Economic Considerations for Radiation Protection in Medical Settings-Is It Time for a New Paradigm?

ABSTRACT: The full ALARA principle includes "as low as reasonably achievable" taking social and economic factors into consideration. The International Commission on Radiological Protection advises a conventional cost benefit approach (e.g., cost per monetized averted stochastic effects or years of life saved) to consider economic factors. Given small incremental radiation dose reductions to patients, workers, or the public that may be realized in medical settings and the correspondingly small changes to theoretical stochastic effects, a conventional cost benefit approach is less than ideal. This is illustrated in the case studies presented in this paper. Alternate approaches, such as cost per unit of radiation dose averted (e.g., $/µSv averted), cancer induction/fatality probabilistic thresholds, or thresholds relative to natural background radiation may be alternate options. However, the decision regarding what is a "safe" level of radiation and what are reasonable costs to make it "safer" are driven by societal values and may vary from jurisdiction to jurisdiction.

Demonstrating Compliance With Proposed Reduced Lens of Eye Dose Limits in Nuclear Medicine Settings.

Based on ongoing research on ionizing radiation thresholds for cataracts, the International Commission on Radiological Protection has proposed new guidelines lowering the annual occupational lens of eye dose limit from 150 mSv to 20 mSv. The International Atomic Energy Agency has operationalized these new guidelines. Subsequently, national/regional radiation protection regulators are reviewing their lens of eye dose limits with an aim of moving towards the proposed new limits, resulting in licensees having to demonstrate compliance. In health care settings, fluoroscopic interventional practices generally have higher lens of eye doses and nuclear medicine settings generally have lower doses. A prospective cohort (n = 19) of nuclear medicine technologists wore dedicated lens of eye dosimeters for a 3 mo period synchronized with their body dosimeter schedules. The lens of eye dosimeters were validated to have a linear response in the anticipated dose ranges. The participants worked in a relatively high-volume nuclear medicine practice, which included general and cardiac, positron emission tomography/computed tomography, radiopharmacy, and cyclotron operations. The annualized dose ranges were 0.0-3.68 mSv (lens of eye) and 0.48-4.72 mSv (whole body). There was a good correlation between lens of eye and body dosimeter readings (R = 0.67). There were no significant differences in lens of eye dose by work type, worker sex, or side on which the dosimeter was worn. The findings should be generalizable to other similar practices, especially in North America, and should be sufficient to demonstrate regulatory compliance in nuclear medicine settings with the proposed new lens of eye dose limits.

Altered [99mTc]Tc-MDP biodistribution from neutron activation sourced 99Mo.

Given potential worldwide shortages of fission sourced 99Mo/99mTc medical isotopes there is increasing interest in alternate production strategies. A neutron activated 99Mo source was utilized in a single center phase III open label study comparing 99mTc, as 99mTc Methylene Diphosphonate ([99mTc]Tc-MDP), obtained from solvent generator separation of neutron activation produced 99Mo, versus nuclear reactor produced 99Mo (e.g., fission sourced) in oncology patients for which an [99mTc]Tc-MDP bone scan would normally have been indicated. Despite the investigational [99mTc]Tc-MDP passing all standard, and above standard of care, quality assurance tests, which would normally be sufficient to allow human administration, there was altered biodistribution which could lead to erroneous clinical interpretation. The cause of the altered biodistribution remains unknown and requires further research.

Helping Health Care Providers and Clinical Scientists Understand Apparently Irrational Policy Decisions.

Health care providers (HCP) and clinical scientists (CS) are generally most comfortable using evidence-based rational decision-making models. They become very frustrated when policymakers make decisions that, on the surface, seem irrational and unreasonable. However, such decisions usually make sense when analysed properly. The goal of this paper to provide a basic theoretical understanding of major policy models, to illustrate which models are most prevalent in publicly funded health care systems, and to propose a policy analysis framework to better understand the elements that drive policy decision-making. The proposed policy framework will also assist HCP and CS achieve greater success with their own proposals.

