Read by QxMD icon Read

Radiation dose measurements

Motahare Soufi, Alireza Kamali-Asl, Parham Geramifar, Arman Rahmim
PURPOSE: Determination of intra-tumor high-uptake area using 2-deoxy-2-[(18)F]fluoro-D-glucose ([(18)F]FDG) positron emission tomography (PET) imaging is an important consideration for dose painting in radiation treatment applications. The aim of our study was to develop a framework towards automated segmentation and labeling of homogeneous vs. heterogeneous tumors in clinical lung [(18)F]FDG-PET with the capability of intra-tumor high-uptake region delineation. PROCEDURES: We utilized and extended a fuzzy random walk PET tumor segmentation algorithm to delineate intra-tumor high-uptake areas...
October 21, 2016: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
A A Dos Reis, L Bertelli, W O Sousa
Radiological or nuclear emergency situations could lead to incorporation of radionuclides by the population. Intakes of radionuclides can be evaluated through measurements of radionuclides present in organs and tissues, or in urinary and/or fecal excretion. In an emergency situation involving a large number of people, the decision to provide medical treatment to an individual will likely be based on a single measurement. For that purpose, the National Council on Radiation Protection and Measurements (NCRP) has presented the Clinical Decision Guide (CDG) quantity, which corresponds to an intake amount of a radionuclide by an individual for which treatment is recommended...
October 7, 2016: Radiation Protection Dosimetry
Britta Langen, Nils Rudqvist, Khalil Helou, Eva B Forssell-Aronsson
INTRODUCTION: Targeted α-therapy is a promising treatment option for various types of malignant tumors. Radiolabeled cancer-seeking agents, however, undergo degradation resulting in a certain percentage of free radionuclide in the body. The radiohalogen (211)At accumulates in various tissues with specifically high uptake in the thyroid. When normal thyroid function is disturbed due to ionizing radiation (IR) exposure, deleterious effects can occur in tissues that depend on thyroid hormone (TH) regulation for normal physiological function...
October 20, 2016: Journal of Nuclear Medicine: Official Publication, Society of Nuclear Medicine
B Behnke, O Hupe, R Behrens
Conversion coefficients (CCs) are an essential vehicle in radiation protection for the determination of the dose (rate) of a given radiation field. According to the current draft of the revision of international standard ISO 4037, an X-ray field is a reference field if the CCs of the field match the tabulated ISO values within 2%. Deviations of the high-voltage (HV) tube-potential from its nominal value influence the resulting spectra and change the corresponding CCs. This work investigates the maximum allowable deviation of the HV from its nominal value such that the requirements of ISO 4037 remain fulfilled...
October 20, 2016: Radiation Protection Dosimetry
Matthew D Hall, Timothy E Schultheiss, David D Smith, Marwan G Fakih, Jeffrey Y C Wong, Yi-Jen Chen
BACKGROUND: Neoadjuvant chemoradiation therapy (CRT) increases pathological complete response (pCR) rates compared to radiotherapy alone in patients with stage II-III rectal cancer. Limited evidence addresses whether radiotherapy dose escalation further improves pCR rates. Our purpose is to measure the effects of radiotherapy dose and other factors on post-therapy pathologic tumor (ypT) and nodal stage in rectal cancer patients treated with neoadjuvant CRT followed by mesorectal excision...
October 20, 2016: Acta Oncologica
Anton S Becker, Katharina Martini, Kai Higashigaito, Roman Guggenberger, Gustav Andreisek, Thomas Frauenfelder
OBJECTIVE: The purpose of this study was to quantitatively and qualitatively determine the impact of radiation dose reduction on the image noise and quality of tomosynthesis studies of the wrist. MATERIALS AND METHODS: Imaging of six cadaver wrists was performed with tomosynthesis in anteroposterior position at a tube voltage of 60 kV and tube current of 80 mA and subsequently at 60 or 50 kV with different tube currents of 80, 40, or 32 mA. Dose-area products (DAP) were obtained from the electronically logged protocol...
