograde tracking technique: single center experience.

PubMed

Dai, Jian; Katoh, Osamu; Kyo, Eisho; Tsuji, Takafumi; Watanabe, Satoshi; Ohya, Hidefumi

2013-10-01

Controlled antegrade and retrograde subintimal tracking (CART) or reverse CART techniques is the final step for percutaneous revascularization of coronary chronic total occlusion (CTO), but it still represents technical challenges and risk in interventional procedures. Our purpose was to utilize intravascular ultrasound (IVUS)-guided reverse CART approach for percutaneous revascularization of CTO in our heart center, focusing on its safety, efficacy, and latest technical developments. From November 2006 to November 2012, 49 patients with CTO failed to antegrade and/or retrograde percutaneous revascularization of CTO from true lumen to true lumen were enrolled in and underwent IVUS guided reverse CART approach. The mean J-CTO score of cases was 2.5. IVUS guidance was successfully implemented in 95.9%; IVUS identified that 61.7% of retrograde wires were located at intimal space, and 59.5% of antegrade wires were located at subintimal space. A Corsair channel dilator was used in 77.6% of cases. The success rates of technique and procedure were 95.9% and 93.9%, respectively; the technical minor complications were observed in 10.2% of cases, without significant clinic outcomes; 2.0% of cases occurred with a major adverse cardiac event of non-ST-elevation myocardial infarction; and no case occurred with target vessel revascularization or death. The mean length of stent implanted in a single CTO vessel was 51.3 mm. No patient appeared with radiation dermatitis and contrast-induced rise of creatinine. IVUS guided reverse CART approach is effective and safe for percutaneous revascularization of complex CTO, with a high success and a low complication rate. It is feasible to develop this approach for percutaneous revascularization of complex CTO. However, suitable case selection and lately device handling by experienced operators are the crucial points of success. © 2013, Wiley Periodicals, Inc.

WE-FG-BRA-06: Systematic Study of Target Localization for Bioluminescence Tomography Guided Radiation Therapy for Preclinical Research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, B; Reyes, J; Wong, J

Purpose: To overcome the limitation of CT/CBCT in guiding radiation for soft tissue targets, we developed a bioluminescence tomography(BLT) system for preclinical radiation research. We systematically assessed the system performance in target localization and the ability of resolving two sources in simulations, phantom and in vivo environments. Methods: Multispectral images acquired in single projection were used for the BLT reconstruction. Simulation studies were conducted for single spherical source radius from 0.5 to 3 mm at depth of 3 to 12 mm. The same configuration was also applied for the double sources simulation with source separations varying from 3 to 9more » mm. Experiments were performed in a standalone BLT/CBCT system. Two sources with 3 and 4.7 mm separations placed inside a tissue-mimicking phantom were chosen as the test cases. Live mice implanted with single source at 6 and 9 mm depth, 2 sources with 3 and 5 mm separation at depth of 5 mm or 3 sources in the abdomen were also used to illustrate the in vivo localization capability of the BLT system. Results: Simulation and phantom results illustrate that our BLT can provide 3D source localization with approximately 1 mm accuracy. The in vivo results are encouraging that 1 and 1.7 mm accuracy can be attained for the single source case at 6 and 9 mm depth, respectively. For the 2 sources study, both sources can be distinguished at 3 and 5 mm separations at approximately 1 mm accuracy using 3D BLT but not 2D bioluminescence image. Conclusion: Our BLT/CBCT system can be potentially applied to localize and resolve targets at a wide range of target sizes, depths and separations. The information provided in this study can be instructive to devise margins for BLT-guided irradiation and suggests that the BLT could guide radiation for multiple targets, such as metastasis. Drs. John W. Wong and Iulian I. Iordachita receive royalty payment from a licensing agreement between Xstrahl Ltd and Johns Hopkins University.« less

SU-C-BRA-01: Interactive Auto-Segmentation for Bowel in Online Adaptive MRI-Guided Radiation Therapy by Using a Multi-Region Labeling Algorithm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lu, Y; Chen, I; Kashani, R

Purpose: In MRI-guided online adaptive radiation therapy, re-contouring of bowel is time-consuming and can impact the overall time of patients on table. The study aims to auto-segment bowel on volumetric MR images by using an interactive multi-region labeling algorithm. Methods: 5 Patients with locally advanced pancreatic cancer underwent fractionated radiotherapy (18–25 fractions each, total 118 fractions) on an MRI-guided radiation therapy system with a 0.35 Tesla magnet and three Co-60 sources. At each fraction, a volumetric MR image of the patient was acquired when the patient was in the treatment position. An interactive two-dimensional multi-region labeling technique based on graphmore » cut solver was applied on several typical MRI images to segment the large bowel and small bowel, followed by a shape based contour interpolation for generating entire bowel contours along all image slices. The resulted contours were compared with the physician’s manual contouring by using metrics of Dice coefficient and Hausdorff distance. Results: Image data sets from the first 5 fractions of each patient were selected (total of 25 image data sets) for the segmentation test. The algorithm segmented the large and small bowel effectively and efficiently. All bowel segments were successfully identified, auto-contoured and matched with manual contours. The time cost by the algorithm for each image slice was within 30 seconds. For large bowel, the calculated Dice coefficients and Hausdorff distances (mean±std) were 0.77±0.07 and 13.13±5.01mm, respectively; for small bowel, the corresponding metrics were 0.73±0.08and 14.15±4.72mm, respectively. Conclusion: The preliminary results demonstrated the potential of the proposed algorithm in auto-segmenting large and small bowel on low field MRI images in MRI-guided adaptive radiation therapy. Further work will be focused on improving its segmentation accuracy and lessening human interaction.« less

High-flow vascular malformation treatment using ultrasound-guided laser combined with polidocanol sclerotherapy.

PubMed

Zhang, Yan; Zhou, Ping; Li, Lan; Li, Jia-le

2015-07-01

The current treatment for vascular malformations includes surgery, sclerotherapy, and embolization. However, each method has its limitations, such as recurrence, complications, scarring, and radiation exposure. Therefore, identifying an effective, minimally invasive treatment that reduces lesion recurrence is particularly important. We describe in detail a patient who received treatment with ultrasound-guided laser interruption of feeding vessels combined with polidocanol sclerotherapy after the recurrence of forearm high-flow vascular malformation.

Efficacy, safety and outcome of frameless image-guided robotic radiosurgery for brain metastases after whole brain radiotherapy.

PubMed

Lohkamp, Laura-Nanna; Vajkoczy, Peter; Budach, Volker; Kufeld, Markus

2018-05-01

Estimating efficacy, safety and outcome of frameless image-guided robotic radiosurgery for the treatment of recurrent brain metastases after whole brain radiotherapy (WBRT). We performed a retrospective single-center analysis including patients with recurrent brain metastases after WBRT, who have been treated with single session radiosurgery, using the CyberKnife® Radiosurgery System (CKRS) (Accuray Inc., CA) between 2011 and 2016. The primary end point was local tumor control, whereas secondary end points were distant tumor control, treatment-related toxicity and overall survival. 36 patients with 140 recurrent brain metastases underwent 46 single session CKRS treatments. Twenty one patients had multiple brain metastases (58%). The mean interval between WBRT and CKRS accounted for 2 years (range 0.2-7 years). The median number of treated metastases per treatment session was five (range 1-12) with a tumor volume of 1.26 ccm (mean) and a median tumor dose of 18 Gy prescribed to the 70% isodose line. Two patients experienced local tumor recurrence within the 1st year after treatment and 13 patients (36%) developed novel brain metastases. Nine of these patients underwent additional one to three CKRS treatments. Eight patients (22.2%) showed treatment-related radiation reactions on MRI, three with clinical symptoms. Median overall survival was 19 months after CKRS. The actuarial 1-year local control rate was 94.2%. CKRS has proven to be locally effective and safe due to high local tumor control rates and low toxicity. Thus CKRS offers a reliable salvage treatment option for recurrent brain metastases after WBRT.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rangaraj, D; Chan, K; Boddu, S

Lean thinking has revolutionized the manufacturing industry. Toyota has pioneered and leveraged this aspect of Lean thinking. Application of Lean thinking and Lean Six Sigma techniques into Healthcare and in particular in Radiation Oncology has its merits and challenges. To improve quality, safety and patient satisfaction with available resources or reducing cost in terms of time, staff and resources is demands of today's healthcare. Radiation oncology treatment involves many processes and steps, identifying and removing the non-value added steps in a process can significantly improve the efficiency. Real projects undertaken in radiation oncology department in cutting down the procedure timemore » for MRI guided brachytherapy to 40% less using lean thinking will be narrated. Simple Lean tools and techniques such as Gemba walk, visual control, daily huddles, standard work, value stream mapping, error-proofing, etc. can be applied with existing resources and how that improved the operation in a Radiation Oncology department's two year experience will be discussed. Lean thinking focuses on identifying and solving the root-cause of a problem by asking “Why” and not “Who” and this requires a culture change of no blame. Role of leadership in building lean culture, employee empowerment and trains and develops lean thinkers will be presented. Why Lean initiatives fail and how to implement lean successfully in your clinic will be discussed. Learning Objectives: Concepts of lean management or lean thinking. Lean tools and techniques applied in Radiation Oncology. Implement no blame culture and focus on system and processes. Leadership role in implementing lean culture. Challenges for Lean thinking in healthcare.« less

Spatiotemporal dynamics of brain activity during the transition from visually guided to memory-guided force control

PubMed Central

Poon, Cynthia; Chin-Cottongim, Lisa G.; Coombes, Stephen A.; Corcos, Daniel M.

2012-01-01

It is well established that the prefrontal cortex is involved during memory-guided tasks whereas visually guided tasks are controlled in part by a frontal-parietal network. However, the nature of the transition from visually guided to memory-guided force control is not as well established. As such, this study examines the spatiotemporal pattern of brain activity that occurs during the transition from visually guided to memory-guided force control. We measured 128-channel scalp electroencephalography (EEG) in healthy individuals while they performed a grip force task. After visual feedback was removed, the first significant change in event-related activity occurred in the left central region by 300 ms, followed by changes in prefrontal cortex by 400 ms. Low-resolution electromagnetic tomography (LORETA) was used to localize the strongest activity to the left ventral premotor cortex and ventral prefrontal cortex. A second experiment altered visual feedback gain but did not require memory. In contrast to memory-guided force control, altering visual feedback gain did not lead to early changes in the left central and midline prefrontal regions. Decreasing the spatial amplitude of visual feedback did lead to changes in the midline central region by 300 ms, followed by changes in occipital activity by 400 ms. The findings show that subjects rely on sensorimotor memory processes involving left ventral premotor cortex and ventral prefrontal cortex after the immediate transition from visually guided to memory-guided force control. PMID:22696535

Theater Land Attack Cruise Missile Defense: Guarding the Back Door

DTIC Science & Technology

1999-06-01

employ radio command, laser, anti- radiation homing, or electro-optical guidance systems. TASMs will benefit from the same technological developments...mile-range Al-Husayn missile within range of all major Israeli cities, and its nuclear facilities in the Negev desert. The existence of these sites...solutions (“engage on remote”), or simply launch missiles without radiating , and allow the AFCR to guide the missiles to the target

Guide to U.S. Atmospheric Nuclear Weapon Effects Data

DTIC Science & Technology

1993-12-01

biological warfare agents, and radiation dosimeters . XRD- 163 identifies the test location of each 4-6 biological sample. Reports containing the results...along with position of the animals at the time of the detonation. Vycor Glass Gamma Ray Dosimeters XRD-176 A rugged new dosimeter capable of measuring...gamma doses on animals exposed to high levels of radiation was employed during Able. Dosimeter readings, locations, and animal condition are reported

Intraarticular Sacroiliac Joint Injection Under Computed Tomography Fluoroscopic Guidance: A Technical Note to Reduce Procedural Time and Radiation Dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paik, Nam Chull, E-mail: pncspine@gmail.com

2016-07-15

PurposeA technique for computed tomography fluoroscopy (CTF)-guided intraarticular (IA) sacroiliac joint (SIJ) injection was devised to limit procedural time and radiation dose.MethodsOur Institutional Review Board approved this retrospective analysis and waived the requirement for informed consent. Overall, 36 consecutive diagnostic or therapeutic IA SIJ injections (unilateral, 20; bilateral, 16) performed in 34 patients (female, 18; male, 16) with a mean age of 45.5 years (range 20–76 years) under CTF guidance were analyzed, assessing technical success (i.e., IA contrast spread), procedural time, and radiation dose.ResultsAll injections were successful from a technical perspective and were free of serious complications. Respective median proceduralmore » times and effective doses of SIJ injection were as follows: unilateral, 5.28 min (range 3.58–8.00 min) and 0.11 millisievert (mSv; range 0.07–0.24 mSv); and bilateral, 6.72 min (range 4.17–21.17 min) and 0.11 mSv (range 0.09–0.51 mSv).ConclusionsGiven the high rate of technical success achieved in limited time duration and with little radiation exposure, CTF-guided IA SIJ injection is a practical and low-risk procedure.« less

Occupational exposures during abdominal fluoroscopically guided interventional procedures for different patient sizes - A Monte Carlo approach.

PubMed

Santos, William S; Belinato, Walmir; Perini, Ana P; Caldas, Linda V E; Galeano, Diego C; Santos, Carla J; Neves, Lucio P

2018-01-01

In this study we evaluated the occupational exposures during an abdominal fluoroscopically guided interventional radiology procedure. We investigated the relation between the Body Mass Index (BMI), of the patient, and the conversion coefficient values (CC) for a set of dosimetric quantities, used to assess the exposure risks of medical radiation workers. The study was performed using a set of male and female virtual anthropomorphic phantoms, of different body weights and sizes. In addition to these phantoms, a female and a male phantom, named FASH3 and MASH3 (reference virtual anthropomorphic phantoms), were also used to represent the medical radiation workers. The CC values, obtained as a function of the dose area product, were calculated for 87 exposure scenarios. In each exposure scenario, three phantoms, implemented in the MCNPX 2.7.0 code, were simultaneously used. These phantoms were utilized to represent a patient and medical radiation workers. The results showed that increasing the BMI of the patient, adjusted for each patient protocol, the CC values for medical radiation workers decrease. It is important to note that these results were obtained with fixed exposure parameters. Copyright © 2017 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

KENNEDY SPACE CENTER, FLA. - Workers at Hangar A&E, Cape Canaveral Air Force Station, help guide the upper canister toward the Space Infrared Telescope Facility (SIRTF) at left. After encapsulation is complete, the spacecraft will be transported to Launch Complex 17-B for mating with its launch vehicle, the Delta II rocket. SIRTF consists of three cryogenically cooled science instruments and an 0.85-meter telescope, and is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

NASA Image and Video Library

2003-08-07

KENNEDY SPACE CENTER, FLA. - Workers at Hangar A&E, Cape Canaveral Air Force Station, help guide the upper canister toward the Space Infrared Telescope Facility (SIRTF) at left. After encapsulation is complete, the spacecraft will be transported to Launch Complex 17-B for mating with its launch vehicle, the Delta II rocket. SIRTF consists of three cryogenically cooled science instruments and an 0.85-meter telescope, and is one of NASA's largest infrared telescopes to be launched. SIRTF will obtain images and spectra by detecting the infrared energy, or heat, radiated by objects in space. Most of this infrared radiation is blocked by the Earth's atmosphere and cannot be observed from the ground.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsui, Yusuke, E-mail: wckyh140@yahoo.co.jp; Hiraki, Takao, E-mail: takaoh@tc4.so-net.ne.jp; Gobara, Hideo, E-mail: gobara@cc.okayama-u.ac.jp

IntroductionComputed tomography (CT) fluoroscopy-guided renal cryoablation and lung radiofrequency ablation (RFA) have received increasing attention as promising cancer therapies. Although radiation exposure of interventional radiologists during these procedures is an important concern, data on operator exposure are lacking.Materials and MethodsRadiation dose to interventional radiologists during CT fluoroscopy-guided renal cryoablation (n = 20) and lung RFA (n = 20) was measured prospectively in a clinical setting. Effective dose to the operator was calculated from the 1-cm dose equivalent measured on the neck outside the lead apron, and on the left chest inside the lead apron, using electronic dosimeters. Equivalent dose to the operator’s finger skinmore » was measured using thermoluminescent dosimeter rings.ResultsThe mean (median) effective dose to the operator per procedure was 6.05 (4.52) μSv during renal cryoablation and 0.74 (0.55) μSv during lung RFA. The mean (median) equivalent dose to the operator’s finger skin per procedure was 2.1 (2.1) mSv during renal cryoablation, and 0.3 (0.3) mSv during lung RFA.ConclusionRadiation dose to interventional radiologists during renal cryoablation and lung RFA were at an acceptable level, and in line with recommended dose limits for occupational radiation exposure.« less

System Integration and In Vivo Testing of a Robot for Ultrasound Guidance and Monitoring During Radiotherapy.

PubMed

Sen, Hasan Tutkun; Bell, Muyinatu A Lediju; Zhang, Yin; Ding, Kai; Boctor, Emad; Wong, John; Iordachita, Iulian; Kazanzides, Peter

2017-07-01

We are developing a cooperatively controlled robot system for image-guided radiation therapy (IGRT) in which a clinician and robot share control of a 3-D ultrasound (US) probe. IGRT involves two main steps: 1) planning/simulation and 2) treatment delivery. The goals of the system are to provide guidance for patient setup and real-time target monitoring during fractionated radiotherapy of soft tissue targets, especially in the upper abdomen. To compensate for soft tissue deformations created by the probe, we present a novel workflow where the robot holds the US probe on the patient during acquisition of the planning computerized tomography image, thereby ensuring that planning is performed on the deformed tissue. The robot system introduces constraints (virtual fixtures) to help to produce consistent soft tissue deformation between simulation and treatment days, based on the robot position, contact force, and reference US image recorded during simulation. This paper presents the system integration and the proposed clinical workflow, validated by an in vivo canine study. The results show that the virtual fixtures enable the clinician to deviate from the recorded position to better reproduce the reference US image, which correlates with more consistent soft tissue deformation and the possibility for more accurate patient setup and radiation delivery.

Dosimetric evaluation of planning target volume margin reduction for prostate cancer via image-guided intensity-modulated radiation therapy

NASA Astrophysics Data System (ADS)

Hwang, Taejin; Kang, Sei-Kwon; Cheong, Kwang-Ho; Park, Soah; Yoon, Jai-Woong; Han, Taejin; Kim, Haeyoung; Lee, Meyeon; Kim, Kyoung-Joo; Bae, Hoonsik; Suh, Tae-Suk

2015-07-01

The aim of this study was to quantitatively estimate the dosimetric benefits of the image-guided radiation therapy (IGRT) system for the prostate intensity-modulated radiation therapy (IMRT) delivery. The cases of eleven patients who underwent IMRT for prostate cancer without a prostatectomy at our institution between October 2012 and April 2014 were retrospectively analyzed. For every patient, clinical target volume (CTV) to planning target volume (PTV) margins were uniformly used: 3 mm, 5 mm, 7 mm, 10 mm, 12 mm, and 15 mm. For each margin size, the IMRT plans were independently optimized by one medical physicist using Pinnalce3 (ver. 8.0.d, Philips Medical System, Madison, WI) in order to maintain the plan quality. The maximum geometrical margin (MGM) for every CT image set, defined as the smallest margin encompassing the rectum at least at one slice, was between 13 mm and 26 mm. The percentage rectum overlapping PTV (%V ROV ), the rectal normal tissue complication probability (NTCP) and the mean rectal dose (%RD mean ) increased in proportion to the increase of PTV margin. However the bladder NTCP remained around zero to some extent regardless of the increase of PTV margin while the percentage bladder overlapping PTV (%V BOV ) and the mean bladder dose (%BD mean ) increased in proportion to the increase of PTV margin. Without relatively large rectum or small bladder, the increase observed for rectal NTCP, %RDmean and %BD mean per 1-mm PTV margin size were 1.84%, 2.44% and 2.90%, respectively. Unlike the behavior of the rectum or the bladder, the maximum dose on each femoral head had little effect on PTV margin. This quantitative study of the PTV margin reduction supported that IG-IMRT has enhanced the clinical effects over prostate cancer with the reduction of normal organ complications under the similar level of PTV control.

Prospective Study Delivering Simultaneous Integrated High-dose Tumor Boost (≤70 Gy) With Image Guided Adaptive Radiation Therapy for Radical Treatment of Localized Muscle-Invasive Bladder Cancer

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hafeez, Shaista, E-mail: Shaista.Hafeez@icr.ac.uk; The Royal Marsden National Health Service Foundation Trust, London; Warren-Oseni, Karole

Purpose: Image guided adaptive radiation therapy offers individualized solutions to improve target coverage and reduce normal tissue irradiation, allowing the opportunity to increase the radiation tumor dose and spare normal bladder tissue. Methods and Materials: A library of 3 intensity modulated radiation therapy plans were created (small, medium, and large) from planning computed tomography (CT) scans performed at 30 and 60 minutes; treating the whole bladder to 52 Gy and the tumor to 70 Gy in 32 fractions. A “plan of the day” approach was used for treatment delivery. A post-treatment cone beam CT (CBCT) scan was acquired weekly to assess intrafraction fillingmore » and coverage. Results: A total of 18 patients completed treatment to 70 Gy. The plan and treatment for 1 patient was to 68 Gy. Also, 1 patient's plan was to 70 Gy but the patient was treated to a total dose of 65.6 Gy because dose-limiting toxicity occurred before dose escalation. A total of 734 CBCT scans were evaluated. Small, medium, and large plans were used in 36%, 48%, and 16% of cases, respectively. The mean ± standard deviation rate of intrafraction filling at the start of treatment (ie, week 1) was 4.0 ± 4.8 mL/min (range 0.1-19.4) and at end of radiation therapy (ie, week 5 or 6) was 1.1 ± 1.6 mL/min (range 0.01-7.5; P=.002). The mean D{sub 98} (dose received by 98% volume) of the tumor boost and bladder as assessed on the post-treatment CBCT scan was 97.07% ± 2.10% (range 89.0%-104%) and 99.97% ± 2.62% (range 96.4%-112.0%). At a median follow-up period of 19 months (range 4-33), no muscle-invasive recurrences had developed. Two patients experienced late toxicity (both grade 3 cystitis) at 5.3 months (now resolved) and 18 months after radiation therapy. Conclusions: Image guided adaptive radiation therapy using intensity modulated radiation therapy to deliver a simultaneous integrated tumor boost to 70 Gy is feasible, with acceptable toxicity, and will be evaluated in a randomized trial.« less

Mongoose ASIC microcontroller programming guide

NASA Astrophysics Data System (ADS)

Smith, Brian S.