On the significance of defective block detectors in clinical (18)F-FDG PET/CT imaging.

INTRODUCTION: Clinical positron emission tomography (PET) systems based on block detector designs suffer occasional block detector failures, which can result in patient scan cancelations. In this study, we examine the effect of defective block detectors on measurements of maximum standard uptake value (SUV(max)) and clinical image quality in 3D 2-deoxy-2-[(18)F]fluoro-D-glucose (FDG) PET/computed tomography (CT) imaging. METHODS: A Data Spectrum anthropomorphic torso phantom (4.7 kBq/ml FDG concentration, defined as SUV of 1.0) was imaged in a normally functioning Siemens Biograph 16 HiRez PET/CT scanner using a whole-body imaging protocol. Spherical lesions with SUVs ranging from 10.0 to 13.5 were placed in the phantom. Defective block detectors were simulated by zeroing the appropriate lines of response in the sinograms. Eleven one-block and seventeen two-block defect configurations were simulated in the phantom sinograms. The images were reconstructed, and the measured SUV(max) was compared with the SUV(max) for the images without detector defects. Twelve clinical PET scans were evaluated before and after simulated detector defects cases ranging from a single block up to 12 blocks (bucket). The reconstructed images were independently scored for image quality and clinical diagnosis by two nuclear physicians blinded to the presence and severity of defects in the images. RESULTS: The mean change in phantom SUV(max) was -2% (range, -6% to +3%) in the presence of a single defective block detector and -3% (range, -11% to +7%) in the presence of two defective block detectors, respectively. For the clinical patient studies, there was no significant decline in image quality score from one to two defective block detectors. In the case of 3-4 defective block detectors, image quality became marginal, and image degradation was significant with a defective bucket (12 blocks). CONCLUSION: For one or two defective block detectors in a 3D PET camera, while waiting for the repair service, routine patient scans can proceed with the proviso that the reading physician is made aware of the detector failure.

The effect of furosemide dose timing on bladder activity in oncology imaging with 18F-fluorodeoxyglucose PET/CT.

OBJECTIVE: To compare the effects of two furosemide administration protocols on bladder activity during 18F-fluorodeoxyglucose (18F-FDG) PET/computed tomography (CT) imaging. METHODS: A total of 109 consecutive patients with known or suspected malignancy, meeting our inclusion criteria, were chosen over a discrete time period. Group 1 (n=39) received furosemide 20 mg intravenous 15 min before PET/CT imaging (i.e. approximately 45 min after 18F-FDG administration). Group 2 (n=45) received furosemide 20 mg intravenous 15 min after 18F-FDG. Group 3 (n=25) did not receive furosemide and served as controls. Bladder standard uptake values (SUVs) and volume, and liver SUV data were collected. RESULTS: Relative to the control group, both furosemide groups showed significantly lower mean and maximum SUV bladder activities (P<0.001), lower mean bladder-to-liver SUV ratios (P<0.001), larger mean bladder volumes (P<0.001) and higher proportions of bladder PET/CT image mis-registration. Patients tolerated earlier administration of furosemide (group 2) better relative to urinary urgency during imaging. CONCLUSION: The use of a relatively simple diuretic protocol can significantly lower bladder FDG activity and potentially improve image quality by reducing bladder activity artifacts and avoid invasive bladder catheterization. Administering furosemide earlier after FDG injection (i.e. 15 min) versus later (i.e. 15 min before imaging) appears to be better tolerated by patients.

Practical Aspects of 18F-FDG PET When Receiving 18F-FDG from a Distant Supplier.