October 20, 2016: AJR. American Journal of Roentgenology
Ferda Hoşgörler, Didem Keleş, Serpil Tanrıverdi-Akhisaroğlu, Şeniz İnanç, Mustafa Akhisaroğlu, Ülker Cankurt, Zekiye Aydoğdu, Ahmet Deniz Uçar, Oğuz Çetinayak, Gülgün Oktay, Sevil Gönenç Arda
BACKGROUND: Matrix metalloproteinase (MMP) inhibitors decrease inflammation in normal tissues and suppress cancer progress in normal tissues. Valproic acid (VA) and doxycycline (DX) are MMP inhibitors that have radio-protective effects. Their ability to inhibit MMPs in irradiated tissue is unknown and the role of MMPs in radio-protective effects has not been tested to date. AIMS: The purpose of this study was to examine whether administration of VA and DX to rats before irradiation affects tissue inflammation and apoptosis in the early phase of radiation, and whether the effect of these drugs is mediated by MMP inhibition...
September 2016: Balkan Medical Journal
Hideki Kato, Keita Sakai, Mizuki Uchiyama, Kentaro Suzuki
The diagnostic reference levels (DRLs) of the general X-ray radiography are defined by the absorbed dose of air at the entrance surface with backscattered radiation from a scattering medium. Generally, the entrance surface dose of the general X-ray radiography is calculated from measured air kerma of primary X-ray multiplied by a backscatter factor (BSF). However, the BSF data employed at present used water for scattering medium, and was calculated based on the water-absorbed dose by incident primary photons and backscattered photons from the scattering medium...
2016: Nihon Hoshasen Gijutsu Gakkai Zasshi
Uwe Schneider, Fabiano Vasi, Jürgen Besserer
BACKGROUND AND PURPOSE: When fractionation schemes for hypofractionation and stereotactic body radiotherapy are considered, a reliable cell survival model at high dose is needed for calculating doses of similar biological effectiveness. An alternative to the LQ-model is the track-event theory which is based on the probabilities for one- and two two-track events. A one-track-event (OTE) is always represented by at least two simultaneous double strand breaks. A two-track-event (TTE) results in one double strand break...
2016: PloS One
Meng Li, Shichao Feng, Ning Wu, Li Zhang
OBJECTIVE: The aim of our study was to assess radiation dose reduction and image quality for enhanced chest CT examinations with a scout-based automated tube potential selection technique (kV Assist) compared with a standard 120-kV protocol. METHODS: Prospective study of enhanced chest CT examinations was performed in 100 consecutive patients with kV Assist and in 100 consecutive patients with conventional 120-kV protocol on a multislice CT (Discovery CT750 HD)...
October 18, 2016: Journal of Computer Assisted Tomography
Ben Horsburgh, Mike Higgins
Purpose - To quantify through environmental audit the radiation dose urologists receive during surgery in the lithotomy position, and quantify the dose reduction achieved by altering techniques. Materials and Methods - Simulated surgery in the lithotomy position using an anthropomorphic phantom as a patient and a SimMan mannequin as the surgeon. Pulsed fluoroscopy, focus to skin distance, collimation and lead shielding at the table end were individually and collectively introduced following a control study...
October 19, 2016: Journal of Endourology
Charbel Saade, Fadi El-Merhi, Bassam El-Achkar, Racha Kerek, Thomas J Vogl, Gilbert Georges Maroun, Lamia Jamjoom, Hussain Al-Mohiy, Lena Naffa
CLINICAL RELEVANCE STATEMENT: Caudocranial scan direction and contrast injection timing based on measured patient vessel dynamics can significantly improve arterial and aneurysmal opacification and reduce both contrast and radiation dose in the assessment of thoracic aortic aneurysms (TAA) using helical thoracic computed tomography angiography (CTA). OBJECTIVES: To investigate opacification of the thoracic aorta and TAA using a caudocranial scan direction and a patient-specific contrast protocol...
October 17, 2016: Journal of Computer Assisted Tomography
Xue Rui, Yannan Jin, Paul F FitzGerald, Mingye Wu, Adam M Alessio, Paul E Kinahan, Bruno De Man
Computed tomography (CT) has been used for a variety of applications, two of which include diagnostic imaging and attenuation correction for PET or SPECT imaging. Ideally, the x-ray tube spectrum should be optimized for the specific application to minimize the patient radiation dose while still providing the necessary information. In this study, we proposed a projection-based analytic approach for the analysis of contrast, noise, and bias. Dose normalized contrast to noise ratio (CNRD), inverse noise normalized by dose (IND) and bias are used as evaluation metrics to determine the optimal x-ray spectrum...
November 7, 2016: Physics in Medicine and Biology
Yetunde A Onimode, John E Ejeh, Akintunde T Orunmuyi
OBJECTIVE: Radioactive iodine therapy (RAIT) is established as an efficient means of treating toxic goiter (TG) globally. The field of nuclear medicine (NM) still appears novel to many Nigerian clinicians and patients. A culturally embedded dread of radiation may raise ethical and moral concerns about potential adverse effects in the wake of RAIT in our setting. An adverse drug reaction may be described as "a response to a drug which is noxious and unintended, and which occurs at doses normally used in man"...