1993-09-01

The 'Mongoose' ASIC microcontroller is a radiation-hard implementation of the R3000 microprocessor. This document describes the internals of the microcontroller in a level of detail necessary for someone implementing a software design.

Mongoose ASIC microcontroller programming guide

NASA Technical Reports Server (NTRS)

Smith, Brian S.

1993-01-01

The 'Mongoose' ASIC microcontroller is a radiation-hard implementation of the R3000 microprocessor. This document describes the internals of the microcontroller in a level of detail necessary for someone implementing a software design.

Theory of topological insulator waveguides: polarization control and the enhancement of the magneto-electric effect

PubMed Central

Crosse, J. A.

2017-01-01

Topological insulators subject to a time-reversal-symmetry-breaking perturbation are predicted to display a magneto-electric effect that causes the electric and magnetic induction fields to mix at the material’s surface. This effect induces polarization rotations of between ≈1–10 mrad per interface in an incident plane-polarized electromagnetic wave normal to a multilayered structure. Here we show, theoretically and numerically, that by using a waveguide geometry with a topological insulator guide layer and magneto-dielectric cladding it is possible to achieve rotations of ≈100 mrad and generate an elliptical polarization with only a three-layered structure. This geometry is beneficial, not only as a way to enhance the magneto-electric effect, rendering it easier to observe, but also as a method for controlling the polarization of electromagnetic radiation. PMID:28220875

Cancer cervix: Establishing an evidence-based strategy, an experience of a tertiary care centre in India.

PubMed

Shrivastava, Shyam Kishore; Lewis, Shirley; Sastri, Supriya Chopra; Lavanya, G; Mahantshetty, Umesh; Engineer, Reena

2018-01-12

Carcinoma cervix is a common cancer among Indian women. Evidence based management is essential for best practice in treatment of carcinoma cervix for its effective control. The current imaging system like CT, MRI and PET CT scans have contributed in identifying the patients for optimal treatment and delivering treatment accurately. For stages IB2 to IV, concurrent chemoradiation is advocated with improvement in overall survival proven with randomized trials. Brachytherapy is an integral part in the radiation treatment. Imaged-guided brachytherapy using MRI is desirable, however less expensive imaging modalities such as CT and ultrasonography has been evaluated. In special situation such as for HIV positive patients and patients with neuroendocrine tumors have role of radiotherapy. For further improvement in control of cancer, it is required to integrate basic research to answer clinically relevant questions. Copyright © 2018 Elsevier Inc. All rights reserved.

Trimodality therapy in bladder cancer: Who, what and when?

PubMed Central

Premo, Christopher; Apolo, Andrea B.; Agarwal, Piyush K.

2015-01-01

Summary Radical cystectomy is a standard treatment for non-metastatic, muscle-invasive bladder cancer. Treatment with trimodality therapy consisting of maximal transurethral resection of the bladder tumor (TURBT) followed by concurrent chemotherapy and radiation has emerged as a method to preserve the native bladder in highly motivated patients. A number of factors can impact the likelihood of long term bladder preservation after trimodality therapy, and therefore should be taken into account when selecting patients. New radiation techniques such as intensity modulated radiation therapy and image guided radiation therapy may decrease the toxicity of radiotherapy in this setting, but remain an area of active study. Novel chemotherapy regimens may improve response rates and minimize toxicity. PMID:25882559

US screening of international travelers for radioactive contamination after the Japanese nuclear plant disaster in March 2011.

PubMed

Wilson, Todd; Chang, Arthur; Berro, Andre; Still, Aaron; Brown, Clive; Demma, Andrew; Nemhauser, Jeffrey; Martin, Colleen; Salame-Alfie, Adela; Fisher-Tyler, Frieda; Smith, Lee; Grady-Erickson, Onalee; Alvarado-Ramy, Francisco; Brunette, Gary; Ansari, Armin; McAdam, David; Marano, Nina

2012-10-01

On March 11, 2011, a magnitude 9.0 earthquake and subsequent tsunami damaged nuclear reactors at the Fukushima Daiichi complex in Japan, resulting in radionuclide release. In response, US officials augmented existing radiological screening at its ports of entry (POEs) to detect and decontaminate travelers contaminated with radioactive materials. During March 12 to 16, radiation screening protocols detected 3 travelers from Japan with external radioactive material contamination at 2 air POEs. Beginning March 23, federal officials collaborated with state and local public health and radiation control authorities to enhance screening and decontamination protocols at POEs. Approximately 543 000 (99%) travelers arriving directly from Japan at 25 US airports were screened for radiation contamination from March 17 to April 30, and no traveler was detected with contamination sufficient to require a large-scale public health response. The response highlighted synergistic collaboration across government levels and leveraged screening methods already in place at POEs, leading to rapid protocol implementation. Policy development, planning, training, and exercising response protocols and the establishment of federal authority to compel decontamination of travelers are needed for future radiological responses. Comparison of resource-intensive screening costs with the public health yield should guide policy decisions, given the historically low frequency of contaminated travelers arriving during radiological disasters.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tinkle, Christopher L.; Weinberg, Vivian; Chen, Lee-May

Purpose: Evaluate the efficacy and toxicity of image guided brachytherapy using inverse planning simulated annealing (IPSA) high-dose-rate brachytherapy (HDRB) boost for locoregionally advanced cervical cancer. Methods and Materials: From December 2003 through September 2009, 111 patients with primary cervical cancer were treated definitively with IPSA-planned HDRB boost (28 Gy in 4 fractions) after external radiation at our institution. We performed a retrospective review of our experience using image guided brachytherapy. Of the patients, 70% had a tumor size >4 cm, 38% had regional nodal disease, and 15% had clinically evident distant metastasis, including nonregional nodal disease, at the time of diagnosis. Surgicalmore » staging involving pelvic lymph node dissection was performed in 15% of patients, and 93% received concurrent cisplatin-based chemotherapy. Toxicities are reported according to the Common Terminology Criteria for Adverse Events version 4.0 guidelines. Results: With a median follow-up time of 42 months (range, 3-84 months), no acute or late toxicities of grade 4 or higher were observed, and grade 3 toxicities (both acute and late) developed in 8 patients (1 constitutional, 1 hematologic, 2 genitourinary, 4 gastrointestinal). The 4-year Kaplan-Meier estimate of late grade 3 toxicity was 8%. Local recurrence developed in 5 patients (4 to 9 months after HDRB), regional recurrence in 3 (6, 16, and 72 months after HDRB), and locoregional recurrence in 1 (4 months after HDR boost). The 4-year estimates of local, locoregional, and distant control of disease were 94.0%, 91.9%, and 69.1%, respectively. The overall and disease-free survival rates at 4 years were 64.3% (95% confidence interval [CI] of 54%-73%) and 61.0% (95% CI, 51%-70%), respectively. Conclusions: Definitive radiation by use of inverse planned HDRB boost for locoregionally advanced cervical cancer is well tolerated and achieves excellent local control of disease. However, overall survival continues to be limited by the high rates of distant metastasis.« less

75 FR 42170 - Final Regulatory Guide: Issuance, Availability

Federal Register 2010, 2011, 2012, 2013, 2014

2010-07-20

..., techniques that the staff uses in evaluating specific problems or postulated accidents, and data that the... (EDEX) radiation exposures. These methods provide a conservative estimate of the EDEX and may be used to...

WE-DE-209-00: Practical Implementation of Deep Inspiration Breath Hold Techniques for Breast Radiation Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

First-in-man mesenchymal stem cells for radiation-induced xerostomia (MESRIX): study protocol for a randomized controlled trial.

PubMed

Grønhøj, Christian; Jensen, David H; Glovinski, Peter V; Jensen, Siri Beier; Bardow, Allan; Oliveri, Roberto S; Specht, Lena; Thomsen, Carsten; Darkner, Sune; Kiss, Katalin; Fischer-Nielsen, Anne; von Buchwald, Christian

2017-03-07

Salivary gland hypofunction and xerostomia are major complications following radiotherapy for head and neck cancer and may lead to debilitating oral disorders and impaired quality of life. Currently, only symptomatic treatment is available. However, mesenchymal stem cell (MSC) therapy has shown promising results in preclinical studies. Objectives are to assess safety and efficacy in a first-in-man trial on adipose-derived MSC therapy (ASC) for radiation-induced xerostomia. This is a single-center, phase I/II, randomized, placebo-controlled, double-blinded clinical trial. A total of 30 patients are randomized in a 1:1 ratio to receive ultrasound-guided, administered ASC or placebo to the submandibular glands. The primary outcome is change in unstimulated whole salivary flow rate. The secondary outcomes are safety, efficacy, change in quality of life, qualitative and quantitative measurements of saliva, as well as submandibular gland size, vascularization, fibrosis, and secretory tissue evaluation based on contrast-induced magnetic resonance imaging (MRI) and core-needle samples. The assessments are performed at baseline (1 month prior to treatment) and 1 and 4 months following investigational intervention. The trial is the first attempt to evaluate the safety and efficacy of adipose-derived MSCs (ASCs) in patients with radiation-induced xerostomia. The results may provide evidence for the effectiveness of ASC in patients with salivary gland hypofunction and xerostomia and deliver valuable information for the design of subsequent trials. EudraCT, Identifier: 2014-004349-29. Registered on 1 April 2015. ClinicalTrials.gov, Identifier: NCT02513238 . First received on 2 July 2015. The trial is prospectively registered.

Photosensitive adhesive bonding process of magnetooptic waveguides with Si guiding layer for optical nonreciprocal devices

NASA Astrophysics Data System (ADS)

Choowitsakunlert, Salinee; Takagiwa, Kenji; Kobashigawa, Takuya; Hosoya, Nariaki; Silapunt, Rardchawadee; Yokoi, Hideki

2018-05-01

A photosensitive adhesive bonding process for a magnetooptic waveguide for an optical isolator employing a nonreciprocal guided-radiation mode conversion is investigated at 1.55 µm. The magnetooptic waveguide is a straight rib type, and it is fabricated by bonding the Si guiding layer to a magnetic garnet. In the fabrication process, an adhesive material is diluted to obtain a certain thickness before depositing on a silicon-on-insulator (SOI) substrate. The relationship between the percent dilution ratio and the thickness of the adhesive layer is considered. The smallest gap thickness is found to be 0.66 µm at a dilution ratio of 2%.

Magnetic resonance spectroscopy-guided transperineal prostate biopsy and brachytherapy for recurrent prostate cancer.

PubMed

Barnes, Agnieszka Szot; Haker, Steven J; Mulkern, Robert V; So, Minna; D'Amico, Anthony V; Tempany, Clare M

2005-12-01

Brachytherapy targeted to the peripheral zone with magnetic resonance imaging (MRI) guidance is a prostate cancer treatment option with potentially fewer complications than other treatments. Follow-up MRI when failure is suspected is, however, difficult because of radiation-induced changes. Furthermore, MR spectroscopy (MRS) is compromised by susceptibility artifacts from radioactive seeds in the peripheral zone. We report a case in which combined MRI/MRS was useful for the detection of prostate cancer in the transitional zone in patients previously treated with MR-guided brachytherapy. We propose that MRI/MRS can help detect recurrent prostate cancer, guide prostate biopsy, and help manage salvage treatment decisions.

User`s and reference guide to the INEL RML/analytical radiochemistry sample tracking database version 1.00

DOE Office of Scientific and Technical Information (OSTI.GOV)

Femec, D.A.

This report discusses the sample tracking database in use at the Idaho National Engineering Laboratory (INEL) by the Radiation Measurements Laboratory (RML) and Analytical Radiochemistry. The database was designed in-house to meet the specific needs of the RML and Analytical Radiochemistry. The report consists of two parts, a user`s guide and a reference guide. The user`s guide presents some of the fundamentals needed by anyone who will be using the database via its user interface. The reference guide describes the design of both the database and the user interface. Briefly mentioned in the reference guide are the code-generating tools, CREATE-SCHEMAmore » and BUILD-SCREEN, written to automatically generate code for the database and its user interface. The appendices contain the input files used by the these tools to create code for the sample tracking database. The output files generated by these tools are also included in the appendices.« less

Next generation distal locking for intramedullary nails using an electromagnetic X-ray-radiation-free real-time navigation system.

PubMed

Hoffmann, Michael; Schröder, Malte; Lehmann, Wolfgang; Kammal, Michael; Rueger, Johannes Maria; Herrman Ruecker, Andreas

2012-07-01

Distal locking marks one challenging step during intramedullary nailing that can lead to an increased irradiation and prolonged operation times. The aim of this study was to evaluate the reliability and efficacy of an X-ray-radiation-free real-time navigation system for distal locking procedures. A prospective randomized cadaver study with 50 standard free-hand fluoroscopic-guided and 50 electromagnetic-guided distal locking procedures was performed. All procedures were timed using a stopwatch. Intraoperative fluoroscopy exposure time and absorbed radiation dose (mGy) readings were documented. All tibial nails were locked with two mediolateral and one anteroposterior screw. Successful distal locking was accomplished once correct placement of all three screws was confirmed. Successful distal locking was achieved in 98 cases. No complications were encountered using the electromagnetic navigation system. Eight complications arose during free-hand fluoroscopic distal locking. Undetected secondary drill slippage on the ipsilateral cortex accounted for most problems followed by undetected intradrilling misdirection causing a fissural fracture of the contralateral cortex while screw insertion in one case. Compared with the free-hand fluoroscopic technique, electromagnetically navigated distal locking provides a median time benefit of 244 seconds without using ionizing radiation. Compared with the standard free-hand fluoroscopic technique, the electromagnetic guidance system used in this study showed high reliability and was associated with less complications, took significantly less time, and used no radiation exposure for distal locking procedures. Therapeutic study, level II.

Evaluation of Novel 64Cu-Labeled Theranostic Gadolinium-Based Nanoprobes in HepG2 Tumor-Bearing Nude Mice.

PubMed

Hu, Pengcheng; Cheng, Dengfeng; Huang, Tao; Banizs, Anna B; Xiao, Jie; Liu, Guobing; Chen, Quan; Wang, Yuenan; He, Jiang; Shi, Hongcheng

2017-09-06

Radiation therapy of liver cancer is limited by low tolerance of the liver to radiation. Radiosensitizers can effectively reduce the required radiation dose. AGuIX nanoparticles are small, multifunctional gadolinium-based nanoparticles that can carry radioisotopes or fluorescent markers for single-photon emission computed tomography (SPECT), positron emission tomography (PET), fluorescence imaging, and even multimodality imaging. In addition, due to the high atomic number of gadolinium, it can also serve as a tumor radiation sensitizer. It is critical to define the biodistribution and pharmacokinetics of these gadolinium-based nanoparticles to quantitate the magnitude and duration of their retention within the tumor microenvironment during radiotherapy. Therefore, in this study, we successfully labeled AGuIX with 64 Cu through the convenient built-in chelator. The biodistribution studies indicated that the radiotracer 64 Cu-AGuIX accumulates to high levels in the HepG2 xenograft of nude mice, suggesting that it would be a potential theranostic nanoprobe for image-guided radiotherapy in HCC. We also used a transmission electron microscope to confirm AGuIX uptake in the HepG2 cells. In radiation therapy studies, a decrease in 18 F-FDG uptake was observed in the xenografts of the nude mice irradiated with AGuIX, which was injected 1 h before. These results provide proof-of-concept that AGuIX can be used as a theranostic radiosensitizer for PET imaging to guide radiotherapy for liver cancer.

Evaluation of Novel 64Cu-Labeled Theranostic Gadolinium-Based Nanoprobes in HepG2 Tumor-Bearing Nude Mice

NASA Astrophysics Data System (ADS)

Hu, Pengcheng; Cheng, Dengfeng; Huang, Tao; Banizs, Anna B.; Xiao, Jie; Liu, Guobing; Chen, Quan; Wang, Yuenan; He, Jiang; Shi, Hongcheng

2017-09-01

Radiation therapy of liver cancer is limited by low tolerance of the liver to radiation. Radiosensitizers can effectively reduce the required radiation dose. AGuIX nanoparticles are small, multifunctional gadolinium-based nanoparticles that can carry radioisotopes or fluorescent markers for single-photon emission computed tomography (SPECT), positron emission tomography (PET), fluorescence imaging, and even multimodality imaging. In addition, due to the high atomic number of gadolinium, it can also serve as a tumor radiation sensitizer. It is critical to define the biodistribution and pharmacokinetics of these gadolinium-based nanoparticles to quantitate the magnitude and duration of their retention within the tumor microenvironment during radiotherapy. Therefore, in this study, we successfully labeled AGuIX with 64Cu through the convenient built-in chelator. The biodistribution studies indicated that the radiotracer 64Cu-AGuIX accumulates to high levels in the HepG2 xenograft of nude mice, suggesting that it would be a potential theranostic nanoprobe for image-guided radiotherapy in HCC. We also used a transmission electron microscope to confirm AGuIX uptake in the HepG2 cells. In radiation therapy studies, a decrease in 18F-FDG uptake was observed in the xenografts of the nude mice irradiated with AGuIX, which was injected 1 h before. These results provide proof-of-concept that AGuIX can be used as a theranostic radiosensitizer for PET imaging to guide radiotherapy for liver cancer.

Radiation exposure--do urologists take it seriously in Turkey?

PubMed

Söylemez, Haluk; Altunoluk, Bülent; Bozkurt, Yaşar; Sancaktutar, Ahmet Ali; Penbegül, Necmettin; Atar, Murat

2012-04-01

A questionnaire was administered to urologists to evaluate attitudes and behaviors about protection from radiation exposure during fluoroscopy guided endourological procedures. The questionnaire was e-mailed to 1,482 urologists, including urology residents, specialists and urologists holding all levels of academic degrees, between May and June 2011. The questionnaire administered to study participants was composed of demographic questions, and questions on radiation exposure frequency, and the use of dosimeters and flexible protective clothes. If a respondent reported not using dosimeters or protective clothes, additional questions asked for the reason. Of the 1,482 questionnaires 394 (26.58%) were returned, of which 363 had completed answers. A total of 307 physicians (84.58%) were exposed to ionizing radiation, of whom 79.61% stated that they perform percutaneous nephrolithotomy at the clinic. Fluoroscopy guidance was the initial choice of 96.19% of urologists during percutaneous nephrolithotomy. Despite the common use of lead aprons (75.24%) most urologists did not use dosimeters (73.94%), eyeglasses (76.95%) or gloves (66.67%) while 46.44% always used thyroid shields during fluoroscopy. When asked why they did not use protective clothing, the most common answers were that protective clothes are not ergonomic and not practical. Results clearly highlight the lack of use of ionizing radiation protection devices and dosimeters during commonly performed fluoroscopy guided endourological procedures among urologists in Turkey. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

A compact tunable polarized X-ray source based on laser-plasma helical undulators

PubMed Central

Luo, J.; Chen, M.; Zeng, M.; Vieira, J.; Yu, L. L.; Weng, S. M.; Silva, L. O.; Jaroszynski, D. A.; Sheng, Z. M.; Zhang, J.

2016-01-01

Laser wakefield accelerators have great potential as the basis for next generation compact radiation sources because of their extremely high accelerating gradients. However, X-ray radiation from such devices still lacks tunability, especially of the intensity and polarization distributions. Here we propose a tunable polarized radiation source based on a helical plasma undulator in a plasma channel guided wakefield accelerator. When a laser pulse is initially incident with a skew angle relative to the channel axis, the laser and accelerated electrons experience collective spiral motions, which leads to elliptically polarized synchrotron-like radiation with flexible tunability on radiation intensity, spectra and polarization. We demonstrate that a radiation source with millimeter size and peak brilliance of 2 × 1019 photons/s/mm2/mrad2/0.1% bandwidth can be made with moderate laser and electron beam parameters. This brilliance is comparable with third generation synchrotron radiation facilities running at similar photon energies, suggesting that laser plasma based radiation sources are promising for advanced applications. PMID:27377126

Emergency department management of patients internally contaminated with radioactive material

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kazzi, Ziad; Buzzell, Jennifer; Bertelli, Luiz

After a radiation emergency that involves the dispersal of radioactive material, patients can become externally and internally contaminated with one or more radionuclides. Internal contamination can lead to the delivery of harmful ionizing radiation doses to various organs and tissues or the whole body. The clinical consequences can range from acute radiation syndrome (ARS) to the long term development of cancer. Estimating the amount of radioactive material absorbed into the body can guide the management of patients. Treatment includes, in addition to supportive care and long term monitoring, certain medical countermeasures like Prussian blue, Calcium DTPA and Zinc DTPA.

Emergency department management of patients internally contaminated with radioactive material

DOE PAGES

Kazzi, Ziad; Buzzell, Jennifer; Bertelli, Luiz; ...

2014-11-15

After a radiation emergency that involves the dispersal of radioactive material, patients can become externally and internally contaminated with one or more radionuclides. Internal contamination can lead to the delivery of harmful ionizing radiation doses to various organs and tissues or the whole body. The clinical consequences can range from acute radiation syndrome (ARS) to the long term development of cancer. Estimating the amount of radioactive material absorbed into the body can guide the management of patients. Treatment includes, in addition to supportive care and long term monitoring, certain medical countermeasures like Prussian blue, Calcium DTPA and Zinc DTPA.

Microbend fiber-optic chemical sensor

DOEpatents

Weiss, Jonathan D.

