Close contact restriction periods for patients who have received iodine-131 therapy for differentiated thyroid cancer

Patients treated with radionuclide therapy usually require restrictions on certain activities for a period of time following treatment to optimise protection of the public and ensure the legal dose limit is not exceeded. Software may be used to calculate necessary restriction periods for an individual based on longitudinal dose rate measurements from the time of radiopharmaceutical administration. A spreadsheet program has been used for this purpose in Australian hospitals for the last two decades. However, this spreadsheet has a limitation in that it uses an approximation in the calculation of dose from a contact pattern, which affects the calculated restriction period. A computer program called Dorn was developed that provides the same functionality as the spreadsheet but without this approximation. Proffered radiation safety advice from Dorn and the spreadsheet were compared. Advice from the spreadsheet and Dorn were compared for 55 patients who underwent iodine-131 therapy for differentiated thyroid cancer. The restriction periods for caring for infants, close contact with children and sleeping with a partner were typically about 13 h longer in Dorn than in the spreadsheet, but in some cases were over a week shorter or a month longer. If the Dorn program is used clinically in place of the spreadsheet, some patients will enjoy shorter restriction periods and the therapy provider can be more confident in their compliance with regulatory requirements and best practice. Dorn is freely available fromhttps://doi.org/jg5f.

Spatial resolution is dependent on image content for SPECT with iterative reconstruction incorporating distance dependent resolution (DDR) correction

The aim of this study is to determine the dependence of single photon emission computed tomography (SPECT) spatial resolution on the content of images for iterative reconstruction with distance dependent resolution (DDR) correction. An experiment was performed using a perturbation technique to measure change in resolution of line sources in simple and complex images with iterative reconstruction with increasing iteration. Projections of the line sources were reconstructed alone and again after the addition of projections of a uniform flood or a complex phantom. An alternative experiment used images of a realistic brain phantom and evaluated an effective spatial resolution by matching the images to the digital version of the phantom convolved with 3D Gaussian kernels. The experiments were performed using ordered subset expectation maximisation iterative reconstruction with and without the use of DDR correction. The results show a significant difference in reconstructed resolution between images of line sources depending on the content of the added image. The full width at half maximum of images of a line source reconstructed using DDR correction increased by 20-30 % when the added image was complex. Without DDR this difference was much smaller and disappeared with increasing iteration. Reported SPECT resolution should be taken as indicative only with regard to clinical imaging if the measurement is made using a point or line source alone and an iterative reconstruction algorithm is used.

Mental disorder and homicide: a review of epidemiological research

OBJECTIVE

This paper reviews 28 studies on the epidemiology of homicide committed by mentally disordered people, taken from recent international academic literature.

METHODS

The studies included were identified as part of a wider systematic review of the epidemiology of offending combined with mental disorder. The main databases searched were Embase, Medline, HealthStar, Psyclit, Mental Health Abstracts, Applied Social Sciences Index and Abstracts, and Criminology Penology and Police Science Abstracts. A comprehensive search was made for studies published since 1990, supplemented with key studies from the 1980s identified through citation tracing and personal contacts.

RESULTS

A summary is given in tabular form of the content and quality of each study. There is then discussion of the studies in eight categories: descriptive studies, studies of trends, comparative studies amongst homicide offenders, amongst prisoners and including general populations, studies of homicide of relatives, follow-up studies, and studies of recidivism.

CONCLUSIONS

There is an association of homicide with mental disorder, most particularly with certain manifestations of schizophrenia, antisocial personality disorder and drug or alcohol abuse. However, the quality of epidemiological research in this area is not adequate to answer key questions, and prediction of potential for homicide remains elusive. Further research is needed.

The epidemiology of mentally disordered offending: a systematic review of studies, based in the general population, of criminality combined with psychiatric illness

BACKGROUND

The international literature, from 1990 onwards, on the epidemiology of mentally disordered offending (MDO) was systematically reviewed. Studies based solely in the general population are reported in this article.

METHODS

Database searches were made back to 1990, followed by citation tracing with the authors or major publications.

RESULTS

Two cross-sectional surveys and seven cohort studies were found that have given rise to epidemiological data about MDO in the general population. The most useful data come from cohort studies in Scandinavia. In Scandinavia, the prevalence of MDO up to age 26-30 years is 2.1-2.8 per 100 for men and about half this amount for women. Conduct problems in childhood and deprivation seem to be predictors of future MDO. Mental disorder is associated with acts of crime, most particularly acts of a violent nature.

CONCLUSIONS

No systematic epidemiological study of MDO in its own right was found. Those studies which provide data on MDO generally make poor use of statistical methodology. Professional epidemiological and statistical input is required to fully exploit existing data and adequately plan future studies of MDO.

Planning to meet the needs of offenders with mental disorders in the United Kingdom

During the last decade the planning of services for offenders with mental disorders in the United Kingdom has been geared toward diverting them from the criminal justice system to appropriate levels of psychiatric and social care. Although a seamless service system is yet to be developed, the central government has made a concerted effort to promote a better understanding of the needs of offenders with mental disorders and encourage collaboration between the relevant agencies. A major program of research has been initiated, and local health authorities have been encouraged to use a consortium approach to planning and delivery of specialist services. The authors discuss the activities of the Wessex consortium, composed of five local health authorities and a social services department serving a catchment area with a population of 2.5 million in southern England. The consortium has commissioned needs assessments for all offenders with mental illness from the catchment area and a survey of the resources for secure residential treatment in the region. Based on data from this research, the consortium is planning the development of two long-stay secure units to accommodate offenders with a history of repeated inpatient and prison stays and poor response to previous treatment and rehabilitation efforts.

Reduction of thyroid hormone may participate in the modulation of cytochromes P450 2C11 and 3A2 by retinol

Both hypothyroidism and retinol supplementation in rats induce CYP 3A2 and suppress CYP 2C11. Therefore studies were performed to evaluate the role of thyroid hormones in the modulation of P450 expression by retinol. Adult male Sprague-Dawley rats were given retinol as a single oral dose of 75 mg/kg. Rats were killed and hepatic microsomes prepared at 24, 48, 72, and 96 hr following treatment. The catalytic activity of 2C11 was reduced maximally by retinol at 48 hr (by 30%) whereas 3A2 activity was elevated maximally at 24 hr (by 30%). The serum concentration of testosterone was not altered at any time point. However, retinol produced a decline in the concentration of thyroxine by 35% and 43% at 24 and 48 hr, respectively. These data suggest that administration of large doses of retinol may alter hepatic microsomal enzyme expression by perturbation of plasma thyroid hormone levels.

A peripheral vascular insufficiency test using photocell plethysmography

A preliminary laboratory study seeking an objective test for vascular insufficiency of the fingertips (Raynaud's syndrome) is described. In a limited number of subjects, circulatory changes in the vascular bed of one hand were examined by photocell plethysmography while the opposite had was immersed in ice water. The time to complete recovery after cessation of the cold stimulus was significantly longer with primary Raynaud's patients than with the control subjects (p = 0.0045). The analysis of another parameter, the relative change in pulse amplitude during cold immersion, was confounded by age and sex differences between the Raynaud's and the control group. A follow-up investigation of the application of this technique to a population of vibration-exposed chipper and grinder and control workers is in progress.