UNLABELLED: With PET becoming more widely used, there is an increase in the number of imaging centers being forced to rely on distant suppliers of (18)F-FDG. Because of the large distances between major urban centers, this is particularly true for PET centers in Canada. METHODS: Our PET center, located in Winnipeg, Manitoba, Canada, currently purchases (18)F-FDG from a commercial vendor located more than 1,000 km from Winnipeg, necessitating transport by commercial airline cargo. This dependence on air transport and a distant supplier creates a situation in which our (18)F-FDG supply is less reliable than it would be with onsite production. In this article, we offer insight into the obstacles we have encountered in imaging with a distant supplier of (18)F-FDG and the solutions we have implemented to minimize the disruption to our patients and maximize the number of scans performed each year. RESULTS: The development of contingency plans and protocols designed to suit our operating environment has allowed us to increase the number of patient scans obtained from 659 in year 1 to 993 in year 3, an increase of 51%, despite an increase in our actual number of scan days of only 24%. (18)F-FDG injection timetables are presented for a variety of scenarios including normal delivery, low shipped activity, and delayed delivery. CONCLUSION: Through the careful establishment of contingency protocols and management of (18)F-FDG shipments, patient throughput can be increased and disruptions minimized.

The cost of lung cancer in Alberta.

BACKGROUND: Lung cancer is the leading cause of cancer morbidity and mortality. In addition, lung cancer has a significant economic impact on society. OBJECTIVE: To present an economic analysis of the actual care costs of lung cancer which will allow comparison with, and verification of, cost estimates that were developed through modelling and opinion. METHODS: A chart review was conducted of incident cases (circa 1998) of primary bronchogenic lung cancer. Cases were censored at two years from the date of diagnosis. Relevant clinical and health utilization data were collected. Health utilization data included hospital and institutional outpatient (ie, ambulatory clinic) costs. Cost estimates were derived for over 200 specific health services. The present analysis was performed from the economic perspective of the health care institution. RESULTS: A total of 13,389 health service events were captured with an estimated total cost of $8.4 million. Laboratory tests, diagnostic imaging and ambulatory visits constituted 86% of the service events while patient admissions and therapy constituted 76% of the costs. The vast majority of overall costs occurred just before, or within, three months of diagnosis. The median nonsmall cell lung cancer and small cell lung cancer case costs were $10,928 (range $9,234 to $11,047) and $15,350 (range $13,033 to $21,436), respectively. CONCLUSION: The results agree with the literature that the majority of lung cancer case costs are realized around the date of diagnosis (ie, early phase). The present study illustrates Canadian health care system lung cancer case costs based on actual care received versus hypothetical care algorithms.

Variation in heart rate influences the assessment of transient ischemic dilation in myocardial perfusion scintigraphy.

BACKGROUND: Transient arrhythmias can affect transient ischemic dilation (TID) ratios. This study was initiated to evaluate the frequency and effect of normal heart rate change on TID measures in routine clinical practice. METHODS: Consecutive patients undergoing stress/rest sestamibi gated myocardial perfusion scintigraphy were studied (N = 407). Heart rate at the time of stress and rest imaging were recorded. TID ratios were analyzed in relation to absolute change in heart rate (stress minus rest) for subjects with normal perfusion and systolic function (Group 1, N = 169) and those with abnormalities in perfusion and/or function (Group 2, N = 238). RESULTS: In Group 1, mean TID ratio was inversely correlated with the change in heart rate (r = -0.47, P < 0.0001). For every increase of 10 BPM in heart rate change, the TID ratio decreased by approximately 0.06 (95% confidence interval 0.04-0.07). In Group 2, multiple linear regression demonstrated that the change in heart rate (beta = -0.25, P < 0.0001) and the summed difference score (beta = 0.36, P < 0.0001) were independent predictors of the TID ratio. CONCLUSION: Normal variation in heart rate between the stress and rest components of myocardial perfusion scans is common and can influence TID ratios in patients with normal and abnormal cardiac scans.

Public investment in providing information for chronic disease prevention for adults in Alberta.