2002-01-01

A microbend fiber-optic chemical sensor for detecting chemicals in a sample, and a method for its use, is disclosed. The sensor comprises at least one optical fiber having a microbend section (a section of small undulations in its axis), for transmitting and receiving light. In transmission, light guided through the microbend section scatters out of the fiber core and interacts, either directly or indirectly, with the chemical in the sample, inducing fluorescence radiation. Fluorescence radiation is scattered back into the microbend section and returned to an optical detector for determining characteristics of the fluorescence radiation quantifying the presence of a specific chemical.

Editorial: ERCP-Related Radiation Cataractogenesis: Is It Time to Be Concerned?

PubMed

Mekaroonkamol, Parit; Keilin, Steven

2017-05-01

With the growing number of fluoroscopic guided endoscopic procedures, radiation-related risk needs to be further assessed. Recent evidence indicates that radiation cataractogenesis occurs at a lower dose threshold than previously believed. While body aprons and thyroid shields are well-established standard protection during fluoroscopy, ocular safety and the use of protective eyewear are not as well defined. This prospective study answered two important questions: Does the standard body dosimeter provide an accurate ocular dosimetry? And what is the time of fluoroscopy needed to warrant using lens protection? It also raises the question whether current guidelines need to be updated.

Teaching basic trauma: validating FluoroSim, a digital fluoroscopic simulator for guide-wire insertion in hip surgery.

PubMed

Sugand, Kapil; Wescott, Robert A; Carrington, Richard; Hart, Alister; Van Duren, Bernard H

2018-05-10

Background and purpose - Simulation is an adjunct to surgical education. However, nothing can accurately simulate fluoroscopic procedures in orthopedic trauma. Current options for training with fluoroscopy are either intraoperative, which risks radiation, or use of expensive and unrealistic virtual reality simulators. We introduce FluoroSim, an inexpensive digital fluoroscopy simulator without the need for radiation. Patients and methods - This was a multicenter study with 26 surgeons in which everyone completed 1 attempt at inserting a guide-wire into a femoral dry bone using surgical equipment and FluoroSim. 5 objective performance metrics were recorded in real-time to assess construct validity. The surgeons were categorized based on the number of dynamic hip screws (DHS) performed: novices (< 10), intermediates (10-39) and experts (≥ 40). A 7-point Likert scale questionnaire assessed the face and content validity of FluoroSim. Results - Construct validity was present for 2 clinically validated metrics in DHS surgery. Experts and intermediates statistically significantly outperformed novices for tip-apex distance and for cut-out rate. Novices took the least number of radiographs. Face and content validity were also observed. Interpretation - FluoroSim discriminated between novice and intermediate or expert surgeons based on tip-apex distance and cut-out rate while demonstrating face and content validity. FluoroSim provides a useful adjunct to orthopedic training. Our findings concur with results from studies using other simulation modalities. FluoroSim can be implemented for education easily and cheaply away from theater in a safe and controlled environment.

Development of an MRI-Guided Intra-Prostatic Needle Placement System

DTIC Science & Technology

2011-07-01

and intra-operative imaging using techniques such as those described by Haker , et al. [18]. Target points for the needle insertion are selected... Haker , S., Fichtinger, G., Tem- pany, C.: Transperineal prostate biopsy under magnetic resonance image guid- ance: A needle placement accuracy study 26...clinically localized prostate cancer. Int J Radiat Oncol Biol Phys 42(3), 507–515 (1998) 9. DiMaio, S.P., Pieper, S., Chinzei, K., Hata, N., Haker , S.J

Efficient solar-pumped Nd:YAG laser by a double-stage light-guide/V-groove cavity

NASA Astrophysics Data System (ADS)

Almeida, Joana; Liang, Dawei

2011-05-01

Since the first reported Nd:YAG solar laser, researchers have been exploiting parabolic mirrors and heliostats for enhancing laser output performance. We are now investigating the production of an efficient solar-pumped laser for the reduction of magnesium from magnesium oxide, which could be an alternative solution to fossil fuel. Therefore both high conversion efficiency and excellent beam quality are imperative. By using a single fused silica light guide of rectangular cross section, highly concentrated solar radiation at the focal spot of a stationary parabolic mirror is efficiently transferred to a water-flooded V-groove pump cavity. It allows for the double-pass absorption of pump light along a 4mm diameter, 30mm length, 1.1at% Nd:YAG rod. Optimum pumping parameters and solar laser output power are found through ZEMAXTM non-sequential ray-tracing and LASCADTM laser cavity analysis. 11.0 W of multimode laser output power with excellent beam profile is numerically calculated, corresponding to 6.1W/m2 collection efficiency. To validate the proposed pumping scheme, an experimental setup of the double-stage light-guide/V-groove cavity was built. 78% of highly concentrated solar radiation was efficiently transmitted by the fused silica light guide. The proposed pumping scheme can be an effective solution for enhancing solar laser performances when compared to other side-pump configurations.

Dosimetric evaluation of the OneDoseTM MOSFET for measuring kilovoltage imaging dose from image-guided radiotherapy procedures.

PubMed

Ding, George X; Coffey, Charles W

2010-09-01

The purpose of this study is to investigate the feasibility of using a single-use dosimeter, OneDose MOSFET designed for in vivo patient dosimetry, for measuring the radiation dose from kilovoltage (kV) x rays resulting from image-guided procedures. The OneDose MOSFET dosimeters were precalibrated by the manufacturer using Co-60 beams. Their energy response and characteristics for kV x rays were investigated by using an ionization chamber, in which the air-kerma calibration factors were obtained from an Accredited Dosimetry Calibration Laboratory (ADCL). The dosimetric properties have been tested for typical kV beams used in image-guided radiation therapy (IGRT). The direct dose reading from the OneDose system needs to be multiplied by a correction factor ranging from 0.30 to 0.35 for kilovoltage x rays ranging from 50 to 125 kVp, respectively. In addition to energy response, the OneDose dosimeter has up to a 20% reduced sensitivity for beams (70-125 kVp) incident from the back of the OneDose detector. The uncertainty in measuring dose resulting from a kilovoltage beam used in IGRT is approximately 20%; this uncertainty is mainly due to the sensitivity dependence of the incident beam direction relative to the OneDose detector. The ease of use may allow the dosimeter to be suitable for estimating the dose resulting from image-guided procedures.

Strategic planning in an academic radiation medicine program.

PubMed

Hamilton, J L; Foxcroft, S; Moyo, E; Cooke-Lauder, J; Spence, T; Zahedi, P; Bezjak, A; Jaffray, D; Lam, C; Létourneau, D; Milosevic, M; Tsang, R; Wong, R; Liu, F F

2017-12-01

In this paper, we report on the process of strategic planning in the Radiation Medicine Program (rmp) at the Princess Margaret Cancer Centre. The rmp conducted a strategic planning exercise to ensure that program priorities reflect the current health care environment, enable nimble responses to the increasing burden of cancer, and guide program operations until 2020. Data collection was guided by a project charter that outlined the project goal and the roles and responsibilities of all participants. The process was managed by a multidisciplinary steering committee under the guidance of an external consultant and consisted of reviewing strategic planning documents from close collaborators and institutional partners, conducting interviews with key stakeholders, deploying a program-wide survey, facilitating an anonymous and confidential e-mail feedback box, and collecting information from group deliberations. The process of strategic planning took place from December 2014 to December 2015. Mission and vision statements were developed, and core values were defined. A final document, Strategic Roadmap to 2020, was established to guide programmatic pursuits during the ensuing 5 years, and an implementation plan was developed to guide the first year of operations. The strategic planning process provided an opportunity to mobilize staff talents and identify environmental opportunities, and helped to enable more effective use of resources in a rapidly changing health care environment. The process was valuable in allowing staff to consider and discuss the future, and in identifying strategic issues of the greatest importance to the program. Academic programs with similar mandates might find our report useful in guiding similar processes in their own organizations.

Strategic planning in an academic radiation medicine program

PubMed Central

Hamilton, J.L.; Foxcroft, S.; Moyo, E.; Cooke-Lauder, J.; Spence, T.; Zahedi, P.; Bezjak, A.; Jaffray, D.; Lam, C.; Létourneau, D.; Milosevic, M.; Tsang, R.; Wong, R.; Liu, F.F.

2017-01-01

Background In this paper, we report on the process of strategic planning in the Radiation Medicine Program (rmp) at the Princess Margaret Cancer Centre. The rmp conducted a strategic planning exercise to ensure that program priorities reflect the current health care environment, enable nimble responses to the increasing burden of cancer, and guide program operations until 2020. Methods Data collection was guided by a project charter that outlined the project goal and the roles and responsibilities of all participants. The process was managed by a multidisciplinary steering committee under the guidance of an external consultant and consisted of reviewing strategic planning documents from close collaborators and institutional partners, conducting interviews with key stakeholders, deploying a program-wide survey, facilitating an anonymous and confidential e-mail feedback box, and collecting information from group deliberations. Results The process of strategic planning took place from December 2014 to December 2015. Mission and vision statements were developed, and core values were defined. A final document, Strategic Roadmap to 2020, was established to guide programmatic pursuits during the ensuing 5 years, and an implementation plan was developed to guide the first year of operations. Conclusions The strategic planning process provided an opportunity to mobilize staff talents and identify environmental opportunities, and helped to enable more effective use of resources in a rapidly changing health care environment. The process was valuable in allowing staff to consider and discuss the future, and in identifying strategic issues of the greatest importance to the program. Academic programs with similar mandates might find our report useful in guiding similar processes in their own organizations. PMID:29270061

Guidance: The practical management of the gastrointestinal symptoms of pelvic radiation disease

PubMed Central

Andreyev, H Jervoise N; Muls, Ann C; Norton, Christine; Ralph, Charlotte; Watson, Lorraine; Shaw, Clare; Lindsay, James O

2015-01-01

Background A recent randomised trial suggested that an algorithmic approach to investigating and managing gastrointestinal symptoms of pelvic radiation disease (PRD) is beneficial and that specially trained nurses can manage patients as effectively as a gastroenterologist. Aims The aim of the development and peer review of the guide was to make the algorithm used in the trial accessible to all levels of clinician. Methods Experts who manage patients with PRD were asked to review the guide, rating each section for agreement with the recommended measures and suggesting amendments if necessary. Specific comments were discussed and incorporated as appropriate, and this process was repeated for a second round of review. Results 34 gastroenterologists, 10 nurses, 9 dietitians, 7 surgeons and 5 clinical oncologists participated in round one. Consensus (defined prospectively as 60% or more panellists selecting ‘strongly agree’ or ‘agree’) was reached for 27 of the original 28 sections in the guide, with a median of 75% of panellists agreeing with each section. 86% of panellists agreed that the guide was acceptable for publication or acceptable with minor revisions. 55 of the original 65 panellists participated in round two. 89% agreed it was acceptable for publication after the first revision. Further minor amendments were made in response to round two. Conclusions Development of the guide in response to feedback included ▸ improvement of occasional algorithmic steps ▸ a more user-friendly layout ▸ clearer timeframes for referral to other teams ▸ expansion of reference list ▸ addition of procedures to the appendix. PMID:25580207

Ultrasound-guided lumbar puncture in pediatric patients: technical success and safety.

PubMed

Pierce, David B; Shivaram, Giri; Koo, Kevin S H; Shaw, Dennis W W; Meyer, Kirby F; Monroe, Eric J

2018-06-01

Disadvantages of fluoroscopically guided lumbar puncture include delivery of ionizing radiation and limited resolution of incompletely ossified posterior elements. Ultrasound (US) allows visualization of critical soft tissues and the cerebrospinal fluid (CSF) space without ionizing radiation. To determine the technical success and safety of US-guided lumbar puncture in pediatric patients. A retrospective review identified all patients referred to interventional radiology for lumbar puncture between June 2010 and June 2017. Patients who underwent lumbar puncture with fluoroscopic guidance alone were excluded. For the remaining procedures, technical success and procedural complications were assessed. Two hundred and one image-guided lumbar punctures in 161 patients were included. Eighty patients (43%) had previously failed landmark-based attempts. One hundred ninety-six (97.5%) patients underwent lumbar puncture. Five procedures (2.5%) were not attempted after US assessment, either due to a paucity of CSF or unsafe window for needle placement. Technical success was achieved in 187 (95.4%) of lumbar punctures attempted with US guidance. One hundred seventy-seven (90.3%) were technically successful with US alone (age range: 2 days-15 years, weight range: 1.9-53.1 kg) and an additional 10 (5.1%) were successful with US-guided thecal access and subsequent fluoroscopic confirmation. Three (1.5%) cases were unsuccessful with US guidance but were subsequently successful with fluoroscopic guidance. Of the 80 previously failed landmark-based lumbar punctures, 77 (96.3%) were successful with US guidance alone. There were no reported complications. US guidance is safe and effective for lumbar punctures and has specific advantages over fluoroscopy in pediatric patients.

Comparison of CT Fluoroscopy-Guided Manual and CT-Guided Robotic Positioning System for In Vivo Needle Placements in Swine Liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cornelis, F.; Takaki, H.; Laskhmanan, M.

PurposeTo compare CT fluoroscopy-guided manual and CT-guided robotic positioning system (RPS)-assisted needle placement by experienced IR physicians to targets in swine liver.Materials and MethodsManual and RPS-assisted needle placement was performed by six experienced IR physicians to four 5 mm fiducial seeds placed in swine liver (n = 6). Placement performance was assessed for placement accuracy, procedure time, number of confirmatory scans, needle manipulations, and procedure radiation dose. Intra-modality difference in performance for each physician was assessed using paired t test. Inter-physician performance variation for each modality was analyzed using Kruskal–Wallis test.ResultsPaired comparison of manual and RPS-assisted placements to a target by the samemore » physician indicated accuracy outcomes was not statistically different (manual: 4.53 mm; RPS: 4.66 mm; p = 0.41), but manual placement resulted in higher total radiation dose (manual: 1075.77 mGy/cm; RPS: 636.4 mGy/cm; p = 0.03), required more confirmation scans (manual: 6.6; RPS: 1.6; p < 0.0001) and needle manipulations (manual: 4.6; RPS: 0.4; p < 0.0001). Procedure time for RPS was longer than manual placement (manual: 6.12 min; RPS: 9.7 min; p = 0.0003). Comparison of inter-physician performance during manual placement indicated significant differences in the time taken to complete placements (p = 0.008) and number of repositions (p = 0.04) but not in other study measures (p > 0.05). Comparison of inter-physician performance during RPS-assisted placement suggested statistically significant differences in procedure time (p = 0.02) and not in other study measures (p > 0.05).ConclusionsCT-guided RPS-assisted needle placement reduced radiation dose, number of confirmatory scans, and needle manipulations when compared to manual needle placement by experienced IR physicians, with equivalent accuracy.« less

Image-Guided Hypofractionated Radiation Therapy With Stereotactic Body Radiation Therapy Boost and Combination Chemotherapy in Treating Patients With Stage II-III Non-Small Cell Lung Cancer That Cannot Be Removed By Surgery

ClinicalTrials.gov

2017-06-12

Adenocarcinoma of the Lung; Adenosquamous Cell Lung Cancer; Large Cell Lung Cancer; Recurrent Non-small Cell Lung Cancer; Squamous Cell Lung Cancer; Stage IIA Non-small Cell Lung Cancer; Stage IIB Non-small Cell Lung Cancer; Stage IIIA Non-small Cell Lung Cancer; Stage IIIB Non-small Cell Lung Cancer

EPRI guide to managing nuclear utility protective clothing programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kelly, J.J.

1991-05-01

The Electric Power Research Institute (EPRI) commissioned a radioactive waste related project (RP2414-34) during the last quarter of 1989 to produce a guide for developing and managing nuclear protective clothing programs. Every nuclear facility must coordinate some type of protective clothing program for its radiation workers to insure proper and safe protection for the wearer and to maintain control over the spread of contamination. Yet, every nuclear facility has developed its own unique program for managing such clothing. Accordingly, a need existed for a reference guide to assist with the standardization of protective clothing programs and to assist in controllingmore » the potentially runaway economics of such programs. This document is the first known effort to formalize the planning and economic factors surrounding a nuclear utility protective clothing program. It is intended to be informative by addressing the various pieces of information necessary to establish and maintain an effective, professionally managed protective clothing program. It also attempts to provide guidance toward tailoring the information and providing examples within the report to fit each utility's specific needs. This report is further intended to address new issues and trends occurring throughout the nuclear industry in late 1989 which can have either a significant positive or negative impact on the operations or economics of nuclear protective clothing programs. 1 ref., 11 tabs.« less

Biomarker-guided screening of Juzen-taiho-to, an oriental herbal formulation for immunostimulation.

PubMed

Takaoka, Anna; Iacovidou, Maria; Hasson, Tal H; Montenegro, Diego; Li, Xiangming; Tsuji, Moriya; Kawamura, Akira

2014-03-01

Juzen-taiho-to is an immunostimulatory herbal formulation that is clinically used in East Asia for cancer patients undergoing chemotherapy and radiation. The formulation stimulates various leukocytes, including T, B, and NK cells and macrophages. Although Juzen-taiho-to is known to contain numerous compounds with various pharmacological activities, it is not clear which compounds are responsible for the stimulation of individual cell types. Here, we conducted what we call "biomarker-guided screening" to purify compounds responsible for the macrophages stimulatory activity. To this end, gene expression was analyzed by a DNA array for macrophages treated with Juzen-taiho-to and DMSO (vehicle control), which identified intercellular adhesion molecule 1 as a biomarker of macrophage stimulation by Juzen-taiho-to. A quantitative reverse transcription polymerase chain reaction assay of intercellular adhesion molecule 1 was then used to guide the purification of active compounds. The screening resulted in the purification of a glycolipid mixture, containing β-glucosylceramides. The glycolipid mixture potently stimulated intercellular adhesion molecule 1 expression in primary dendritic cells as well as in primary CD14+ (macrophages) cells. The identification of this glycolipid mixture opens up an opportunity for further studies to understand how plant-derived glycolipids stimulate macrophages and dendritic cells in a safe and effective manner as demonstrated by Juzen-taiho-to. Georg Thieme Verlag KG Stuttgart · New York.

Reliability-Based Electronics Shielding Design Tools

NASA Technical Reports Server (NTRS)

Wilson, J. W.; O'Neill, P. J.; Zang, T. A.; Pandolf, J. E.; Tripathi, R. K.; Koontz, Steven L.; Boeder, P.; Reddell, B.; Pankop, C.

2007-01-01

Shielding design on large human-rated systems allows minimization of radiation impact on electronic systems. Shielding design tools require adequate methods for evaluation of design layouts, guiding qualification testing, and adequate follow-up on final design evaluation.

WE-DE-209-02: Active Breathing Control

DOE Office of Scientific and Technical Information (OSTI.GOV)

Comsa, D.

Breast radiation therapy is associated with some risk of lung toxicity as well as cardiac toxicity for left-sided cases. Radiation doses to the lung and heart can be reduced by using the deep inspiration breath hold (DIBH) technique, in which the patient is simulated and treated during the deep inspiration phase of the breathing cycle. During DIBH, the heart is usually displaced posteriorly, inferiorly, and to the right, effectively expanding the distance between the heart and the breast/chest wall. As a result, the distance between the medial treatment field border and heart/lung is increased. Also, in a majority of DIBHmore » patients, the air drawn into the thoracic cavity increases the total lung volume. The DIBH was discussed by an AAPM Task Group 10 years ago in the AAPM TG 76 report. However, DIBH is still not the standard of care in many clinics, which may be partially due to challenges associated with its implementation. Therefore, this seccion will focus primarily on how to clinically implement four different DIBH techniques: (1) Active Breathing Control, (2) Spirometric Motion Management, (3) 3D Surface Image-Guided, and (4) Self-held Breath Control with Respiratory Monitoring and Feedback Guidance. Learning Objectives: Describe the physical displacement of the heart and the change in lung volume during DIBH and discuss dosimetric consequences of those changes. Provide an overview of the technical aspects. Describe work flow for patient simulation and treatment. Give an overview of commissioning and routine. Provide practical tips for clinical implementation.« less

Terminal Sliding Mode Tracking Controller Design for Automatic Guided Vehicle

NASA Astrophysics Data System (ADS)

Chen, Hongbin

2018-03-01

Based on sliding mode variable structure control theory, the path tracking problem of automatic guided vehicle is studied, proposed a controller design method based on the terminal sliding mode. First of all, through analyzing the characteristics of the automatic guided vehicle movement, the kinematics model is presented. Then to improve the traditional expression of terminal sliding mode, design a nonlinear sliding mode which the convergence speed is faster than the former, verified by theoretical analysis, the design of sliding mode is steady and fast convergence in the limited time. Finally combining Lyapunov method to design the tracking control law of automatic guided vehicle, the controller can make the automatic guided vehicle track the desired trajectory in the global sense as well as in finite time. The simulation results verify the correctness and effectiveness of the control law.

Electromagnetic Real Time Navigation in the Region of the Posterior Pelvic Ring: An Experimental In-Vitro Feasibility Study and Comparison of Image Guided Techniques.