October 5, 2016: Molecular Imaging and Radionuclide Therapy
Nnamdi Norbert Jibiri, Tawakalitu Oluwatoyin Akintunde, Musa Yusuf Dambele, Christopher Jimoh Olowookere
OBJECTIVE: The practice of regular dose measurement helps to ascertain the level of occupational dose delivered to the staff involved in diagnostic procedures. This study was carried out to evaluate the dose exposed to the hands of radiologists and a radiologic technologist carrying out HSG and radionuclide bone scan examinations in several hospitals in Nigeria. METHODS: Radiation doses exposed to the hands of radiologists and a technician carrying out hysterosalpingography (HSG) and bone scan procedures were measured using calibrated thermo-luminescent dosimeters...
October 5, 2016: Molecular Imaging and Radionuclide Therapy
Yoann Pointreau, Nicolas Azzopardi, David Ternant, Gilles Calais, Gilles Paintaud
BACKGROUND: A retrospective study was conducted to analyze interindividual variability of cetuximab pharmacokinetics and its influence on survival (Progression Free Survival - PFS and overall survival - OS) in a cohort of head and neck squamous cell carcinoma (HNSCC). METHODS: Thirty-four patients received cetuximab as an infusion loading dose of 400 mg/m followed by weekly infusions of 250 mg/m. Twenty-one patients had locally advanced HNSCC (LAHNSCC) and thirteen had metastatic/recurrent HNSCC (MHNSCC)...
July 4, 2016: Therapeutic Drug Monitoring
Zheng Lu, Teng-Hui Dong, Pei-Ren Si, Wei Shen, Yi-Liang Bi, Min Min, Xin Chen, Yan Liu
BACKGROUND: Perineural invasion (PNI) is a histopathological characteristic of pancreatic cancer (PanCa). The aim of this study was to observe the treatment effect of continuous low-dose-rate (CLDR) irradiation to PNI and assess the PNI-related pain relief caused by iodine-125 ( 125 I) seed implantation. METHODS: The in vitro PNI model established by co-culture with dorsal root ganglion (DRG) and cancer cells was interfered under 2 and 4 Gy of 125 I seeds CLDR irradiation...
2016: Chinese Medical Journal
Michael S Kent, Davide Berlato, Isabelle Vanhaezebrouck, Ira K Gordon, Katherine S Hansen, Alain P Theon, Randall W Holt, Earl A Trestrail
Radiation therapy of the head and neck can result in mucositis and other acute affects in the oral cavity. This prospective pilot study evaluated a novel, intraoral, beam-blocking device for use during imaging and therapeutic procedures. The beam-blocking device was made from a metal alloy inserted into a coated frozen dessert mold (Popsicle® Mold, Cost Plus World Market, Oakland, CA). The device was designed so that it could be inserted into an outer shell, which in turn allowed it to be placed or removed depending on the need due to beam configuration...
October 17, 2016: Veterinary Radiology & Ultrasound
Yeongchull Choi, Jaeyoung Kim, Jung Jeung Lee, Jae Kwan Jun, Won Jin Lee
OBJECTIVES: Diagnostic medical radiation workers in Korea have been officially monitored for their occupational radiation doses since 1996. The purpose of this study was to design models for reconstructing unknown individual radiation doses to which diagnostic radiation technologists were exposed before 1996. METHODS: Radiation dose reconstruction models were developed by using cross-sectional survey data and the personal badge doses of 8167 radiologic technologists...
September 2016: Journal of Preventive Medicine and Public Health, Yebang Ŭihakhoe Chi
Satish C Uniyal, Vineet Chaturvedi, Sunil D Sharma, Anurag Rawat
Cardiac interventions often result in high radiation dose to patient's skin, so a reliable indicator in terms of a commonly used dose descriptor is required to monitor skin exposures. In the present study, Gafchromic XR-RV3 film was used to measure the peak skin dose (PSD) during 40 coronary angiography (CA) and 50 percutaneous transluminal coronary angioplasty (PTCA) procedures. Corresponding values of kerma-area product (PKA), fluoroscopy time (FT) and reference air-kerma (Ka,r) were recorded and correlated with PSD...
October 15, 2016: Radiation Protection Dosimetry
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"