PubMed Health⌕ Search

Biomedical subjects

Kenneth Roberts

Publications and source records attributed to Kenneth Roberts.

7 recordsLinked to original sources
PubMed2006

Development of a statewide hospital plan for radiologic emergencies.

Although general guidelines have been developed for triage of victims in the field and for hospitals to plan for a radiologic event, specific information for clinicians and administrators is not available for guidance in efficient management of radiation victims during their early encounter in the hospital. A consensus document was developed by staff members of four Connecticut hospitals, two institutions of higher learning, and the State of Connecticut Department of Environmental Protection and Office of Emergency Preparedness, with assistance of the American Society for Therapeutic Radiology and Oncology. The objective was to write a practical manual for clinicians (including radiation oncologists, emergency room physicians, and nursing staff), hospital administrators, radiation safety officers, and other individuals knowledgeable in radiation monitoring that would be useful for evaluation and management of radiation injury. The rationale for and process by which the radiation response plan was developed and implemented in the State of Connecticut are reviewed. Hospital admission pathways are described, based on classification of victims as exposed, contaminated, and/or physically injured. This manual will be of value to those involved in planning the health care response to a radiologic event.

Connecticut↗
PubMed2006

Potential impact of prostate edema on the dosimetry of permanent seed implants using the new 131Cs (model CS-1) seeds.

Our aim in this work was to study the potential dosimetric effect of prostate edema on the accuracy of conventional pre- and post-implant dosimetry for prostate seed implants using the newly introduced 131Cs seed, whose radioactive decay half-life (approximately 9.7 days) is directly comparable to the average edema resolution half-life (approximately 10 days) observed previously by Waterman et al. for 125I implants [Int. J. Radiat. Oncol. Biol. Phys. 41, 1069-1077 (1998)]. A systematic calculation of the relative dosimetry effect of prostate edema on the 131Cs implant was performed by using an analytic solution obtained previously [Int. J. Radiat. Oncol. Biol. Phys. 47, 1405-1419 (2000)]. It was found that conventional preimplant dosimetry always overestimates the true delivered dose as it ignores the temporary increase of the interseed distance caused by edema. The overestimation for 131Cs implants ranged from 1.2% (for a small edema with a magnitude of 10% and a half-life of 2 days) to approximately 45% (for larger degree edema with a magnitude of 100% and a half-life of 25 days). The magnitude of pre- and post-implant dosimetry error for 131Cs implants was found to be similar to that of 103Pd implants for typical edema characteristics (magnitude < 100%, and half-life <25 days); both of which are worse compared to 125I implants. The preimplant dosimetry error for 131Cs implants cannot be compensated effectively without knowing the edema characteristics before the seed implantation. On the other hand, the error resulted from a conventional post-implant dosimetry can be minimized (to within +/-6%) for 131Cs implants if the post-implant dosimetry is performed at 10+/-2 days post seed implantation. This "optimum" post-implant dosimetry time is shorter than those determined previously for the 103Pd and 125I implants at 16+/-4 days and 6+/-1 weeks, respectively.

Brachytherapy↗
PubMed2006

Hypnosis in dentistry.

UNLABELLED: In this article, the nature of hypnosis will be discussed, together with its therapeutic/facilitator role in the control of the potential problems that occur in everyday dental practice. It is the vital relationship between a patient and therapist which produces the desired results of hypnotherapy. CLINICAL RELEVANCE: A holistic approach, in patient care, emphasizes the treatment of an individual who has a dental problem.

Blood Loss, Surgical↗
PubMed2003

Falciparum malaria: an outbreak in a military population on an operational deployment.