PubMed

Pishnamaz, Miguel; Wilkmann, Christoph; Na, Hong-Sik; Pfeffer, Jochen; Hänisch, Christoph; Janssen, Max; Bruners, Philipp; Kobbe, Philipp; Hildebrand, Frank; Schmitz-Rode, Thomas; Pape, Hans-Christoph

2016-01-01

Electromagnetic tracking is a relatively new technique that allows real time navigation in the absence of radiation. The aim of this study was to prove the feasibility of this technique for the treatment of posterior pelvic ring fractures and to compare the results with established image guided procedures. Tests were performed in pelvic specimens (Sawbones®) with standardized sacral fractures (Type Denis I or II). A gel matrix simulated the operative approach and a cover was used to disable visual control. The electromagnetic setup was performed by using a custom made carbon reference plate and a prototype stainless steel K-wire with an integrated sensor coil. Four different test series were performed: Group OCT: Optical navigation using preoperative CT-scans; group O3D: Optical navigation using intraoperative 3-D-fluoroscopy; group Fluoro: Conventional 2-D-fluoroscopy; group EMT: Electromagnetic navigation combined with a preoperative Dyna-CT. Accuracy of screw placement was analyzed by standardized postoperative CT-scan for each specimen. Operation time and intraoperative radiation exposure for the surgeon was documented. All data was analyzed using SPSS (Version 20, 76 Chicago, IL, USA). Statistical significance was defined as p< 0.05. 160 iliosacral screws were placed (40 per group). EMT resulted in a significantly higher incidence of optimal screw placement (EMT: 36/40) compared to the groups Fluoro (30/40; p< 0.05) and OCT (31/40; p< 0.05). Results between EMT and O3D were comparable (O3D: 37/40; n.s.). Also, the operation time was comparable between groups EMT and O3D (EMT 7.62 min vs. O3D 7.98 min; n.s.), while the surgical time was significantly shorter compared to the Fluoro group (10.69 min; p< 0.001) and the OCT group (13.3 min; p< 0.001). Electromagnetic guided iliosacral screw placement is a feasible procedure. In our experimental setup, this method was associated with improved accuracy of screw placement and shorter operation time when compared with the conventional fluoroscopy guided technique and compared to the optical navigation using preoperative CT-scans. Further studies are necessary to rule out drawbacks of this technique regarding ferromagnetic objects.

Manipulation by multiple filamentation of subpicosecond TW KrF laser beam

NASA Astrophysics Data System (ADS)

Zvorykin, V. D.; Smetanin, I. V.; Ustinovskii, N. N.; Shutov, A. V.

2018-05-01

A self-focusing of TW-level subpicosecond UV KrF laser pulses in ambient air produces a few 100 randomly distributed filaments over 100-m propagation distance. A control of multiple filamentation process by a number of methods was demonstrated in the present work envisaging applications for a HV discharge guiding, remote excitation of an atmospheric air laser, MW radiation transfer by virtual plasma waveguide, as well as filamentation suppression to improve short pulse parameters in direct amplification scheme. Under the laser beam focusing, a multitude of filaments coalesced into a superfilament with highly increased intensity and plasma conductivity. A superradiant forward lasing was obtained in the superfilament around 1.07-µm wavelength of atmospheric nitrogen. A regular 2D array of a 100 superfilaments was configured over 20-m distance by Fresnel diffraction on periodic amplitude masks. Effective Kerr defocusing and a subsequent filaments suppression over 50-m distance was demonstrated in Xe due to 2-photon resonance of laser radiation with 6p state being accompanied by a narrow-angle coherent conical emission at 828-nm wavelength.

A study on pseudo interface wave technique for CRDM weld defects in nuclear power plants

NASA Astrophysics Data System (ADS)

Lee, Jaesun; Park, Junpil; Cho, Younho; Huh, Hyung; Park, Keun-Bae; Kim, Dong-Ok

2015-03-01

The nuclear power plant inspection is very important for the safety issue. However due to some radiation and geometric problems, the detection of CRDM(Control Rod Drive Mechanism) can be very difficult by using conventional Ultrasonic Testing method. Also the shrink fit boundary condition can also be an obstacle for the inspection in this paper, instead of conventional Ultrasonic Testing, guided wave was used for the detection of some complicated structures. The CRDM nozzle was installed in reactor head with perfect shrink fit condition by using stainless steel. The wave amplitude distribution on the circumferential direction was calculated with various boundary conditions and the experimental result shows a possibility of the defect detection on J-groove weld.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schnapauff, Dirk, E-mail: dirk.schnapauff@charite.de; Denecke, Timm; Grieser, Christian

Purpose: This study was designed to investigate the clinical outcome of patients with irresectable, intrahepatic cholangiocarcinoma (IHC) treated with computed tomography (CT)-guided HDR-brachytherapy (CT-HDRBT) for local tumor ablation.MethodFifteen consecutive patients with histologically proven cholangiocarcinoma were selected for this retrospective study. Patients were treated by high-dose-rate internal brachytherapy (HDRBT) using an Iridium-192 source in afterloading technique through CT-guided percutaneous placed catheters. A total of 27 brachytherapy treatments were performed in these patients between 2006 and 2009. Median tumor enclosing target dose was 20 Gy, and mean target volume of the radiated tumors was 131 ({+-} 90) ml (range, 10-257 ml). Follow-upmore » consisted of clinical visits and magnetic resonance imaging of the liver every third month. Statistical evaluation included survival analysis using the Kaplan-Meier method. Results: After a median follow-up of 18 (range, 1-27) months after local ablation, 6 of the 15 patients are still alive; 4 of them did not get further chemotherapy and are regarded as disease-free. The reached median local tumor control was 10 months; median local tumor control, including repetitive local ablation, was 11 months. Median survival after local ablation was 14 months and after primary diagnosis 21 months. Conclusion: In view of current clinical data on the clinical outcome of cholangiocarcinoma, locally ablative treatment with CT-HDRBT represents a promising and safe technique for patients who are not eligible for tumor resection.« less

Adaptive acoustic energy delivery to near and far fields using foldable, tessellated star transducers

NASA Astrophysics Data System (ADS)

Zou, Chengzhe; Harne, Ryan L.

2017-05-01

Methods of guiding acoustic energy arbitrarily through space have long relied on digital controls to meet performance needs. Yet, more recent attention to adaptive structures with unique spatial configurations has motivated mechanical signal processing (MSP) concepts that may not be subjected to the same functional and performance limitations as digital acoustic beamforming counterparts. The periodicity of repeatable structural reconfiguration enabled by origami-inspired tessellated architectures turns attention to foldable platforms as frameworks for MSP development. This research harnesses principles of MSP to study a tessellated, star-shaped acoustic transducer constituent that provides on-demand control of acoustic energy guiding via folding-induced shape reconfiguration. An analytical framework is established to probe the roles of mechanical and acoustic geometry on the far field directivity and near field focusing of sound energy. Following validation by experiments and verification by simulations, parametric studies are undertaken to uncover relations between constituent topology and acoustic energy delivery to arbitrary points in the free field. The adaptations enabled by folding of the star-shaped transducer reveal capability for restricting sound energy to angular regions in the far field while also introducing means to modulate sound energy by three orders-of-magnitude to locations near to the transducer surface. In addition, the modeling philosophy devised here provides a valuable approach to solve general sound radiation problems for foldable, tessellated acoustic transducer constituents of arbitrary geometry.

Half-Fan-Based Intensity-Weighted Region-of-Interest Imaging for Low-Dose Cone-Beam CT in Image-Guided Radiation Therapy.

PubMed

Yoo, Boyeol; Son, Kihong; Pua, Rizza; Kim, Jinsung; Solodov, Alexander; Cho, Seungryong

2016-10-01

With the increased use of computed tomography (CT) in clinics, dose reduction is the most important feature people seek when considering new CT techniques or applications. We developed an intensity-weighted region-of-interest (IWROI) imaging method in an exact half-fan geometry to reduce the imaging radiation dose to patients in cone-beam CT (CBCT) for image-guided radiation therapy (IGRT). While dose reduction is highly desirable, preserving the high-quality images of the ROI is also important for target localization in IGRT. An intensity-weighting (IW) filter made of copper was mounted in place of a bowtie filter on the X-ray tube unit of an on-board imager (OBI) system such that the filter can substantially reduce radiation exposure to the outer ROI. In addition to mounting the IW filter, the lead-blade collimation of the OBI was adjusted to produce an exact half-fan scanning geometry for a further reduction of the radiation dose. The chord-based rebinned backprojection-filtration (BPF) algorithm in circular CBCT was implemented for image reconstruction, and a humanoid pelvis phantom was used for the IWROI imaging experiment. The IWROI image of the phantom was successfully reconstructed after beam-quality correction, and it was registered to the reference image within an acceptable level of tolerance. Dosimetric measurements revealed that the dose is reduced by approximately 61% in the inner ROI and by 73% in the outer ROI compared to the conventional bowtie filter-based half-fan scan. The IWROI method substantially reduces the imaging radiation dose and provides reconstructed images with an acceptable level of quality for patient setup and target localization. The proposed half-fan-based IWROI imaging technique can add a valuable option to CBCT in IGRT applications.

Comparative Study With New Accuracy Metrics for Target Volume Contouring in PET Image Guided Radiation Therapy

PubMed Central

Shepherd, T; Teras, M; Beichel, RR; Boellaard, R; Bruynooghe, M; Dicken, V; Gooding, MJ; Julyan, PJ; Lee, JA; Lefèvre, S; Mix, M; Naranjo, V; Wu, X; Zaidi, H; Zeng, Z; Minn, H

2017-01-01

The impact of positron emission tomography (PET) on radiation therapy is held back by poor methods of defining functional volumes of interest. Many new software tools are being proposed for contouring target volumes but the different approaches are not adequately compared and their accuracy is poorly evaluated due to the ill-definition of ground truth. This paper compares the largest cohort to date of established, emerging and proposed PET contouring methods, in terms of accuracy and variability. We emphasize spatial accuracy and present a new metric that addresses the lack of unique ground truth. Thirty methods are used at 13 different institutions to contour functional volumes of interest in clinical PET/CT and a custom-built PET phantom representing typical problems in image guided radiotherapy. Contouring methods are grouped according to algorithmic type, level of interactivity and how they exploit structural information in hybrid images. Experiments reveal benefits of high levels of user interaction, as well as simultaneous visualization of CT images and PET gradients to guide interactive procedures. Method-wise evaluation identifies the danger of over-automation and the value of prior knowledge built into an algorithm. PMID:22692898

SU-D-207A-04: Use of Gradient Echo Plural Contrast Imaging (GEPCI) in MR-Guided Radiation Therapy: A Feasibility Study Targeting Brain Treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cai, B; Rao, Y; Tsien, C

Purpose: To implement the Gradient Echo Plural Contrast Imaging(GEPCI) technique in MRI-simulation for radiation therapy and assess the feasibility of using GEPCI images with advanced inhomogeneity correction in MRI-guided radiotherapy for brain treatment. Methods: An optimized multigradient-echo GRE sequence (TR=50ms;TE1=4ms;delta-TE=4ms;flip angle=300,11 Echoes) was developed to generate both structural (T1w and T2*w) and functional MRIs (field and susceptibility maps) from a single acquisition. One healthy subject (Subject1) and one post-surgical brain cancer patient (Subject2) were scanned on a Philips Ingenia 1.5T MRI used for radiation therapy simulation. Another healthy subject (Subject3) was scanned on a 0.35T MRI-guided radiotherapy (MR-IGRT) system (ViewRay).more » A voxel spread function (VSF) was used to correct the B0 inhomogeneities caused by surgical cavities and edema for Subject2. GEPCI images and standard radiotherapy planning MRIs for this patient were compared focusing the delineation of radiotherapy target region. Results: GEPCI brain images were successfully derived from all three subjects with scan times of <7 minutes. The images derived for Subjects1&2 demonstrated that GEPCI can be applied and combined into radiotherapy MRI simulation. Despite low field, T1-weighted and R2* images were successfully reconstructed for Subject3 and were satisfactory for contour and target delineation. The R2* distribution of grey matter (center=12,FWHM=4.5) and white matter (center=14.6, FWHM=2) demonstrated the feasibility for tissue segmentation and quantification. The voxel spread function(VSF) corrected surgical site related inhomogeneities for Subject2. R2* and quantitative susceptibility map(QSM) images for Subject2 can be used to quantitatively assess the brain structure response to radiation over the treatment course. Conclusion: We implemented the GEPCI technique in MRI-simulation and in MR-IGRT system for radiation therapy. The images demonstrated that it is feasible to adopt this technique in radiotherapy for structural delineation. The preliminary data also enable the opportunity for quantitative assessment of radiation response of the target region and normal tissue.« less

Simple Thermal Environment Model (STEM) User's Guide

NASA Technical Reports Server (NTRS)

Justus, C.G.; Batts, G. W.; Anderson, B. J.; James, B. F.

2001-01-01

This report presents a Simple Thermal Environment Model (STEM) for determining appropriate engineering design values to specify the thermal environment of Earth-orbiting satellites. The thermal environment of a satellite, consists of three components: (1) direct solar radiation, (2) Earth-atmosphere reflected shortwave radiation, as characterized by Earth's albedo, and (3) Earth-atmosphere-emitted outgoing longwave radiation (OLR). This report, together with a companion "guidelines" report provides methodology and guidelines for selecting "design points" for thermal environment parameters for satellites and spacecraft systems. The methods and models reported here are outgrowths of Earth Radiation Budget Experiment (ERBE) satellite data analysis and thermal environment specifications discussed by Anderson and Smith (1994). In large part, this report is intended to update (and supersede) those results.

ICRP special radiation protection issues in interventional radiology, digital and cardiac imaging.

PubMed

Vano, E; Faulkner, K

2005-01-01

The International Commission on Radiological Protection (ICRP) has published two reports giving recommendations dealing with the avoidance of deterministic injuries in interventional radiology and the management of patient dose in digital radiology in 2001 and 2004, respectively. Another document, on radiation protection for cardiologists performing fluoroscopically guided procedures, will be produced during 2005. This paper highlights some of the topics of the published reports, their relevance to European legislation on medical exposures and the importance of radiation protection research in underpinning the ICRP task groups' work in to producing these documents. It is also anticipated that the results, obtained in the cardiology work package of the European research project, will be used in the new document on radiation protection for cardiologists.

TH-A-BRD-01: Radiation Biology for Radiation Therapy Physicists

DOE Office of Scientific and Technical Information (OSTI.GOV)

Orton, C; Borras, C; Carlson, D

Mechanisms by which radiation kills cells and ways cell damage can be repaired will be reviewed. The radiobiological parameters of dose, fractionation, delivery time, dose rate, and LET will be discussed. The linear-quadratic model for cell survival for high and low dose rate treatments and the effect of repopulation will be presented and discussed. The rationale for various radiotherapy techniques such as conventional fractionation, hyperfractionation, hypofractionation, and low and high dose rate brachytherapy, including permanent implants, will be presented. The radiobiological principles underlying radiation protection guidelines and the different radiation dosimetry terms used in radiation biology and in radiation protectionmore » will be reviewed. Human data on radiation induced cancer, including increases in the risk of second cancers following radiation therapy, as well as data on radiation induced tissue reactions, such as cardiovascular effects, for follow up times up to 20–40 years, published by ICRP, NCRP and BEIR Committees, will be examined. The latest risk estimates per unit dose will be presented. Their adoption in recent radiation protection standards and guidelines and their impact on patient and workers safety in radiotherapy will be discussed. Biologically-guided radiotherapy (BGRT) provides a systematic method to derive prescription doses that integrate patient-specific information about tumor and normal tissue biology. Treatment individualization based on patient-specific biology requires the identification of biological objective functions to facilitate the design and comparison of competing treatment modalities. Biological objectives provide a more direct approach to plan optimization instead of relying solely on dose-based surrogates and can incorporate factors that alter radiation response, such as DNA repair, tumor hypoxia, and relative biological effectiveness. We review concepts motivating biological objectives and provide examples of how they might be used to address clinically relevant problems. Underlying assumptions and limitations of existing models and their proper application will be discussed. This multidisciplinary educational session combines the fundamentals of radiobiology for radiation therapy and radiation protection with the practical application of biophysical models for treatment planning and evaluation. Learning Objectives: To understand fractionation in teletherapy and dose rate techniques in brachytherapy. To understand how the linear-quadratic models the effect of radiobiological parameters for radiotherapy. To understand the radiobiological basis of radiation protection standards applied to radiotherapy. To distinguish between stochastic effects and tissue reactions. To learn how to apply concepts of biological effective dose and RBE-weighted dose and to incorporate biological factors that alter radiation response. To discuss clinical strategies to increase therapeutic ratio, i.e., maximize local control while minimizing the risk of acute and late normal tissue effects.« less

Expanding the use of real-time electromagnetic tracking in radiation oncology.

PubMed

Shah, Amish P; Kupelian, Patrick A; Willoughby, Twyla R; Meeks, Sanford L

2011-11-15

In the past 10 years, techniques to improve radiotherapy delivery, such as intensity-modulated radiation therapy (IMRT), image-guided radiation therapy (IGRT) for both inter- and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery.

Expanding the use of real‐time electromagnetic tracking in radiation oncology

PubMed Central

Kupelian, Patrick A.; Willoughby, Twyla R.; Meeks, Sanford L.

2011-01-01

In the past 10 years, techniques to improve radiotherapy delivery, such as intensity‐modulated radiation therapy (IMRT), image‐guided radiation therapy (IGRT) for both inter‐ and intrafraction tumor localization, and hypofractionated delivery techniques such as stereotactic body radiation therapy (SBRT), have evolved tremendously. This review article focuses on only one part of that evolution, electromagnetic tracking in radiation therapy. Electromagnetic tracking is still a growing technology in radiation oncology and, as such, the clinical applications are limited, the expense is high, and the reimbursement is insufficient to cover these costs. At the same time, current experience with electromagnetic tracking applied to various clinical tumor sites indicates that the potential benefits of electromagnetic tracking could be significant for patients receiving radiation therapy. Daily use of these tracking systems is minimally invasive and delivers no additional ionizing radiation to the patient, and these systems can provide explicit tumor motion data. Although there are a number of technical and fiscal issues that need to be addressed, electromagnetic tracking systems are expected to play a continued role in improving the precision of radiation delivery. PACS number: 87.63.‐d PMID:22089017

Transport Test Problems for Hybrid Methods Development

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shaver, Mark W.; Miller, Erin A.; Wittman, Richard S.

2011-12-28

This report presents 9 test problems to guide testing and development of hybrid calculations for the ADVANTG code at ORNL. These test cases can be used for comparing different types of radiation transport calculations, as well as for guiding the development of variance reduction methods. Cases are drawn primarily from existing or previous calculations with a preference for cases which include experimental data, or otherwise have results with a high level of confidence, are non-sensitive, and represent problem sets of interest to NA-22.

Formation of ECR Plasma in a Dielectric Plasma Guide under Self-Excitation of a Standing Ion-Acoustic Wave

NASA Astrophysics Data System (ADS)

Balmashnov, A. A.; Kalashnikov, A. V.; Kalashnikov, V. V.; Stepina, S. P.; Umnov, A. M.

2018-01-01

The formation of a spatially localized plasma with a high brightness has been experimentally observed in a dielectric plasma guide under the electron cyclotron resonance discharge at the excitation of a standing ion-acoustic wave. The results obtained show the possibility of designing compact high-intensity radiation sources with a spectrum determined by the working gas or gas mixture type, high-intensity chemically active particle flow sources, and plasma thrusters for correcting orbits of light spacecraft.

High resolution PET breast imager with improved detection efficiency

DOEpatents

Majewski, Stanislaw

2010-06-08

A highly efficient PET breast imager for detecting lesions in the entire breast including those located close to the patient's chest wall. The breast imager includes a ring of imaging modules surrounding the imaged breast. Each imaging module includes a slant imaging light guide inserted between a gamma radiation sensor and a photodetector. The slant light guide permits the gamma radiation sensors to be placed in close proximity to the skin of the chest wall thereby extending the sensitive region of the imager to the base of the breast. Several types of photodetectors are proposed for use in the detector modules, with compact silicon photomultipliers as the preferred choice, due to its high compactness. The geometry of the detector heads and the arrangement of the detector ring significantly reduce dead regions thereby improving detection efficiency for lesions located close to the chest wall.

Clear-Sky Probability for the August 21, 2017, Total Solar Eclipse Using the NREL National Solar Radiation Database

DOE Office of Scientific and Technical Information (OSTI.GOV)

Habte, Aron M; Roberts, Billy J; Kutchenreiter, Mark C

The National Renewable Energy Laboratory (NREL) and collaborators have created a clear-sky probability analysis to help guide viewers of the August 21, 2017, total solar eclipse, the first continent-spanning eclipse in nearly 100 years in the United States. Using cloud and solar data from NREL's National Solar Radiation Database (NSRDB), the analysis provides cloudless sky probabilities specific to the date and time of the eclipse. Although this paper is not intended to be an eclipse weather forecast, the detailed maps can help guide eclipse enthusiasts to likely optimal viewing locations. Additionally, high-resolution data are presented for the centerline of themore » path of totality, representing the likelihood for cloudless skies and atmospheric clarity. The NSRDB provides industry, academia, and other stakeholders with high-resolution solar irradiance data to support feasibility analyses for photovoltaic and concentrating solar power generation projects.« less

Visitor’s Guide to Oliktok Point Atmospheric Radiation Measurement Climate Research Facility, North Slope of Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Desilets, Darin; Helsel, Fred M.; Bendure, Al O.

2016-04-01

The importance of Oliktok Point, Alaska, as a focal point for climate research in the Arctic continues to grow with the addition of a U.S. Department of Energy (DOE) Atmospheric Radiation Monitoring (ARM) Climate Research Facility Mobile Facility (AMF) and the expansion of infrastructure to support airborne measurements. The site hosts a suite of instruments for making multi-year, high-fidelity atmospheric measurements; serves as a base of operations for field campaigns; and contains the only Restricted Airspace and Warning Area in the U.S. Arctic, which enables the use of unmanned aircraft systems. The use of this site by climate researchers involvesmore » several considerations, including its remoteness, harsh climate, and location amid the North Slope oilfields. This guide is intended to help visitors to Oliktok Point navigate this unique physical and administrative environment, and thereby facilitate safe and productive operations.« less

Prototype of a single probe Compton camera for laparoscopic surgery

NASA Astrophysics Data System (ADS)

Koyama, A.; Nakamura, Y.; Shimazoe, K.; Takahashi, H.; Sakuma, I.

2017-02-01

Image-guided surgery (IGS) is performed using a real-time surgery navigation system with three-dimensional (3D) position tracking of surgical tools. IGS is fast becoming an important technology for high-precision laparoscopic surgeries, in which the field of view is limited. In particular, recent developments in intraoperative imaging using radioactive biomarkers may enable advanced IGS for supporting malignant tumor removal surgery. In this light, we develop a novel intraoperative probe with a Compton camera and a position tracking system for performing real-time radiation-guided surgery. A prototype probe consisting of Ce :Gd3 Al2 Ga3 O12 (GAGG) crystals and silicon photomultipliers was fabricated, and its reconstruction algorithm was optimized to enable real-time position tracking. The results demonstrated the visualization capability of the radiation source with ARM = ∼ 22.1 ° and the effectiveness of the proposed system.

Functional image-guided stereotactic body radiation therapy planning for patients with hepatocellular carcinoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsegmed, Uranchimeg; Kimura, Tomoki, E-mail: tkkimura@hiroshima-u.ac.jp; Nakashima, Takeo

The aim of the current planning study is to evaluate the ability of gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI)–guided stereotactic body radiation therapy (SBRT) planning by using intensity-modulated radiation therapy (IMRT) techniques in sparing the functional liver tissues during SBRT for hepatocellular carcinoma. In this study, 20 patients with hepatocellular carcinoma were enrolled. Functional liver tissues were defined according to quantitative liver-spleen contrast ratios ≥ 1.5 on a hepatobiliary phase scan. Functional images were fused with the planning computed tomography (CT) images; the following 2 SBRT plans were designed using a “step-and-shoot” static IMRT technique for each patient: (1) an anatomicalmore » SBRT plan optimization based on the total liver; and (2) a functional SBRT plan based on the functional liver. The total prescribed dose was 48 gray (Gy) in 4 fractions. Dosimetric parameters, including dose to 95% of the planning target volume (PTV D{sub 95%}), percentages of total and functional liver volumes, which received doses from 5 to 30 Gy (V5 to V30 and fV5 to fV30), and mean doses to total and functional liver (MLD and fMLD, respectively) of the 2 plans were compared. Compared with anatomical plans, functional image-guided SBRT plans reduced MLD (mean: plan A, 5.5 Gy; and plan F, 5.1 Gy; p < 0.0001) and fMLD (mean: plan A, 5.4 Gy; and plan F, 4.9 Gy; p < 0.0001), as well as V5 to V30 and fV5 to fV30. No differences were noted in PTV coverage and nonhepatic organs at risk (OARs) doses. In conclusion, EOB-MRI–guided SBRT planning using the IMRT technique may preserve functional liver tissues in patients with hepatocellular carcinoma (HCC).« less

Magnetic resonance imaging in precision radiation therapy for lung cancer

PubMed Central

Bainbridge, Hannah; Salem, Ahmed; Tijssen, Rob H. N.; Dubec, Michael; Wetscherek, Andreas; Van Es, Corinne; Belderbos, Jose; Faivre-Finn, Corinne

2017-01-01

Radiotherapy remains the cornerstone of curative treatment for inoperable locally advanced lung cancer, given concomitantly with platinum-based chemotherapy. With poor overall survival, research efforts continue to explore whether integration of advanced radiation techniques will assist safe treatment intensification with the potential for improving outcomes. One advance is the integration of magnetic resonance imaging (MRI) in the treatment pathway, providing anatomical and functional information with excellent soft tissue contrast without exposure of the patient to radiation. MRI may complement or improve the diagnostic staging accuracy of F-18 fluorodeoxyglucose position emission tomography and computerized tomography imaging, particularly in assessing local tumour invasion and is also effective for identification of nodal and distant metastatic disease. Incorporating anatomical MRI sequences into lung radiotherapy treatment planning is a novel application and may improve target volume and organs at risk delineation reproducibility. Furthermore, functional MRI may facilitate dose painting for heterogeneous target volumes and prediction of normal tissue toxicity to guide adaptive strategies. MRI sequences are rapidly developing and although the issue of intra-thoracic motion has historically hindered the quality of MRI due to the effect of motion, progress is being made in this field. Four-dimensional MRI has the potential to complement or supersede 4D CT and 4D F-18-FDG PET, by providing superior spatial resolution. A number of MR-guided radiotherapy delivery units are now available, combining a radiotherapy delivery machine (linear accelerator or cobalt-60 unit) with MRI at varying magnetic field strengths. This novel hybrid technology is evolving with many technical challenges to overcome. It is anticipated that the clinical benefits of MR-guided radiotherapy will be derived from the ability to adapt treatment on the fly for each fraction and in real-time, using ‘beam-on’ imaging. The lung tumour site group of the Atlantic MR-Linac consortium is working to generate a challenging MR-guided adaptive workflow for multi-institution treatment intensification trials in this patient group. PMID:29218271

Laser fiber-optic sensors for investigation of influences ultra weak cosmic radiation on the people.

NASA Astrophysics Data System (ADS)

Rzhavin, Yu.; Ignatiev, A.

The present work describes investigation of influences ultra weak cosmic radiation on the people, using laser fiber-optic bio sensors. Potential of the people measurements is made on the basis of two Mach-Zender interferometers. The measuring and reference channels of the device are made in the form of signal-mode light guides with w-profile, which retain the polarization of light [1].The effect of measurements leads to axial compression of the w-fiber guides in the measuring channel. The measured signal is recorded by the relative displasement of the structure of the interference pattern, which is caused by phase modulation of a coherent light wave [2] propagating in the measuring channel. The light guides in the measuring channel reeled up on a flat surface on a cirle by a diameter 1.8 meter. Length light guides made 100 meters. The people approached on distance of 0.3 meters to flat surfased. It has been demonstrated that the method based on calculation of the mutual correlation function of the output signals of the interferometers makes it possible to raise the signal/noise ratio of the device by eliminating irregular noise waves and reproducing an accurate shape of the measured signal.As the light source, we have used single-frequency semiconductor injection laser which external resonator was used and one of a resonator mirrors was the w-lightguide end with reflection structure deposited on it .The w-lightguidess had the cup-off wave length 1,1 um, the degree of retention of polarization 99 %. It has been demonstrated experimentally that the of the developed sensor, under constant level of the cosmic radiation measured bio potential of the people was defined from age, weight, and psychological of the condition. REFERENCES 1.Yu.I .Rzhavin et.al. Proceeding SPIE , vol. 2349 , pp.154-157 2. Yu.I.Rzhavin Proceeding SPIE , vol. 4827 , pp.253-257

Evaluation of the UF/NCI hybrid computational phantoms for use in organ dosimetry of pediatric patients undergoing fluoroscopically guided cardiac procedures

NASA Astrophysics Data System (ADS)

Marshall, Emily L.; Borrego, David; Tran, Trung; Fudge, James C.; Bolch, Wesley E.

2018-03-01

Epidemiologic data demonstrate that pediatric patients face a higher relative risk of radiation induced cancers than their adult counterparts at equivalent exposures. Infants and children with congenital heart defects are a critical patient population exposed to ionizing radiation during life-saving procedures. These patients will likely incur numerous procedures throughout their lifespan, each time increasing their cumulative radiation absorbed dose. As continued improvements in long-term prognosis of congenital heart defect patients is achieved, a better understanding of organ radiation dose following treatment becomes increasingly vital. Dosimetry of these patients can be accomplished using Monte Carlo radiation transport simulations, coupled with modern anatomical patient models. The aim of this study was to evaluate the performance of the University of Florida/National Cancer Institute (UF/NCI) pediatric hybrid computational phantom library for organ dose assessment of patients that have undergone fluoroscopically guided cardiac catheterizations. In this study, two types of simulations were modeled. A dose assessment was performed on 29 patient-specific voxel phantoms (taken as representing the patient’s true anatomy), height/weight-matched hybrid library phantoms, and age-matched reference phantoms. Two exposure studies were conducted for each phantom type. First, a parametric study was constructed by the attending pediatric interventional cardiologist at the University of Florida to model the range of parameters seen clinically. Second, four clinical cardiac procedures were simulated based upon internal logfiles captured by a Toshiba Infinix-i Cardiac Bi-Plane fluoroscopic unit. Performance of the phantom library was quantified by computing both the percent difference in individual organ doses, as well as the organ dose root mean square values for overall phantom assessment between the matched phantoms (UF/NCI library or reference) and the patient-specific phantoms. The UF/NCI hybrid phantoms performed at percent differences of between 15% and 30% for the parametric set of irradiation events. Among internal logfile reconstructed procedures, the UF/NCI hybrid phantoms performed with RMS organ dose values between 7% and 29%. Percent improvement in organ dosimetry via the use of hybrid library phantoms over the reference phantoms ranged from 6.6% to 93%. The use of a hybrid phantom library, Monte Carlo radiation transport methods, and clinical information on irradiation events provide a means for tracking organ dose in these radiosensitive patients undergoing fluoroscopically guided cardiac procedures. This work was supported by Advanced Laboratory for Radiation Dosimetry Studies, University of Florida, American Association of University Women, National Cancer Institute Grant 1F31 CA159464.

Exposure fluctuations of astronauts due to orientation

NASA Technical Reports Server (NTRS)

Wilson, John W.; Nealy, John E.; Wood, James S.; Qualls, Gary; Atwell, William; Shinn, Judy L.; Simonsen, Lisa C.

1993-01-01

The dose incurred in an anisotropic environment depends on the orientation of the astronaut's body relative to the direction of the radiation field. The fluctuations in exposure of specific organs due to astronaut orientation are found to be a factor of 2 or more in a typical space habitation module and typical space radiations. An approximation function is found that overestimates astronaut exposure in most cases studied and is recommended as a shield design guide for future space missions.

Lowering the Radiation Dose in Dental Offices.

PubMed

Radan, Elham

2017-04-01

While the use of dental imaging continues to evolve into more advanced modalities such as 3-D cone beam computed tomography, in addition to conventional 2-D imaging (intraoral, panoramic and cephalometric), the public concern for radiation safety is also increasing. This article is a guide for how to reduce patients’ exposure to the minimum with proper selection criteria (as needed only if it benefits the patient) and knowledge of effective doses, exposure parameters and proper collimation.

Fusion of Ultrasound Tissue-Typing Images with Multiparametric MRI for Image-guided Prostate Cancer Radiation Therapy

DTIC Science & Technology

2014-10-01

work under the guidance of an outstanding mentor team at Emory Winship Cancer Institute. I took three courses ( Medical Health Physics, Radiation...and Late Normal-Tissue Toxicity in Breast- Cancer Radiotherapy”, Medical Physics, 40(6):379, 2013. 5. Yang X, Liu T, Curran W and Torres M...Analysis for Normal-tissue Toxicity: A Prospective Ultrasound Study of Acute Toxicity in Breast- Cancer Radiotherapy", Medical Physics 41 (6), 482-482

A quantitative analysis of craniopharyngioma cyst expansion during and after radiation therapy and surgical implications.

PubMed

Lamiman, Kelly; Wong, Kenneth K; Tamrazi, Benita; Nosrati, Jason D; Olch, Arthur; Chang, Eric L; Kiehna, Erin N

2016-12-01

OBJECTIVE When complete resection of craniopharyngioma is not achievable or the sequelae are prohibitive, limited surgery and radiation therapy have demonstrated excellent local disease control while minimizing treatment-related sequelae. When residual tissue exists, there is a propensity for further cyst development and expansion during and after radiation therapy. This can result in obstructive hydrocephalus, visual changes, and/or clinical decline. The authors present a quantitative analysis of cyst expansion during and after radiotherapy and examine how it affected subsequent management. METHODS The authors performed an institutional review board-approved retrospective study of patients with histologically confirmed craniopharyngioma treated between 2000 and 2015 with surgery and intensity-modulated radiation therapy (IMRT) at a single institution. Volumetric measurements of cyst contours were generated by radiation oncology treatment planning software postoperatively, during IMRT, and up to 12 months after IMRT. Patient, tumor, and treatment-related variables were collected until the last known follow-up and were analyzed. RESULTS Twenty-seven patients underwent surgery and IMRT. The median total radiation dose was 54 Gy. Of the 27 patients, 11 patients (40.7%) demonstrated cyst expansions within 1 year of IMRT. Of note, all tumors with cyst expansion were radiographically Puget Grade 2. Maximal cyst expansion peaked at 4.27 months following radiation therapy, with a median volume growth of 4.1 cm 3 (mean 9.61 cm 3 ) above the postoperative cyst volume. Eight patients experienced spontaneous cyst regression without therapeutic intervention. Three patients experienced MRI-confirmed cyst enlargement during IMRT, all of whom required adaptive planning to ensure adequate coverage of the entire tumor volume. Two of these 3 patients required ventriculoperitoneal shunt placement and additional intervention. One underwent additional resection, and the other had placement of an intracystic catheter for aspiration and delivery of intracystic interferon within 12 months of completing IMRT. All 3 patients now have stable disease. CONCLUSIONS Craniopharyngioma cyst expansion occurred in approximately 40% of the patients during or after radiotherapy. In the majority of patients, cyst expansion was a self-limiting process and did not confer a worse outcome. During radiotherapy, cyst expansion may be apparent on image-guided radiation therapy. Adaptive IMRT planning may be required to ensure that the intended IMRT dose covers the entire tumor and cyst volume. The sequelae of cyst expansion include progressive hydrocephalus, which may be treated with a shunt. For patients with solitary cyst expansion, cyst aspiration and/or intracystic interferon may result in disease control.

[Powdered infant formulae preparation guide for hospitals based on Hazard Analysis and Critical Control Points (HACCP) principles].

PubMed

Vargas-Leguás, H; Rodríguez Garrido, V; Lorite Cuenca, R; Pérez-Portabella, C; Redecillas Ferreiro, S; Campins Martí, M

2009-06-01

This guide for the preparation of powdered infant formulae in hospital environments is a collaborative work between several hospital services and is based on national and European regulations, international experts meetings and the recommendations of scientific societies. This guide also uses the Hazard Analysis and Critical Control Point principles proposed by Codex Alimentarius and emphasises effective verifying measures, microbiological controls of the process and the corrective actions when monitoring indicates that a critical control point is not under control. It is a dynamic guide and specifies the evaluation procedures that allow it to be constantly adapted.

Air traffic control system baseline methodology guide.

DOT National Transportation Integrated Search

1999-06-01

The Air Traffic Control System Baseline Methodology Guide serves as a reference in the design and conduct of baseline studies. : Engineering research psychologists are the intended audience for the Methodology Guide, which focuses primarily on techni...

Tissue feature-based intra-fractional motion tracking for stereoscopic x-ray image guided radiotherapy

NASA Astrophysics Data System (ADS)

Xie, Yaoqin; Xing, Lei; Gu, Jia; Liu, Wu

2013-06-01

Real-time knowledge of tumor position during radiation therapy is essential to overcome the adverse effect of intra-fractional organ motion. The goal of this work is to develop a tumor tracking strategy by effectively utilizing the inherent image features of stereoscopic x-ray images acquired during dose delivery. In stereoscopic x-ray image guided radiation delivery, two orthogonal x-ray images are acquired either simultaneously or sequentially. The essence of markerless tumor tracking is the reliable identification of inherent points with distinct tissue features on each projection image and their association between two images. The identification of the feature points on a planar x-ray image is realized by searching for points with high intensity gradient. The feature points are associated by using the scale invariance features transform descriptor. The performance of the proposed technique is evaluated by using images of a motion phantom and four archived clinical cases acquired using either a CyberKnife equipped with a stereoscopic x-ray imaging system, or a LINAC equipped with an onboard kV imager and an electronic portal imaging device. In the phantom study, the results obtained using the proposed method agree with the measurements to within 2 mm in all three directions. In the clinical study, the mean error is 0.48 ± 0.46 mm for four patient data with 144 sequential images. In this work, a tissue feature-based tracking method for stereoscopic x-ray image guided radiation therapy is developed. The technique avoids the invasive procedure of fiducial implantation and may greatly facilitate the clinical workflow.

Assessment of three-dimensional setup errors in image-guided pelvic radiotherapy for uterine and cervical cancer using kilovoltage cone-beam computed tomography and its effect on planning target volume margins.

PubMed

Patni, Nidhi; Burela, Nagarjuna; Pasricha, Rajesh; Goyal, Jaishree; Soni, Tej Prakash; Kumar, T Senthil; Natarajan, T

2017-01-01

To achieve the best possible therapeutic ratio using high-precision techniques (image-guided radiation therapy/volumetric modulated arc therapy [IGRT/VMAT]) of external beam radiation therapy in cases of carcinoma cervix using kilovoltage cone-beam computed tomography (kV-CBCT). One hundred and five patients of gynecological malignancies who were treated with IGRT (IGRT/VMAT) were included in the study. CBCT was done once a week for intensity-modulated radiation therapy and daily in IGRT/VMAT. These images were registered with the planning CT scan images and translational errors were applied and recorded. In all, 2078 CBCT images were studied. The margins of planning target volume were calculated from the variations in the setup. The setup variation was 5.8, 10.3, and 5.6 mm in anteroposterior, superoinferior, and mediolateral direction. This allowed adequate dose delivery to the clinical target volume and the sparing of organ at risks. Daily kV-CBCT is a satisfactory method of accurate patient positioning in treating gynecological cancers with high-precision techniques. This resulted in avoiding geographic miss.

Use of bremsstrahlung radiation to identify hidden weak β- sources: feasibility and possible use in radio-guided surgery

NASA Astrophysics Data System (ADS)

Carlotti, D.; Collamati, F.; Faccini, R.; Fresch, P.; Iacoangeli, F.; Mancini-Terracciano, C.; Marafini, M.; Mirabelli, R.; Recchia, L.; Russomando, A.; Solfaroli Camillocci, E.; Toppi, M.; Traini, G.; Bocci, V.

2017-11-01

The recent interest in β^- radionuclides for radio-guided surgery derives from the feature of the β radiation to release energy in few millimeters of tissue. Such feature can be used to locate residual tumors with a probe located in its immediate vicinity, determining the resection margins with an accuracy of millimeters. The drawback of this technique is that it does not allow to identify tumors hidden in more than few mm of tissue. Conversely, the bremsstrahlung X-rays emitted by the interaction of the β- radiation with the nuclei of the tissue are relatively penetrating. To complement the β- probes, we have therefore developed a detector based on cadmium telluride, an X-ray detector with a high quantum efficiency working at room temperature. We measured the secondary emission of bremsstrahlung photons in a target of Polymethylmethacrylate (PMMA) with a density similar to living tissue. The results show that this device allows to detect a 1 ml residual or lymph-node with an activity of 1 kBq hidden under a layer of 10 mm of PMMA with a 3:1 signal to noise, i.e. with a five sigma discrimination in less than 5 s.

Using 3D dosimetry to quantify the Electron Return Effect (ERE) for MR-image-guided radiation therapy (MR-IGRT) applications

NASA Astrophysics Data System (ADS)

Lee, Hannah J.; Choi, Gye Won; Alqathami, Mamdooh; Kadbi, Mo; Ibbott, Geoffrey

2017-05-01

Image-guided radiation therapy (IGRT) using computed tomography (CT), cone-beam CT, MV on-board imager (OBI), and kV OBI systems have allowed for more accurate patient positioning prior to each treatment fraction. While these imaging modalities provide excellent bony anatomy image quality, MRI surpasses them in soft tissue image contrast for better visualization and tracking of soft tissue tumors with no additional radiation dose to the patient. A pre-clinical integrated 1.5 T magnetic resonance imaging and 7 MV linear accelerator system (MR-linac) allows for real-time tracking of soft tissues and adaptive treatment planning prior to each treatment fraction. However, due to the presence of a strong magnetic field from the MR component, there is a three dimensional (3D) change in dose deposited by the secondary electrons. Especially at nonhomogeneous anatomical sites with tissues of very different densities, dose enhancements and reductions can occur due to the Lorentz force influencing the trajectories of secondary electrons. These dose changes at tissue interfaces are called the electron return effect or ERE. This study investigated the ERE using 3D dosimeters.

Image-guided interventional therapy for cancer with radiotherapeutic nanoparticles✩

PubMed Central

Phillips, William T.; Bao, Ande; Brenner, Andrew J.; Goins, Beth A.

2015-01-01

One of the major limitations of current cancer therapy is the inability to deliver tumoricidal agents throughout the entire tumor mass using traditional intravenous administration. Nanoparticles carrying beta-emitting therapeutic radionuclides that are delivered using advanced image-guidance have significant potential to improve solid tumor therapy. The use of image-guidance in combination with nanoparticle carriers can improve the delivery of localized radiation to tumors. Nanoparticles labeled with certain beta-emitting radionuclides are intrinsically theranostic agents that can provide information regarding distribution and regional dosimetry within the tumor and the body. Image-guided thermal therapy results in increased uptake of intravenous nanoparticles within tumors, improving therapy. In addition, nanoparticles are ideal carriers for direct intratumoral infusion of beta-emitting radionuclides by convection enhanced delivery, permitting the delivery of localized therapeutic radiation without the requirement of the radionuclide exiting from the nanoparticle. With this approach, very high doses of radiation can be delivered to solid tumors while sparing normal organs. Recent technological developments in image-guidance, convection enhanced delivery and newly developed nanoparticles carrying beta-emitting radionuclides will be reviewed. Examples will be shown describing how this new approach has promise for the treatment of brain, head and neck, and other types of solid tumors. PMID:25016083

Stereotactic CO2 laser therapy for hydrocephalus

NASA Astrophysics Data System (ADS)

Kozodoy-Pins, Rebecca L.; Harrington, James A.; Zazanis, George A.; Nosko, Michael G.; Lehman, Richard M.

1994-05-01

A new fiber-optic delivery system for CO2 radiation has been used to successfully treat non-communicating hydrocephalus. This system consists of a hollow sapphire waveguide employed in the lumen of a stereotactically-guided neuroendoscope. CO2 gas flows through the bore of the hollow waveguide, creating a path for the laser beam through the cerebrospinal fluid (CSF). This delivery system has the advantages of both visualization and guided CO2 laser radiation without the same 4.3 mm diameter scope. Several patients with hydrocephalus were treated with this new system. The laser was used to create a passage in the floor of the ventricle to allow the flow of CSF from the ventricles to the sub-arachnoid space. Initial postoperative results demonstrated a relief of the clinical symptoms. Long-term results will indicate if this type of therapy will be superior to the use of implanted silicone shunts. Since CO2 laser radiation at 10.6 micrometers is strongly absorbed by the water in tissue and CSF, damage to tissue surrounding the lesion with each laser pulse is limited. The accuracy and safety of this technique may prove it to be an advantageous therapy for obstructive hydrocephalus.