BACKGROUND: In May 2000, the United Kingdom deployed a joint force to Sierra Leone on an operation covering four phases. Each phase was characterized by high exposure risk of falciparum malaria but with varying risks due to the combat environment that affected implementation of malarial protection policy. AIM: This study will describe the risks managed concerning malarial protection for the force and match these to the attack rates (AR) suffered by the force. METHODS: The evidence concerning current malarial protection will be revisited. The risks attributable to disease and combat environment will be described and AR calculated using disease notifications as the numerator and operational personnel returns as the denominator. RESULTS: ARs appeared to be higher where the risk of hostile activity was higher. The evidence base concerning the use of malarial protection measures remains valid. The AR associated with deployment of a force to a high malaria risk area with a high associated risk of hostile action appears to be 0.78 cases per person-years exposure. The AR for personnel deployed to a high malaria risk area with a low risk of hostile action appears to be 0.078 cases per person-years exposure.

Adult↗
PubMedDate not supplied

Effects of vessel curvature on dose distributions in catheter-based intravascular brachytherapy for various radionuclides.

PURPOSE: When radioactive sources are used to treat restenosis, the blood vessels are usually curved. In catheter-based intravascular brachytherapy systems, this curvature introduces dose deviations from the idealized situation used for treatment planning, in which both blood vessels and sources are assumed to be straight. Because of the different depth characteristics of different radionuclides, it is foreseeable that the curvature effects on dosimetry might vary with the different types of radionuclides. In this study, curvature effects on dose distributions along and around a blood vessel were investigated for different gamma and beta emitters. MATERIALS/METHODS: A blood vessel was modeled as a cylinder that could be curved as a circular arc of different degrees. Dose calculations were performed on the cylindrical surfaces of the model vessel for the radioactive sources of (192)Ir, (125)I, (103)Pd, (188)Re, (32)P, and (90)Y/Sr. The radius of the vessel was assumed to be 1.0, 1.5, 2.0, and 2.5 mm, respectively. A catheter-based radiation delivery system was simulated to consist of a line source with a length of 2 cm. The dose rate at a point in space produced by the radioactive source was computed by integrating the point dose rate kernel of the corresponding radionuclide over the entire radioactive line, which was assumed to curve with the blood vessel along its central axis. Dosimetric calculations were performed for different curvature angles. The curvature effects on the dosimetry were characterized with two quantities, LDU and ADU, where LDU described the longitudinal dose uniformity (LDU) along blood vessels and ADU described the azimuthal dose uniformity (ADU) from the expected delivery dose around blood vessels. RESULTS: Vessel and source curvatures barely changed the LDU for the gamma emitters (within 2%). The curvature effects on the LDU were relatively larger for the beta emitters (less than 5%). The dose deviations caused by curvature around a blood vessel were more significant. Depending on the radius of the vessel and degree of curvature, the deviation could be as much as 25% for the gamma emitters and 30% for the beta emitters. The curvature effects became larger with the increase of vessel radius and, obviously, with the increase of curvature. There seemed to be no significant differences in the curvature effects among different types of gamma emitters and among different types of beta emitters. CONCLUSIONS: Curvature-induced effects on dose distribution are similar for both the gamma and the beta emitters. The LDU along the vessels does not change significantly with curvature. The dose changes around the vessels are more pronounced and can be as high as 30%.

Blood Vessels↗
PubMedDate not supplied

Managing the microbiological risks of drinking water.

The microbiological contamination of drinking water supplies can have serious health consequences for consumers, and this has been dramatically illustrated in recent years by two disease outbreaks in Canada. In this paper, some factors that can influence the microbiological quality of drinking water and its management are examined. Frameworks have been proposed that help to clarify the main elements of health risk assessment and risk management, and, in accordance with these, risks can be logically characterized, evaluated and controlled. A protocol has been developed for microbiological risk assessment and a risk management framework now guides the development of Canada's national guidelines for drinking-water quality. Monitoring of indicator organisms and the application of adequate water treatment are the primary means recommended in the Canadian guidelines to safeguard health from the presence of water-borne pathogens. Understanding the biological characteristics of microbial pathogens is necessary for assessing their impact on community health and appraising the rationale behind drinking-water testing methods and their limitations. Improvements in health surveillance, monitoring, and risk characterization and application of concepts such as multiple barriers (source-to-tap) and total quality management should contribute to better management of the microbiological quality of drinking water.

Canada↗