Two-and-a-half-year clinical experience with the world's first magnetic resonance image guided radiation therapy system.

PubMed

Fischer-Valuck, Benjamin W; Henke, Lauren; Green, Olga; Kashani, Rojano; Acharya, Sahaja; Bradley, Jeffrey D; Robinson, Clifford G; Thomas, Maria; Zoberi, Imran; Thorstad, Wade; Gay, Hiram; Huang, Jiayi; Roach, Michael; Rodriguez, Vivian; Santanam, Lakshmi; Li, Harold; Li, Hua; Contreras, Jessika; Mazur, Thomas; Hallahan, Dennis; Olsen, Jeffrey R; Parikh, Parag; Mutic, Sasa; Michalski, Jeff

2017-01-01

Magnetic resonance image guided radiation therapy (MR-IGRT) has been used at our institution since 2014. We report on more than 2 years of clinical experience in treating patients with the world's first MR-IGRT system. A clinical service was opened for MR-IGRT in January 2014 with an MR-IGRT system consisting of a split 0.35T magnetic resonance scanner that straddles a ring gantry with 3 multileaf collimator-equipped 60 Co heads. The service was expanded to include online adaptive radiation therapy (ART) MR-IGRT and cine gating after 6 and 9 months, respectively. Patients selected for MR-IGRT were enrolled in a prospective registry between January 2014 and June 2016. Patients were treated with a variety of radiation therapy techniques including intensity modulated radiation therapy and stereotactic body radiation therapy (SBRT). When applicable, online ART was performed and gating on sagittal 2-dimensional cine MR was used. The charts of patients treated with MR-IGRT were reviewed to report on the clinical and treatment characteristics of the initial patients who were treated with this novel technique. A total of 316 patients have been treated with the MR-IGRT system, which has been integrated into a high-volume clinic. The cases were most commonly selected for improved soft tissue visualization, ART, and cine gating. Seventy-six patients were treated with 3-dimensional conformal radiation therapy, 146 patients with intensity modulated radiation therapy, and 94 patients with SBRT. The most commonly treated disease sites were the abdomen (28%), breast (26%), pelvis (22%), thorax (19%), and head and neck (5%). Sixty-seven patients were treated with online ART over a total of 244 adapted fractions. Cine treatment gating was used for a total of 81 patients. MR-IGRT has been successfully implemented in a high-volume radiation clinic and provides unique advantages in the treatment of a variety of malignancies. Additional clinical trials are in development to formally evaluate MR-IGRT in the treatment of multiple disease sites with techniques such as SBRT and ART.

KSC-2012-4560

NASA Image and Video Library

2012-08-22

CAPE CANAVERAL, Fla. – Workers help guide the United Launch Alliance Atlas V rocket with the Radiation Belt Storm Probes, or RBSP, spacecraft aboard as it moves to the launch pad at Space Launch Complex 41 at Cape Canaveral Air Force Station. NASA’s RBSP mission will help researchers understand the sun’s influence on Earth and near-Earth space by studying the Earth’s radiation belts on various scales of space and time. RBSP will begin its mission of exploration of Earth’s Van Allen radiation belts and the extremes of space weather after its launch aboard an Atlas V rocket. Launch is targeted for Aug. 24. Photo credit: NASA/Kim Shiflett

KSC-2012-4558

NASA Image and Video Library

2012-08-22

CAPE CANAVERAL, Fla. – Workers help guide the United Launch Alliance Atlas V rocket with the Radiation Belt Storm Probes, or RBSP, spacecraft aboard as it moves to the launch pad at Space Launch Complex 41 at Cape Canaveral Air Force Station. NASA’s RBSP mission will help researchers understand the sun’s influence on Earth and near-Earth space by studying the Earth’s radiation belts on various scales of space and time. RBSP will begin its mission of exploration of Earth’s Van Allen radiation belts and the extremes of space weather after its launch aboard an Atlas V rocket. Launch is targeted for Aug. 24. Photo credit: NASA/Kim Shiflett

KSC-2012-4559

NASA Image and Video Library

2012-08-22

CAPE CANAVERAL, Fla. – Workers help guide the United Launch Alliance Atlas V rocket with the Radiation Belt Storm Probes, or RBSP, spacecraft aboard as it moves to the launch pad at Space Launch Complex 41 at Cape Canaveral Air Force Station. NASA’s RBSP mission will help researchers understand the sun’s influence on Earth and near-Earth space by studying the Earth’s radiation belts on various scales of space and time. RBSP will begin its mission of exploration of Earth’s Van Allen radiation belts and the extremes of space weather after its launch aboard an Atlas V rocket. Launch is targeted for Aug. 24. Photo credit: NASA/Kim Shiflett

Observational and Modeling Studies of Clouds and the Hydrological Cycle

NASA Technical Reports Server (NTRS)

Somerville, Richard C. J.

1997-01-01

Our approach involved validating parameterizations directly against measurements from field programs, and using this validation to tune existing parameterizations and to guide the development of new ones. We have used a single-column model (SCM) to make the link between observations and parameterizations of clouds, including explicit cloud microphysics (e.g., prognostic cloud liquid water used to determine cloud radiative properties). Surface and satellite radiation measurements were used to provide an initial evaluation of the performance of the different parameterizations. The results of this evaluation will then used to develop improved cloud and cloud-radiation schemes, which were tested in GCM experiments.

Evaluation of image-guided helical tomotherapy for the retreatment of spinal metastasis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mahan, Stephen L.; Ramsey, Chester R.; Scaperoth, Daniel D.

Introduction: Patients with vertebral metastasis that receive radiation therapy are typically treated to the spinal cord tolerance dose. As such, it is difficult to successfully deliver a second course of radiation therapy for patients with overlapping treatment volumes. In this study, an image-guided helical tomotherapy system was evaluated for the retreatment of previously irradiated vertebral metastasis. Methods and Materials: Helical tomotherapy dose gradients and maximum cord doses were measured in a cylindrical phantom for geometric test cases with separations between the planning target volume (PTV) and the spinal cord organ at risk (OAR) of 2 mm, 4 mm, 6 mm,more » 8 mm, and 10 mm. Megavoltage computed tomography (CT) images were examined for their ability to localize spinal anatomy for positioning purposes by repeat imaging of the cervical spine in an anthropomorphic phantom. In addition to the phantom studies, 8 patients with cord compressions that had received previous radiation therapy were retreated to a mean dose of 28 Gy using conventional fractionation. Results and Discussion: Megavoltage CT images were capable of positioning an anthropomorphic phantom to within {+-}1.2 mm (2{sigma}) superior-inferiorly and within {+-}0.6 mm (2{sigma}) anterior-posteriorly and laterally. Dose gradients of 10% per mm were measured in phantom while PTV uniformity indices of less than 11% were maintained. The calculated maximum cord dose was 25% of the prescribed dose for a 10-mm PTV-to-OAR separation and 71% of the prescribed dose for a PTV-to-OAR separation of 2 mm. Eight patients total have been treated without radiation-induced myelopathy or any other adverse effects from treatment. Conclusions: A technique has been evaluated for the retreatment of vertebral metastasis using image-guided helical tomotherapy. Phantom and patient studies indicated that a tomotherapy system is capable of delivering dose gradients of 10% per mm and positioning the patient within 1.2 mm without the use of special stereotactic immobilization.« less

Duty to Inform and Informed Consent in Diagnostic Radiology: How Ethics and Law can Better Guide Practice.

PubMed

Doudenkova, Victoria; Bélisle Pipon, Jean-Christophe

2016-03-01

Although there is consensus on the fact that ionizing radiation used in radiological examinations can affect health, the stochastic (random) nature of risk makes it difficult to anticipate and assess specific health implications for patients. The issue of radiation protection is peculiar as any dosage received in life is cumulative, the sensitivity to radiation is highly variable from one person to another, and between 20 % and 50 % of radiological examinations appear not to be necessary. In this context, one might reasonably assume that information and patient consent would play an important role in regulating radiological practice. However, there is to date no clear consensus regarding the nature and content of-or even need for-consent by patients exposed to ionizing radiation. While law and ethics support the same principles for respecting the dignity of the person (inviolability and integrity), in the context of radiology practice, they do not provide a consistent message to guide clinical decision-making. This article analyzes the issue of healthcare professionals' duty to inform and obtain patient consent for radiological examinations. Considering that both law and ethics have as one of their aims to protect vulnerable populations, it is important that they begin to give greater attention to issues raised by the use of ionizing radiation in medicine. While the situation in Canada serves as a backdrop for a reflective analysis of the problem, the conclusions are pertinent for professional practice in other jurisdictions because the principles underlying health law and jurisprudence are fairly general.

Examples of Radiation-Emitting Products

MedlinePlus

... Ultrasonography • Doppler ultrasound • Color doppler ultrasound • Hyperthermia • Diathermy/physical therapy • Bone healing • Lithotripsy • Phacoemulsifier • Needle guide • Bone density measuring • Geriatric bath (ultrasound) • Hearing aid • Many scientific uses • Nondestructive ...

Sonography-guided hydrostatic reduction of ileocolic intussusception in children: analysis of failure and success in consecutive patients presenting timely to the hospital.

PubMed

Menke, Jan; Kahl, Fritz

2015-03-01

In children with ileocolic intussusception sonography is increasingly being used for diagnosis, whereas fluoroscopy is frequently used for guiding non-invasive reduction. This study assessed the success rate of radiation-free sonography-guided hydrostatic reduction in children with ileocolic intussusception, using novel well-defined success rate indices. All children were evaluated who presented from 2005 to 2013 to the local university hospital with ileocolic intussusception. The patients were treated with sonography-guided hydrostatic reduction unless primary surgery was clinically indicated. The according success rate was determined by indices of Bekdash et al. They represent the ratio of persistently successful non-surgical reductions versus four different denominators, depending on including/excluding cases with primary surgery and including/excluding cases requiring bowel resection/intervention. Fifty-six consecutive patients were included (age, 3 months to 7.8 years). About 80% of the patients presented until 24 h and 20% until 48 h after the onset of symptoms. Seven patients underwent primary surgery, with bowel resection required in three cases. Hydrostatic reduction was attempted in 49 patients, being permanently successful in 41 cases (selective reduction rate 41/49 = 83.7%; crude reduction rate 41/56 = 73.2%). The remaining eight patients underwent secondary surgery, with just two patients not requiring surgical bowel resection/intervention (corrected selective reduction rate 41/43 = 95.3%). The composite reduction rate was 87.2% (successful/feasible reductions, 41/47). Radiation-free sonography-guided hydrostatic reduction has a good success rate in children with ileocolic intussusception. It may be particularly valuable in centers that are already experienced with using sonography for the diagnosis.

OCCUPATIONAL RADIATION DOSES TO OPERATORS PERFORMING FLUOROSCOPICALLY-GUIDED PROCEDURES

PubMed Central

Kim, Kwang Pyo; Miller, Donald L.; de Gonzalez, Amy Berrington; Balter, Stephen; Kleinerman, Ruth A.; Ostroumova, Evgenia; Simon, Steven L.; Linet, Martha S.

2012-01-01

In the past 30 years, the numbers and types of fluoroscopically-guided (FG) procedures have increased dramatically. The objective of the present study is to provide estimated radiation doses to physician specialists, other than cardiologists, who perform FG procedures. We searched Medline to identify English-language journal articles reporting radiation exposures to these physicians. We then identified several primarily therapeutic FG procedures that met specific criteria: well-defined procedures for which there were at least five published reports of estimated radiation doses to the operator, procedures performed frequently in current medical practice, and inclusion of physicians from multiple medical specialties. These procedures were percutaneous nephrolithotomy (PCNL), vertebroplasty, orthopedic extremity nailing for treatment of fractures, biliary tract procedures, transjugular intrahepatic portosystemic shunt creation (TIPS), head/neck endovascular therapeutic procedures, and endoscopic retrograde cholangiopancreatography (ERCP). We abstracted radiation doses and other associated data, and estimated effective dose to operators. Operators received estimated doses per patient procedure equivalent to doses received by interventional cardiologists. The estimated effective dose per case ranged from 1.7 – 56μSv for PCNL, 0.1 – 101 μSv for vertebroplasty, 2.5 – 88μSv for orthopedic extremity nailing, 2.0 – 46μSv for biliary tract procedures, 2.5 – 74μSv for TIPS, 1.8 – 53μSv for head/neck endovascular therapeutic procedures, and 0.2 – 49μSv for ERCP. Overall, mean operator radiation dose per case measured over personal protective devices at different anatomic sites on the head and body ranged from 19 – 800 (median = 113) μSv at eye level, 6 – 1180 (median = 75)μSv at the neck, and 2 – 1600 (median = 302) μSv at the trunk. Operators’ hands often received greater doses than the eyes, neck or trunk. Large variations in operator doses suggest that optimizing procedure protocols and proper use of protective devices and shields might reduce occupational radiation dose substantially. PMID:22647920

Radiation-Induced Skin Injuries to Patients: What the Interventional Radiologist Needs to Know.

PubMed

Jaschke, Werner; Schmuth, Matthias; Trianni, Annalisa; Bartal, Gabriel

2017-08-01

For a long time, radiation-induced skin injuries were only encountered in patients undergoing radiation therapy. In diagnostic radiology, radiation exposures of patients causing skin injuries were extremely rare. The introduction of fast multislice CT scanners and fluoroscopically guided interventions (FGI) changed the situation. Both methods carry the risk of excessive high doses to the skin of patients resulting in skin injuries. In the early nineties, several reports of epilation and skin injuries following CT brain perfusion studies were published. During the same time, several papers reported skin injuries following FGI, especially after percutaneous coronary interventions and neuroembolisations. Thus, CT and FGI are of major concern regarding radiation safety since both methods can apply doses to patients exceeding 5 Gy (National Council on Radiation Protection and Measurements threshold for substantial radiation dose level). This paper reviews the problem of skin injuries observed after FGI. Also, some practical advices are given how to effectively avoid skin injuries. In addition, guidelines are discussed how to deal with patients who were exposed to a potentially dangerous radiation skin dose during medically justified interventional procedures.

CT-guided transgluteal biopsy for systematic sampling of the prostate in patients without rectal access: a 13-year single-center experience.

PubMed

Olson, Michael C; Atwell, Thomas D; Mynderse, Lance A; King, Bernard F; Welch, Timothy; Goenka, Ajit H

2017-08-01

The purpose of our study was to examine the safety and diagnostic utility of transgluteal CT-guided prostate biopsy for prostate sampling in patients without rectal access. Seventy-three biopsies were performed in 65 patients over a 13-year period (2002-2015). Mean prostate-specific antigen (PSA) at biopsy was 7.8 ng/mL (range 0.37-31.5). Electronic medical records were reviewed for procedural details and complications. Mean PSA and number of cores in malignant and benign cohorts were compared with Student's t test. Technical success rate was 97.3% (71/73; mean cores 8, range 3-28). Of these, 43.6% (31/71) yielded malignancy (mean Gleason score 7, range 6-10) and 56.3% (40/71) yielded benign tissue. The only complication was an asymptomatic periprostatic hematoma (1/73; 1.4%). In 14 patients who underwent surgery, Gleason scores were concordant in 71.4% (10/14) and discordant in 28.6% (4/14; Gleason 6 on biopsy but Gleason 7 on surgical specimen). Mean effective radiation dose was 18.5 mSv (median 15.0, range 4.4-86.2). There was no significant difference in either mean PSA (p = 0.06) or number of core specimens (p = 0.33) between malignant and benign cohorts. CT-guided transgluteal prostate biopsy is highly safe and reliable for the detection of prostate cancer in men without rectal access. • Prostate cancer detection in men without rectal access is challenging. • CT-guided transgluteal prostate biopsy is safe and effective in these patients. • CT-guided biopsy may be particularly effective in diagnosing high-grade prostate cancer. • Unilateral CT-guided biopsy may be effective in patients with focal lesions. • The radiation exposure with this technique is acceptable.

Engine Performance (Section C: Emission Control Systems). Auto Mechanics Curriculum Guide. Module 3. Instructor's Guide.

ERIC Educational Resources Information Center

Rains, Larry

This engine performance (emission control systems) module is one of a series of competency-based modules in the Missouri Auto Mechanics Curriculum Guide. Topics of this module's five units are: positive crankcase ventilation (PCV) and evaporative emission control systems; exhaust gas recirculation (EGR); air injection and catalytic converters;…

Influence of (11)C-choline PET/CT on radiotherapy planning in prostate cancer.

PubMed

López, Escarlata; Lazo, Antonio; Gutiérrez, Antonio; Arregui, Gregorio; Núñez, Isabel; Sacchetti, Antonio

2015-01-01

To evaluate the influence of (11)C-choline PET/CT on radiotherapy planning in prostate cancer patients. Precise information on the extension of prostate cancer is crucial for the choice of an appropriate therapeutic strategy. (11)C-choline positron emission tomography ((11)C-choline PET/CT) has two roles in radiation oncology (RT): (1) patient selection for treatment and (2) target volume selection and delineation. In conjunction with high-accuracy techniques, it might offer an opportunity of dose escalation and better tumour control while sparing healthy tissues. We carried out a retrospective study in order to analyse RT planning modification based on (11)C-choline PET/CT in 16 prostate cancer patients. Patients were treated with hypofractionated step-and-shoot Intensity Modulated Radiotherapy (IMRT), or Volumetric Modulated Arc Therapy (VMAT), and a daily cone-beam CT for Image Guided Radiation Therapy (IGRT). All patients underwent a (11)C-choline-PET/CT scan prior to radiotherapy. In 37.5% of cases, a re-delineation and new dose prescription occurred. Data show good preliminary clinical results in terms of biochemical control and toxicity. No gastrointestinal (GI)/genitourinary (GU) grade III toxicities were observed after a median follow-up of 9.5 months. In our experience, concerning the treatment of prostate cancer (PCa), (11)C-choline PET/CT may be helpful in radiotherapy planning, either for dose escalation or exclusion of selected sites.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elnahal, Shereef M., E-mail: selnaha1@jhmi.edu; Blackford, Amanda; Smith, Koren

Purpose: To describe radiation therapy cases during which voluntary incident reporting occurred; and identify patient- or treatment-specific factors that place patients at higher risk for incidents. Methods and Materials: We used our institution's incident learning system to build a database of patients with incident reports filed between January 2011 and December 2013. Patient- and treatment-specific data were reviewed for all patients with reported incidents, which were classified by step in the process and root cause. A control group of patients without events was generated for comparison. Summary statistics, likelihood ratios, and mixed-effect logistic regression models were used for group comparisons. Results:more » The incident and control groups comprised 794 and 499 patients, respectively. Common root causes included documentation errors (26.5%), communication (22.5%), technical treatment planning (37.5%), and technical treatment delivery (13.5%). Incidents were more frequently reported in minors (age <18 years) than in adult patients (37.7% vs 0.4%, P<.001). Patients with head and neck (16% vs 8%, P<.001) and breast (20% vs 15%, P=.03) primaries more frequently had incidents, whereas brain (18% vs 24%, P=.008) primaries were less frequent. Larger tumors (17% vs 10% had T4 lesions, P=.02), and cases on protocol (9% vs 5%, P=.005) or with intensity modulated radiation therapy/image guided intensity modulated radiation therapy (52% vs 43%, P=.001) were more likely to have incidents. Conclusions: We found several treatment- and patient-specific variables associated with incidents. These factors should be considered by treatment teams at the time of peer review to identify patients at higher risk. Larger datasets are required to recommend changes in care process standards, to minimize safety risks.« less

Reirradiation of Head and Neck Cancers With Intensity Modulated Radiation Therapy: Outcomes and Analyses

DOE Office of Scientific and Technical Information (OSTI.GOV)

Takiar, Vinita; Garden, Adam S.; Ma, Dominic

Purpose: To review our 15-year institutional experience using intensity modulated radiation therapy (IMRT) to reirradiate patients with head and neck squamous cell carcinomas (HNSCC) and identify predictors of outcomes and toxicity. Methods and Materials: We retrospectively reviewed the records of 227 patients who received head and neck reirradiation using IMRT from 1999 to 2014. Patients treated with noncurative intent were excluded. Radiation-related acute and late toxicities were recorded. Prognostic variables included performance status, disease site, disease-free interval, chemotherapy, and RT dose and volume. Correlative analyses were performed separately for surgery and nonsurgery patients. Results: Two hundred six patients (91%) were retreatedmore » with curative intent, and 173 had HNSCC histology; 104 (50%) underwent salvage resection, and 135 (66%) received chemotherapy. Median follow-up after reirradiation was 24.7 months. Clinical outcomes were worse for HNSCC patients, with 5-year locoregional control, progression-free survival, and overall survival rates of 53%, 22%, and 32%, respectively, compared with 74%, 59%, and 79%, respectively, for non-HNSCC patients. On multivariate analysis, concurrent chemotherapy and retreatment site were associated with tumor control, whereas performance status was associated with survival. Favorable prognostic factors specific to surgery patients were neck retreatment and lack of extracapsular extension, whereas for nonsurgery patients, these were a nasopharynx subsite and complete response to induction chemotherapy. Actuarial rates of grade ≥3 toxicity were 32% at 2 years and 48% at 5 years, with dysphagia or odynophagia being most common. Increased grade ≥3 toxicity was associated with retreatment volume >50 cm{sup 3} and concurrent chemotherapy. Conclusions: Reirradiation with IMRT either definitively or after salvage surgery can produce promising local control and survival in selected patients with head and neck cancers. Treatment-related toxicity remains significant. Prognostic factors are emerging to guide multidisciplinary treatment approaches and clinical trial design.« less

Microwave metamaterials—from passive to digital and programmable controls of electromagnetic waves

NASA Astrophysics Data System (ADS)

Cui, Tie Jun

2017-08-01

Since 2004, my group at Southeast University has been carrying out research into microwave metamaterials, which are classified into three catagories: metamaterials based on the effective medium model, plasmonic metamaterials for spoof surface plasmon polaritons (SPPs), and coding and programmable metamaterials. For effective-medium metamaterials, we have developed a general theory to accurately describe effective permittivity and permeability in semi-analytical forms, from which we have designed and realized a three dimensional (3D) wideband ground-plane invisibility cloak, a free-space electrostatic invisibility cloak, an electromagnetic black hole, optical/radar illusions, and radially anisotropic zero-index metamaterial for omni-directional radiation and a nearly perfect power combination of source array, etc. We have also considered the engineering applications of microwave metamaterials, such as a broadband and low-loss 3D transformation-optics lens for wide-angle scanning, a 3D planar gradient-index lens for high-gain radiations, and a random metasurface for reducing radar cross sections. In the area of plasmonic metamaterials, we proposed an ultrathin, narrow, and flexible corrugated metallic strip to guide SPPs with a small bending loss and radiation loss, from which we designed and realized a series of SPP passive devices (e.g. power divider, coupler, filter, and resonator) and active devices (e.g. amplifier and duplexer). We also showed a significant feature of the ultrathin SPP waveguide in overcoming the challenge of signal integrity in traditional integrated circuits, which will help build a high-performance SPP wireless communication system. In the area of coding and programmable metamaterials, we proposed a new measure to describe a metamaterial from the viewpoint of information theory. We have illustrated theoretically and experimentally that coding metamaterials composed of digital units can be controlled by coding sequences, leading to different functions. We realised that when the digital state of a coding unit is controlled by a field programmable gate array, the programmable metamaterial, which is capable of manipulating electromagnetic waves in real time, can generate many different functions.

Effect of a newly-devised nutritional guide based on self-efficacy for patients with type 2 diabetes in Japan over 2 years: 1-year intervention and 1-year follow-up studies.

PubMed

Yamamoto, Takuya; Moyama, Shota; Yano, Hideki

2017-03-01

We devised a new system called "Educational Guidance" (E-Guide) for nutritional education based on self-efficacy. The present study aimed to examine the effects of E-Guide use on glycemic control among patients with type 2 diabetes. We carried out an interventional and observational study that included 74 patients with type 2 diabetes. The extent of glycemic control in the 39 patients who received guidance through the E-Guide (E-Guide group) was compared with that of 35 patients who received conventional nutritional guidance (control group). We carried out a 1-year follow-up survey (subanalysis) based on the electronic health records of 18 patients from the E-guide group and 19 patients from the control group. These patients continued treatment at Hikone Municipal Hospital, Hikone, Shiga, Japan. Changes in glycated hemoglobin levels, body mass index and medication dose were examined from time of enrollment to the end of the 1-year intervention, and during the 1-year follow-up. Decreases in glycated hemoglobin levels were more pronounced in the E-Guide group than in the control group during the intervention period (P < 0.05). The levels further decreased during the follow-up period (P < 0.01). In the E-Guide group, body mass index decreased significantly throughout the follow-up period (P < 0.001). Additionally, increased medication doses were significantly less common in the E-Guide group than in the control group (P < 0.01). Intervention based on our "E-Guide" is more useful and powerful than the conventional methods for glycemic control and self-care behavior among patients with type 2 diabetes in Japan. © 2016 The Authors. Journal of Diabetes Investigation published by Asian Association for the Study of Diabetes (AASD) and John Wiley & Sons Australia, Ltd.

Intraoperative Cerenkov Imaging for Guiding Breast Cancer Surgery and Assessing Tumor Margins

DTIC Science & Technology

2012-12-01

Radiation Oncology. I regularly meet with both my mentor and co-mentor to discuss research progress. Over the summer, I have also taught a class on ...detection with a scintillator. Overall, due to the positron range, direct beta detection with a scintillator was limited to sources of radiation less than...luminescence was detected up to a depth of 5 mm (in tissue-mimicking material, given 100 uCi of activity). We found that one of the advantages of the

Technical Reference Manual: NATO Planning Guide for the Estimation of Chemical, Biological, Radiological, and Nuclear (CBRN), Casualties, Allied Medical Publication-8(C)

DTIC Science & Technology

2010-08-01

use of these submodels was reached. The details of the four agent-specific meetings, including the dates , locations, and participating SMEs are...Protected Armored Personnel Carrier – Closed 0% 0% Armored Personnel Carrier – Moving 50% 0% Armored Personnel Carrier – Open 100% 0% Earth Shelter 75...limited number of radioisotopes , typically emitting gamma and/or beta radiation. RDDs include at least two types of radiation sources: 1) point

Hanford Internal Dosimetry Program Manual, PNL-MA-552

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carbaugh, Eugene H.; Bihl, Donald E.; Maclellan, Jay A.

2009-09-24

This manual is a guide to the services provided by the Hanford Internal Dosimetry Program (IDP), which is operated by the Pacific Northwest National Laboratory.( ) for the U.S. Department of Energy Richland Operations Office, Office of River Protection and their Hanford Site contractors. The manual describes the roles of and relationships between the IDP and the radiation protection programs of the Hanford Site contractors. Recommendations and guidance are also provided for consideration in implementing bioassay monitoring and internal dosimetry elements of radiation protection programs.

Large volume flow-through scintillating detector

DOEpatents

Gritzo, Russ E.; Fowler, Malcolm M.

1995-01-01

A large volume flow through radiation detector for use in large air flow situations such as incinerator stacks or building air systems comprises a plurality of flat plates made of a scintillating material arranged parallel to the air flow. Each scintillating plate has a light guide attached which transfers light generated inside the scintillating plate to an associated photomultiplier tube. The output of the photomultiplier tubes are connected to electronics which can record any radiation and provide an alarm if appropriate for the application.

Misadministration of radiation therapy in veterinary medicine: a case report and literature review.

PubMed

Arkans, M M; Gieger, T L; Nolan, M W

2017-03-01

Recent technical advancements in radiation therapy have allowed for improved targeting of tumours and sparing nearby normal tissues, while simultaneously decreasing the risk for medical errors by incorporating additional safety checks into electronic medical record keeping systems. The benefits of these new technologies, however, depends on their proper integration and use in the oncology clinic. Despite the advancement of technology for treatment delivery and medical record keeping, misadministration errors have a significant impact on patient care in veterinary oncology. The first part of this manuscript describes a medical incident that occurred at an academic veterinary referral hospital, in a dog receiving a combination of stereotactic radiation therapy and full-course intensity-modulated, image-guided radiation therapy. The second part of the report is a literature review, which explores misadministration errors and novel challenges which arise with the implementation of advancing technologies in veterinary radiation oncology. © 2015 John Wiley & Sons Ltd.

[Optimization of the dose of radiation in shoulder arthrography].

PubMed

Campos, P A; Redondo, M V; Berná-Serna, J D; Reus, M; Martínez, F

2009-01-01

The aim of this study was to determine whether using a film with radiopaque coordinates placed over the region of interest to guide shoulder arthrography can reduce the dose of radiation received by patients. The entrance dose was obtained in 34 patients (mean age, 44 years; range, 15 to 75 years). The dose received by organs at risk and the effective dose were estimated with Monte Carlo techniques using the following input parameters: patient anatomy, examination geometry, and air kerma at the entrance to the patient without backscattering. Arthrography was performed with a remote controlled device and images were acquired digitally without fluoroscopy. The mean thickness of the shoulders studied was 14.6+/-2.1cm (9-20 cm). Images were obtained with 80+/-10 kVp (60-85 kVp) and 6.5+/-3.5 mAs (1.4-17 mAs). The mean time of irradiation for each patient was 20+/-6 ms (6.9-47.9 ms). The calculated air kerma was 0.41+/-0.19 mGy and the effective dose was 0.79+/-0.40 muSv. The technique described in this study has enabled us to reduce the dose of radiation received by patients undergoing shoulder arthrography in comparison with other techniques described in the literature and to ensure that the radiologist performing the procedure is not irradiated.

Quality control in cone-beam computed tomography (CBCT) EFOMP-ESTRO-IAEA protocol (summary report).

PubMed

de Las Heras Gala, Hugo; Torresin, Alberto; Dasu, Alexandru; Rampado, Osvaldo; Delis, Harry; Hernández Girón, Irene; Theodorakou, Chrysoula; Andersson, Jonas; Holroyd, John; Nilsson, Mats; Edyvean, Sue; Gershan, Vesna; Hadid-Beurrier, Lama; Hoog, Christopher; Delpon, Gregory; Sancho Kolster, Ismael; Peterlin, Primož; Garayoa Roca, Julia; Caprile, Paola; Zervides, Costas

2017-07-01

The aim of the guideline presented in this article is to unify the test parameters for image quality evaluation and radiation output in all types of cone-beam computed tomography (CBCT) systems. The applications of CBCT spread over dental and interventional radiology, guided surgery and radiotherapy. The chosen tests provide the means to objectively evaluate the performance and monitor the constancy of the imaging chain. Experience from all involved associations has been collected to achieve a consensus that is rigorous and helpful for the practice. The guideline recommends to assess image quality in terms of uniformity, geometrical precision, voxel density values (or Hounsfield units where available), noise, low contrast resolution and spatial resolution measurements. These tests usually require the use of a phantom and evaluation software. Radiation output can be determined with a kerma-area product meter attached to the tube case. Alternatively, a solid state dosimeter attached to the flat panel and a simple geometric relationship can be used to calculate the dose to the isocentre. Summary tables including action levels and recommended frequencies for each test, as well as relevant references, are provided. If the radiation output or image quality deviates from expected values, or exceeds documented action levels for a given system, a more in depth system analysis (using conventional tests) and corrective maintenance work may be required. Copyright © 2017. Published by Elsevier Ltd.

Safety of dose escalation by simultaneous integrated boosting radiation dose within the primary tumor guided by (18)FDG-PET/CT for esophageal cancer.

PubMed

Yu, Wen; Cai, Xu-Wei; Liu, Qi; Zhu, Zheng-Fei; Feng, Wen; Zhang, Qin; Zhang, Ying-Jian; Yao, Zhi-Feng; Fu, Xiao-Long

2015-02-01

To observe the safety of selective dose boost to the pre-treatment high (18)F-deoxyglucose (FDG) uptake areas of the esophageal GTV. Patients with esophageal squamous cell carcinoma were treated with escalating radiation dose of 4 levels, with a simultaneous integrated boost (SIB) to the pre-treatment 50% SUVmax area of the primary tumor. Patients received 4 monthly cycles of cisplatin and fluorouracil. Dose-limiting toxicity (DLT) was defined as any Grade 3 or higher acute toxicities causing continuous interruption of radiation for over 1 week. From April 2012 to February 2014, dose has been escalated up to LEVEL 4 (70Gy). All of the 25 patients finished the prescribed dose without DLT, and 10 of them developed Grade 3 acute esophagitis. One patient of LEVEL 2 died of esophageal hemorrhage within 1 month after completion of radiotherapy, which was not definitely correlated with treatment yet. Late toxicities remained under observation. With median follow up of 8.9months, one-year overall survival and local control was 69.2% and 77.4%, respectively. Dose escalation in esophageal cancer based on (18)FDG-PET/CT has been safely achieved up to 70Gy using the SIB technique. Acute toxicities were well tolerated, whereas late toxicities and long-term outcomes deserved further observation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Du, Shisuo; Lockamy, Virginia; Zhou, Lin

Purpose: To implement clinical stereotactic body radiation therapy (SBRT) using a small animal radiation research platform (SARRP) in a genetically engineered mouse model of lung cancer. Methods and Materials: A murine model of multinodular Kras-driven spontaneous lung tumors was used for this study. High-resolution cone beam computed tomography (CBCT) imaging was used to identify and target peripheral tumor nodules, whereas off-target lung nodules in the contralateral lung were used as a nonirradiated control. CBCT imaging helps localize tumors, facilitate high-precision irradiation, and monitor tumor growth. SBRT planning, prescription dose, and dose limits to normal tissue followed the guidelines set by RTOGmore » protocols. Pathologic changes in the irradiated tumors were investigated using immunohistochemistry. Results: The image guided radiation delivery using the SARRP system effectively localized and treated lung cancer with precision in a genetically engineered mouse model of lung cancer. Immunohistochemical data confirmed the precise delivery of SBRT to the targeted lung nodules. The 60 Gy delivered in 3 weekly fractions markedly reduced the proliferation index, Ki-67, and increased apoptosis per staining for cleaved caspase-3 in irradiated lung nodules. Conclusions: It is feasible to use the SARRP platform to perform dosimetric planning and delivery of SBRT in mice with lung cancer. This allows for preclinical studies that provide a rationale for clinical trials involving SBRT, especially when combined with immunotherapeutics.« less

Radiation fields from neutron generators shielded with different materials

NASA Astrophysics Data System (ADS)

Chichester, D. L.; Blackburn, B. W.

2007-08-01

As a general guide for assessing radiological conditions around a DT neutron generator numerical modeling has been performed to assess neutron and photon dose profiles for a variety of shield materials ranging from 1 to 100 cm thick. In agreement with accepted radiation safety practices high-Z materials such as bismuth and lead have been found to be ineffective biological shield materials, owing in part to the existence of (n,2n) reaction channels available with 14.1 MeV DT neutrons, while low-Z materials serve as effective shields for these sources. Composite materials such as a mixture of polyethylene and bismuth, or regular concrete, are ideal shield materials for neutron generator radiation because of their ability to attenuate internally generated photon radiation resulting from neutron scattering and capture within the shields themselves.

Dengue and Chikungunya Vector Control Pocket Guide

USDA-ARS?s Scientific Manuscript database

This technical guide consolidates information and procedures for surveillance and control of mosquitoes that transmit dengue and chikungunya viruses. The guide focuses on mosquitoes that transmit dengue but also makes reference to chikungunya and yellow fever because the pathogens that cause these ...

Technical Note: Mobile accelerator guidance using an optical tracker during docking in IOERT procedures.

PubMed

Marinetto, Eugenio; Victores, Juan González; García-Sevilla, Mónica; Muñoz, Mercedes; Calvo, Felipe Ángel; Balaguer, Carlos; Desco, Manuel; Pascau, Javier

2017-10-01

Intraoperative electron radiation therapy (IOERT) involves the delivery of a high radiation dose during tumor resection in a shorter time than other radiation techniques, thus improving local control of tumors. However, a linear accelerator device is needed to produce the beam safely. Mobile linear accelerators have been designed as dedicated units that can be moved into the operating room and deliver radiation in situ. Correct and safe dose delivery is a key concern when using mobile accelerators. The applicator is commonly fixed to the patient's bed to ensure that the dose is delivered to the prescribed location, and the mobile accelerator is moved to dock the applicator to the radiation beam output (gantry). In a typical clinical set-up, this task is time-consuming because of safety requirements and the limited degree of freedom of the gantry. The objective of this study was to present a navigation solution based on optical tracking for guidance of docking to improve safety and reduce procedure time. We used an optical tracker attached to the mobile linear accelerator to track the prescribed localization of the radiation collimator inside the operating room. Using this information, the integrated navigation system developed computes the movements that the mobile linear accelerator needs to perform to align the applicator and the radiation gantry and warns the physician if docking is unrealizable according to the available degrees of freedom of the mobile linear accelerator. Furthermore, we coded a software application that connects all the necessary functioning elements and provides a user interface for the system calibration and the docking guidance. The system could safeguard against the spatial limitations of the operating room, calculate the optimal arrangement of the accelerator and reduce the docking time in computer simulations and experimental setups. The system could be used to guide docking with any commercial linear accelerator. We believe that the docking navigator we present is a major contribution to IOERT, where docking is critical when attempting to reduce surgical time, ensure patient safety and guarantee that the treatment administered follows the radiation oncologist's prescription. © 2017 American Association of Physicists in Medicine.

GUIDES TO POLLUTION PREVENTION: THE AUTO REPAIR INDUSTRY

EPA Science Inventory

Automotive maintenance and repair shops generate a variety of waste streams during activities such as replacing fluids (e.g., motor oil, radiator coolant, transmission fluid, brake fluid), replacing non-repairable parts (e.g., brake shoes/pads, shocks, batteries, belts, mufflers,...

The phase transition in VO 2 probed using x-ray, visible and infrared radiations

DOE PAGES

Kumar, Suhas; Strachan, John Paul; Kilcoyne, A. L. David; ...

2016-02-15

Vanadium dioxide (VO 2) is a model system that has been used to understand closely occurring multiband electronic (Mott) and structural (Peierls) transitions for over half a century due to continued scientific and technological interests. Among the many techniques used to study VO 2, the most frequently used involve electromagnetic radiation as a probe. Understanding of the distinct physical information provided by different probing radiations is incomplete, mostly owing to the complicated nature of the phase transitions. Here, we use transmission of spatially averaged infrared (λ = 1.5 μm) and visible (λ = 500 nm) radiations followed by spectroscopy andmore » nanoscale imaging using x-rays (λ = 2.25–2.38 nm) to probe the same VO 2 sample while controlling the ambient temperature across its hysteretic phase transitions and monitoring its electrical resistance. We directly observed nanoscale puddles of distinct electronic and structural compositions during the transition. The two main results are that, during both heating and cooling, the transition of infrared and visible transmission occurs at significantly lower temperatures than the Mott transition, and the electronic (Mott) transition occurs before the structural (Peierls) transition in temperature. We use our data to provide insights into possible microphysical origins of the different transition characteristics. We highlight that it is important to understand these effects because small changes in the nature of the probe can yield quantitatively, and even qualitatively, different results when applied to a non-trivial multiband phase transition. Our results guide more judicious use of probe type and interpretation of the resulting data.« less

Occupational Health Risks in Cardiac Catheterization Laboratory Workers.

PubMed

Andreassi, Maria Grazia; Piccaluga, Emanuela; Guagliumi, Giulio; Del Greco, Maurizio; Gaita, Fiorenzo; Picano, Eugenio

2016-04-01

Orthopedic strain and radiation exposure are recognized risk factors in personnel staff performing fluoroscopically guided cardiovascular procedures. However, the potential occupational health effects are still unclear. The purpose of this study was to examine the prevalence of health problems among personnel staff working in interventional cardiology/cardiac electrophysiology and correlate them with the length of occupational radiation exposure. We used a self-administered questionnaire to collect demographic information, work-related information, lifestyle-confounding factors, all current medications, and health status. A total number of 746 questionnaires were properly filled comprising 466 exposed staff (281 males; 44±9 years) and 280 unexposed subjects (179 males; 43±7years). Exposed personnel included 218 interventional cardiologists and electrophysiologists (168 males; 46±9 years); 191 nurses (76 males; 42±7 years), and 57 technicians (37 males; 40±12 years) working for a median of 10 years (quartiles: 5-24 years). Skin lesions (P=0.002), orthopedic illness (P<0.001), cataract (P=0.003), hypertension (P=0.02), and hypercholesterolemia (P<0.001) were all significantly higher in exposed versus nonexposed group, with a clear gradient unfavorable for physicians over technicians and nurses and for longer history of work (>16 years). In highly exposed physicians, adjusted odds ratio ranged from 1.7 for hypertension (95% confidence interval: 1-3; P=0.05), 2.9 for hypercholesterolemia (95% confidence interval: 1-5; P=0.004), 4.5 for cancer (95% confidence interval: 0.9-25; P=0.06), to 9 for cataract (95% confidence interval: 2-41; P=0.004). Health problems are more frequently observed in workers performing fluoroscopically guided cardiovascular procedures than in unexposed controls, raising the need to spread the culture of safety in the cath laboratory. © 2016 American Heart Association, Inc.

Effect of intra-fraction motion on the accumulated dose for free-breathing MR-guided stereotactic body radiation therapy of renal-cell carcinoma

NASA Astrophysics Data System (ADS)

Stemkens, Bjorn; Glitzner, Markus; Kontaxis, Charis; de Senneville, Baudouin Denis; Prins, Fieke M.; Crijns, Sjoerd P. M.; Kerkmeijer, Linda G. W.; Lagendijk, Jan J. W.; van den Berg, Cornelis A. T.; Tijssen, Rob H. N.

2017-09-01

Stereotactic body radiation therapy (SBRT) has shown great promise in increasing local control rates for renal-cell carcinoma (RCC). Characterized by steep dose gradients and high fraction doses, these hypo-fractionated treatments are, however, prone to dosimetric errors as a result of variations in intra-fraction respiratory-induced motion, such as drifts and amplitude alterations. This may lead to significant variations in the deposited dose. This study aims to develop a method for calculating the accumulated dose for MRI-guided SBRT of RCC in the presence of intra-fraction respiratory variations and determine the effect of such variations on the deposited dose. For this, RCC SBRT treatments were simulated while the underlying anatomy was moving, based on motion information from three motion models with increasing complexity: (1) STATIC, in which static anatomy was assumed, (2) AVG-RESP, in which 4D-MRI phase-volumes were time-weighted, and (3) PCA, a method that generates 3D volumes with sufficient spatio-temporal resolution to capture respiration and intra-fraction variations. Five RCC patients and two volunteers were included and treatments delivery was simulated, using motion derived from subject-specific MR imaging. Motion was most accurately estimated using the PCA method with root-mean-squared errors of 2.7, 2.4, 1.0 mm for STATIC, AVG-RESP and PCA, respectively. The heterogeneous patient group demonstrated relatively large dosimetric differences between the STATIC and AVG-RESP, and the PCA reconstructed dose maps, with hotspots up to 40% of the D99 and an underdosed GTV in three out of the five patients. This shows the potential importance of including intra-fraction motion variations in dose calculations.

Patient doses from fluoroscopically guided cardiac procedures in pediatrics

NASA Astrophysics Data System (ADS)

Martinez, L. C.; Vano, E.; Gutierrez, F.; Rodriguez, C.; Gilarranz, R.; Manzanas, M. J.

2007-08-01

Infants and children are a higher risk population for radiation cancer induction compared to adults. Although some values on pediatric patient doses for cardiac procedures have been reported, data to determine reference levels are scarce, especially when compared to those available for adults in diagnostic and therapeutic procedures. The aim of this study is to make a new contribution to the scarce published data in pediatric cardiac procedures and help in the determination of future dose reference levels. This paper presents a set of patient dose values, in terms of air kerma area product (KAP) and entrance surface air kerma (ESAK), measured in a pediatric cardiac catheterization laboratory equipped with a biplane x-ray system with dynamic flat panel detectors. Cardiologists were properly trained in radiation protection. The study includes 137 patients aged between 10 days and 16 years who underwent diagnostic catheterizations or therapeutic procedures. Demographic data and technical details of the procedures were also gathered. The x-ray system was submitted to a quality control programme, including the calibration of the transmission ionization chamber. The age distribution of the patients was 47 for <1 year; 52 for 1-<5 years; 25 for 5-<10 years and 13 for 10-<16 years. Median values of KAP were 1.9, 2.9, 4.5 and 15.4 Gy cm2 respectively for the four age bands. These KAP values increase by a factor of 8 when moving through the four age bands. The probability of a fatal cancer per fluoroscopically guided cardiac procedure is about 0.07%. Median values of ESAK for the four age bands were 46, 50, 56 and 163 mGy, which lie far below the threshold for deterministic effects on the skin. These dose values are lower than those published in previous papers.

Development of patient-controlled respiratory gating system based on visual guidance for magnetic-resonance image-guided radiation therapy.

PubMed

Kim, Jung-In; Lee, Hanyoung; Wu, Hong-Gyun; Chie, Eui Kyu; Kang, Hyun-Cheol; Park, Jong Min

2017-09-01

The aim of this study is to develop a visual guidance patient-controlled (VG-PC) respiratory gating system for respiratory-gated magnetic-resonance image-guided radiation therapy (MR-IGRT) and to evaluate the performance of the developed system. The near-real-time cine planar MR image of a patient acquired during treatment was transmitted to a beam projector in the treatment room through an optical fiber cable. The beam projector projected the cine MR images inside the bore of the ViewRay system in order to be visible to a patient during treatment. With this visual information, patients voluntarily controlled their respiration to put the target volume into the gating boundary (gating window). The effect of the presence of the beam projector in the treatment room on the image quality of the MRI was investigated by evaluating the signal-to-noise ratio (SNR), uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity with the VG-PC gating system. To evaluate the performance of the developed system, we applied the VG-PC gating system to a total of seven patients; six patients received stereotactic ablative radiotherapy (SABR) and one patient received conventional fractionated radiation therapy. The projected cine MR images were visible even when the room light was on. No image data loss or additional time delay during delivery of image data were observed. Every indicator representing MRI quality, including SNR, uniformity, low-contrast detectability, high-contrast spatial resolution, and spatial integrity exhibited values higher than the tolerance levels of the manufacturer with the VG-PC gating system; therefore, the presence of the VG-PC gating system in the treatment room did not degrade the MR image quality. The average beam-off times due to respiratory gating with and without the VG-PC gating system were 830.3 ± 278.2 s and 1264.2 ± 302.1 s respectively (P = 0.005). Consequently, the total treatment times excluding the time for patient setup with and without the VG-PC gating system were 1453.3 ± 297.3 s and 1887.2 ± 469.6 s, respectively, on average (P = 0.005). The average number of beam-off events during whole treatment session was reduced from 457 ± 154 times to 195 ± 90 times by using the VG-PC gating system (P < 0.001). The developed system could improve treatment efficiency when performing respiratory-gated MR-IGRT. The VG-PC gating system could be applied to any kind of bore-type radiotherapy machine. © 2017 American Association of Physicists in Medicine.

A new multipurpose CO2 laser therapy instrument.

PubMed

Peng, X

1995-02-01

A new multipurpose CO2 laser therapy instrument has been developed. It is a highly efficient medical instrument. By use of high laser power density to coagulate, evaporate, and cut body tissue on the nidus, the operation can be controlled and has obvious curative effects. Unlike other kinds of CO2 laser therapy instruments, this device has an advanced switching power supply (SPS) and red guiding light system. With an overcurrent protective device, an overvoltage protective device, and a high-voltage shield device, it provides efficiency, stability, reliability, and low loss. The plastic casing does not leak electricity and the film switches are designed for clinical practice convenience. Additionally, the laser power is numerically displayed and can be set prior to the procedure. The distinct visible guiding light of the laser output makes the operation more convenient and accurate. Because of this unique design and properties, it is a leading model in China. The instrument can be widely used for surgery, gynecology, dermatology, and otolaryngology. The radiation therapy of low laser power density has the effect of being antiinflamatory, analgesic, and antipruritic, and promotes cure of the epithelium. Moreover, it is effective to treat all sorts of sprains, scapulohumeral periarthritis, arthritis, sciatica, and surface ulcers.

Achievement of radiative feedback control for long-pulse operation on EAST

NASA Astrophysics Data System (ADS)

Wu, K.; Yuan, Q. P.; Xiao, B. J.; Wang, L.; Duan, Y. M.; Chen, J. B.; Zheng, X. W.; Liu, X. J.; Zhang, B.; Xu, J. C.; Luo, Z. P.; Zang, Q.; Li, Y. Y.; Feng, W.; Wu, J. H.; Yang, Z. S.; Zhang, L.; Luo, G.-N.; Gong, X. Z.; Hu, L. Q.; Hu, J. S.; Li, J.

2018-05-01

The active feedback control of radiated power to prevent divertor target plates overheating during long-pulse operation has been developed and implemented on EAST. The radiation control algorithm, with impurity seeding via a supersonic molecular beam injection (SMBI) system, has shown great success in both reliability and stability. By seeding a sequence of short neon (Ne) impurity pulses with the SMBI from the outer mid-plane, the radiated power of the bulk plasma can be well controlled, and the duration of radiative control (feedforward and feedback) is 4.5 s during a discharge of 10 s. Reliable control of the total radiated power of bulk plasma has been successfully achieved in long-pulse upper single null (USN) discharges with a tungsten divertor. The achieved control range of {{f}rad} is 20%–30% in L-mode regimes and 18%–36% in H-mode regimes. The temperature of the divertor target plates was maintained at a low level during the radiative control phase. The peak particle flux on the divertor target was decreased by feedforward Ne injection in the L-mode discharges, while the Ne pulses from the SMBI had no influence on the peak particle flux because of the very small injecting volume. It is shown that although the radiated power increased, no serious reduction of plasma-stored energy or confinement was observed during the control phase. The success of the radiation control algorithm and current experiments in radiated power control represents a significant advance for steady-state divertor radiation and heat flux control on EAST for near-future long-pulse operation.

Device for calibrating a radiation detector system

DOEpatents

McFee, M.C.; Kirkham, T.J.; Johnson, T.H.

1994-12-27

A device is disclosed for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a ''shield plate'' or shell, and an opposing ''source plate'' containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects. 3 figures.

Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fabrikant, J.I.

1982-08-01

The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer-induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain for problems and difficulties in extrapolation from data obtained at high doses to low doses, and frommore » animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations, and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy.« less

Epidemiological studies on radiation carcinogenesis in human populations following acute exposure: nuclear explosions and medical radiation.

PubMed Central

Fabrikant, J. I.

1981-01-01

The present review provides an understanding of our current knowledge of the carcinogenic effect of low-dose radiation in man, and surveys the epidemiological studies of human populations exposed to nuclear explosions and medical radiation. Discussion centers on the contributions of quantitative epidemiology to present knowledge, the reliability of the dose-incidence data, and those relevant epidemiological studies that provide the most useful information for risk estimation of cancer induction in man. Reference is made to dose-incidence relationships from laboratory animal experiments where they may obtain, for problems and difficulties in extrapolation from data obtained at high doses to low doses, and from animal data to the human situation. The paper describes the methods of application of such epidemiological data for estimation of excess risk of radiation-induced cancer in exposed human populations and discusses the strengths and limitations of epidemiology in guiding radiation protection philosophy and public health policy. PMID:7043913

User's guide: Nimbus-7 Earth radiation budget narrow-field-of-view products. Scene radiance tape products, sorting into angular bins products, and maximum likelihood cloud estimation products

NASA Technical Reports Server (NTRS)

Kyle, H. Lee; Hucek, Richard R.; Groveman, Brian; Frey, Richard

1990-01-01

The archived Earth radiation budget (ERB) products produced from the Nimbus-7 ERB narrow field-of-view scanner are described. The principal products are broadband outgoing longwave radiation (4.5 to 50 microns), reflected solar radiation (0.2 to 4.8 microns), and the net radiation. Daily and monthly averages are presented on a fixed global equal area (500 sq km), grid for the period May 1979 to May 1980. Two independent algorithms are used to estimate the outgoing fluxes from the observed radiances. The algorithms are described and the results compared. The products are divided into three subsets: the Scene Radiance Tapes (SRT) contain the calibrated radiances; the Sorting into Angular Bins (SAB) tape contains the SAB produced shortwave, longwave, and net radiation products; and the Maximum Likelihood Cloud Estimation (MLCE) tapes contain the MLCE products. The tape formats are described in detail.

Device for calibrating a radiation detector system

DOEpatents

Mc Fee, Matthew C.; Kirkham, Tim J.; Johnson, Tippi H.

1994-01-01

A device for testing a radiation detector system that includes at least two arrays of radiation detectors that are movable with respect to each other. The device includes a "shield plate" or shell, and an opposing "source plate" containing a source of ionizing radiation. Guides are attached to the outer surface of the shell for engaging the forward ends of the detectors, thereby reproducibly positioning the detectors with respect to the source and with respect to each other, thereby ensuring that a predetermined portion of the radiation emitted by the source passes through the shell and reaches the detectors. The shell is made of an hydrogenous material having approximately the same radiological attenuation characteristics as composite human tissue. The source represents a human organ such as the lungs, heart, kidneys, heart, liver, spleen, pancreas, thyroid, testes, prostate, or ovaries. The source includes a source of ionizing radiation having a long half-life and an activity that is within the range typically searched for in human subjects.

Electromagnetic navigation system for CT-guided biopsy of small lesions.

PubMed

Appelbaum, Liat; Sosna, Jacob; Nissenbaum, Yizhak; Benshtein, Alexander; Goldberg, S Nahum

2011-05-01

The purpose of this study was to evaluate an electromagnetic navigation system for CT-guided biopsy of small lesions. Standardized CT anthropomorphic phantoms were biopsied by two attending radiologists. CT scans of the phantom and surface electromagnetic fiducial markers were imported into the memory of the 3D electromagnetic navigation system. Each radiologist assessed the accuracy of biopsy using electromagnetic navigation alone by targeting sets of nine lesions (size range, 8-14 mm; skin to target distance, 5.7-12.8 cm) under eight different conditions of detector field strength and orientation (n = 117). As a control, each radiologist also biopsied two sets of five targets using conventional CT-guided technique. Biopsy accuracy, number of needle passes, procedure time, and radiation dose were compared. Under optimal conditions (phantom perpendicular to the electromagnetic receiver at highest possible field strength), phantom accuracy to the center of the lesion was 2.6 ± 1.1 mm. This translated into hitting 84.4% (38/45) of targets in a single pass (1.1 ± 0.4 CT confirmations), which was significantly fewer than the 3.6 ± 1.3 CT checks required for conventional technique (p < 0.001). The mean targeting time was 38.8 ± 18.2 seconds per lesion. Including procedural planning (∼5.5 minutes) and final CT confirmation of placement (∼3.5 minutes), the full electromagnetic tracking procedure required significantly less time (551.6 ± 87.4 seconds [∼9 minutes]) than conventional CT (833.3 ± 283.8 seconds [∼14 minutes]) for successful targeting (p < 0.001). Less favorable conditions, including nonperpendicular relation between the axis of the machine and weaker field strength, resulted in statistically significant lower accuracy (3.7 ± 1 mm, p < 0.001). Nevertheless, first-pass biopsy accuracy was 58.3% (21/36) and second-pass (35/36) accuracy was 97.2%. Lesions farther from the skin than 20-25 cm were out of range for successful electromagnetic tracking. Virtual electromagnetic tracking appears to have high accuracy in needle placement, potentially reducing time and radiation exposure compared with those of conventional CT techniques in the biopsy of small lesions.

Ultrasound guided therapeutic injections of the cervical spine and brachial plexus.

PubMed

Cormick, Wes

2014-02-01

Introduction : Recent applications in ultrasound imaging include ultrasound assessment and ultrasound guided therapeutic injections of the spine and brachial plexus. Discussion : Ultrasound is an ideal modality for these regions as it allows accurate safe and quick injection of single or multiple sites. It has the added advantages of lack of ionising radiation, and can be done without requiring large expensive radiology equipment. Conclusion : Brachial plexus pathology may be present in patients presenting for shoulder symptoms where very little is found at imaging the shoulder. It is important to understand the anatomy and normal variants that may exist to be able to recognise when pathology is present. When pathology is demonstrated it is easy to do a trial of therapy with ultrasound guided injection of steroid around the nerve lesion. This review will outline the normal anatomy and variants and common pathology, which can be amenable to ultrasound guided injection of steroid.

SU-E-J-185: A Systematic Review of Breathing Guidance in Radiation Oncology and Radiology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pollock, S; Keall, P; Keall, R

Purpose: The advent of image-guided radiation therapy (IGRT) has led to dramatic improvements in the accuracy of treatment delivery in radiotherapy. Such advancements have highlighted the deleterious impact tumor motion can have on both image quality and radiation treatment delivery. One approach to reducing tumor motion is the use of breathing guidance systems during imaging and treatment. A review of such research had not yet been performed, it was therefore our aim to perform a systematic review of breathing guidance interventions within the fields of radiation oncology and radiology. Methods: Results of online database searches were filtered in accordance tomore » a set of eligibility criteria. The search, filtration, and analysis of articles were conducted in accordance with the PRISMAStatement reporting standard (Preferred Reporting Items for Systematic reviews and Meta-Analyses) utilizing the PICOS approach (Participants, Intervention, Comparison, Outcome, Study design). Participants: Cancer patients, healthy volunteers. Intervention: Biofeedback breathing guidance systems. Comparison: No breathing guidance of the same breathing type. Outcome: Regularity of breathing signal and anatomic/tumor motion, medical image quality, radiation treatment margins and coverage, medical imaging and radiation treatment times. Study design: Quantitative and controlled prospective or retrospective trials. Results: The systematic search yielded a total of 479 articles, which were filtered down to 27 relevant articles in accordance to the eligibility criteria. The vast majority of investigated outcomes were significantly positively impacted by the use of breathing guidance; however, this was dependent upon the nature of the breathing guidance system and study design. In 25/27 studies significant improvements from the use of breathing guidance were observed. Conclusion: The results found here indicate that further clinical studies are warranted which quantify more comprehensively the clinical impact of The results found here indicate that further clinical studies are warranted which quantify more comprehensively the clinical impact of breathing guidance interventions.« less

To Keep and Bear Arms: Gun Control and the Second Amendment. Teacher's Guide.

ERIC Educational Resources Information Center

Edwards, Amy N.; Walker, Tim

This teacher's guide is designed to accompany the two-part videotape "To Keep and Bear Arms: Gun Control and the Second Amendment." The videotape and teacher's guide should help students to: (1) understand the history of the Second Amendment; (2) examine how guns and gun control laws affect people's lives; (3) compare and contrast the…

An operating guide for the control of residential cut-through traffic.

DOT National Transportation Integrated Search

1990-01-01

The objective of this operating guide was to provide direction in conducting studies in accordance with the Policy and Procedures for Control of Residential Cut-Through Traffic" of the Virginia Department of Transportation. The guide is in eight part...

MR-guided transcranial brain HIFU in small animal models

PubMed Central

Larrat, Benoît; Pernot, Mathieu; Aubry, Jean-François; Dervishi, Elvis; Sinkus, Ralph; Seilhean, Danielle; Marie, Yannick; Boch, Anne-Laure; Fink, Mathias; Tanter, Mickaël

2010-01-01

Recent studies have demonstrated the feasibility of transcranial High Intensity Focused Ultrasound (HIFU) therapy in the brain using adaptive focusing techniques. However, the complexity of the procedures imposes to provide an accurate targeting, monitoring and control of this emerging therapeutic modality in order to ensure the safety of the treatment and avoid potential damaging effects of ultrasound on healthy tissues. For these purposes, a complete workflow and setup for HIFU treatment under Magnetic Resonance (MR) guidance is proposed and implemented in rats. For the first time, tissue displacements induced by the acoustic radiation force are detected in vivo in brain tissues and measured quantitatively using motion-sensitive MR sequences. Such a valuable target control prior to treatment assesses the quality of the focusing pattern in situ and enables to estimate the acoustic intensity at focus. This MR-Acoustic radiation force imaging is then correlated with conventional MR-Thermometry sequences which are used to follow the temperature changes during the HIFU therapeutic session. Last, pre and post treatment Magnetic Resonance Elastography (MRE) datasets are acquired and evaluated as a new potential way to non invasively control the stiffness changes due to the presence of thermal necrosis. As a proof of concept, MRguided HIFU is performed in vitro in turkey breast samples and in vivo in transcranial rat brain experiments. The experiments are conducted using a dedicated MR compatible HIFU setup in a high field MRI scanner (7T). Results obtained on rats confirmed that both the MR localization of the US focal point and the pre and post HIFU measurement of the tissue stiffness, together with temperature control during HIFU are feasible and valuable techniques for an efficient monitoring of HIFU in the brain. Brain elasticity appears to be more sensitive to the presence of oedema than to tissue necrosis. PMID:20019400

Semiconductor laser having a non-absorbing passive region with beam guiding

NASA Technical Reports Server (NTRS)

Botez, Dan (Inventor)

1986-01-01

A laser comprises a semiconductor body having a pair of end faces and including an active region comprising adjacent active and guide layers which is spaced a distance from the end face and a passive region comprising adjacent non-absorbing guide and mode control layers which extends between the active region and the end face. The combination of the guide and mode control layers provides a weak positive index waveguide in the lateral direction thereby providing lateral mode control in the passive region between the active region and the end face.

Sub-mm Scale Fiber Guided Deep/Vacuum Ultra-Violet Optical Source for Trapped Mercury Ion Clocks

NASA Technical Reports Server (NTRS)

Yi, Lin; Burt, Eric A.; Huang, Shouhua; Tjoelker, Robert L.

2013-01-01

We demonstrate the functionality of a mercury capillary lamp with a diameter in the sub-mm range and deep ultraviolet (DUV)/ vacuum ultraviolet (VUV) radiation delivery via an optical fiber integrated with the capillary. DUV spectrum control is observed by varying the fabrication parameters such as buffer gas type and pressure, capillary diameter, electrical resonator design, and temperature. We also show spectroscopic data of the 199Hg+ hyper-fine transition at 40.5GHz when applying the above fiber optical design. We present efforts toward micro-plasma generation in hollow-core photonic crystal fiber with related optical design and theoretical estimations. This new approach towards a more practical DUV optical interface could benefit trapped ion clock developments for future ultra-stable frequency reference and time-keeping applications.

A nurse-guided, basal-prandial insulin treatment protocol for achieving glycaemic control of hospitalized, non-critically ill diabetes patients, is non-inferior to physician-guided therapy: A pivotal, nurse-empowerment study.

PubMed

Segal, Gad; Karniel, Eli; Mahagna, Ahmed; Kaa'dan, Fadi; Levi, Zehava; Balik, Chaya

2015-12-01

Basal-prandial insulin is established for glycaemic control for hospitalized, type 2 diabetes patients. Empowering nurses to guide such protocols could be advantageous.The study aims to comparatively assess the efficacy and safety of glycaemic control by a nurse-guided protocol with physician-guided therapy. It also aims to assess the impact of empowerment on the nurses' sense of competence. This is a prospective, controlled, randomized, single-blinded study. Validated protocol utilizing basal-prandial insulin was used. Glycaemic control was the primary efficacy outcome, whereas hypoglycaemia and laboratory parameters were followed for safety. Assessment of nurses' psychological empowerment was done. One hundred fifty-eight treatment days of 53 patients were included. Patients were randomized to either study group (n = 27) or control group (n = 26). Glycaemia deviation from liberal range (60-300 mg/dL) was 7.4% of days for nurse-guided, basal-prandial insulin treatment protocol (NGP) and 7.84% for physician-guided therapy (PGT), P = 0.901. Rate of glycaemia deviation from the strict range (100-180 mg/dL) was 49.76% for NGP and 47.38% for PGT, P = 0.703. Mean range of daily deviation was similar (77.05 mg/dL for NGP and 76.04 mg/dL for PGT, P = 0.93). There were no significant differences in safety parameters. An empowerment questionnaire showed tendency for increased nurses' sense of competence. Nurse-guided protocol is non-inferior to physician-guided treatment in efficacy and safety parameters. Nurses' sense of competence was positively influenced. © 2014 Wiley Publishing Asia Pty Ltd.

The quality of radiation care: the results of focus group interviews and concept mapping to explore the patient's perspective.

PubMed

Nijman, Jessica L; Sixma, Herman; van Triest, Baukelien; Keus, Ronald B; Hendriks, Michelle

2012-01-01

In this study, we explore the quality aspects of radiation care from the patient's perspective in order to develop a draft Consumer Quality Index (CQI) Radiation Care instrument. Four focus group discussions with (former) cancer patients were held to explore the aspects determining the quality of radiation care. The list of aspects generated was categorised based on similarity and importance in a concept mapping procedure. Four focus group discussions revealed seven main themes related to the quality of radiation care: information provision, a patient-centred approach, professional competence, planning and waiting times, accessibility, cooperation and communication, and follow-up care. Results of concept mapping procedures revealed which items the patients considered to be most important. A radiation oncologist who is up to date about the patient's file is of paramount importance for cancer patients receiving radiotherapy. The quality aspects found through focus group discussions provided useful insight into how patients experience radiation care. Furthermore, concept mapping made these results more solid. To evaluate the quality of radiation care from the patient's perspective, these quality aspects will be guiding in the development of a CQI Radiation Care. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.