BACKGROUND: The World Health Organization in 2000 cited specific chronic diseases (chronic obstructive pulmonary disease, heart disease, diabetes and certain cancers) as major and preventable health hazards. There have subsequently been calls for increased investment in prevention activities. Currently there is no information on the economic magnitude of these promotion activities. In this study, we present an estimate of the investment in Alberta, by public organization, for chronic disease prevention activities which provide information that promotes behaviour changes in adults at risk. METHODS: We surveyed board members of the Alberta Healthy Living Network (AHLN) to obtain economic data and information on activities related to chronic disease (primary) prevention. We also asked for further contacts on programs in other agencies. We continued the ("snowball") process until no new agencies were identified. Agencies provided the information on a survey form. RESULTS: In 2003 in Alberta, the cost of publicly provided information to change risk behaviours related to chronic diseases for persons over 20 was dollars 24.9 million. This investment was diffused over a large number of bodies. Anti-smoking programs used the largest proportion of the money. The total cost per person at risk was about dollars 15. Regional Health Authorities spend about 1/10th of 1% of their budget on these activities. DISCUSSION: There are difficulties in collecting and organizing society-level data on chronic disease prevention. Nevertheless, all indications are that the amount of resources devoted in this area is small, and much smaller than has been suggested.

A population-based analysis of health behaviours, chronic diseases and associated costs.

Health behaviours influence the future incidence of certain common chronic diseases and thus have an impact on health status and utilization of health care services and costs. We analyzed person-level data of the Albertan adult population from the Canadian Community Health Survey, Cycle 1.1 (2000) to determine health care costs associated with specific health behaviours (smoking, sub-optimal diet, physical inactivity) and chronic disease states (heart disease, diabetes, COPD). We found that 74.7 percent of the population exhibited one or more risk behaviours, while 10.5 percent had one or more of the chronic diseases of interest. Greater health care utilization and costs were noted in groups exhibiting risk behaviour and chronic disease states. Approximately 31 percent of health care costs in Alberta were attributable to people having one or more of the three chronic diseases. Our findings of higher health care costs incurred by those exhibiting unhealthy behaviour prior to development of disease, as well as by those with multiple co-existent diseases, are important indicators to guide future prevention and treatment strategies of chronic illness.

Socioeconomic status and the utilization of diagnostic imaging in an urban setting.

BACKGROUND: In publicly funded health care systems, the utilization of health care services should be equitable, irrespective of socioeconomic status (SES). Although the association between SES and health care utilization has been examined in Canada relative to surgical, cardiac and preventive health care services, no published studies have specifically explored the association between SES and diagnostic imaging. METHODS: We examined over 300,000 diagnostic imaging claims made in the Winnipeg Regional Health Authority between Apr. 1, 2001, and Mar. 31, 2002. Using patient postal codes, we assigned SES on the basis of average household incomes in Canada's 1996 census. Using multiple regression, we examined the association between income quintile, patient age group (< or =16, 17-64, > or = 65 years), patient morbidity level according to the Johns Hopkins University Adjusted Clinical Group method (high, moderate, low), and imaging modality (general radiology, vascular, computed tomography, magnetic resonance, and general and obstetric ultrasound). RESULTS: Relative rates (RR) of diagnostic imaging utilization (highest v. lowest income quintile) were significantly increased in pediatric and adult patient groups at all morbidity levels receiving general radiology (highest RR 2.47, 95% confidence interval [CI] 2.07-2.93); pediatric and adult patient groups at high and low morbidity levels and elderly patient groups at low morbidity levels receiving general ultrasound (highest RR 2.26, 95% CI 1.20-4.26); pediatric and adult patient groups at all morbidity levels and elderly patients at high and moderate morbidity levels receiving magnetic resonance imaging (highest RR 2.51, 95% CI 1.78- 3.52); and adult patient groups at all morbidity levels receiving computed tomography (highest RR 1.46, 95% CI 1.35- 1.59). A lower RR of diagnostic imaging utilization in the highest income quintile was found only among patients receiving obstetric ultrasound (RR 0.80, 95% CI 0.73-0.87). No significant associations were found among elderly patients receiving general radiology or computed tomography or adult patients receiving vascular imaging. INTERPRETATION: We found a pattern of increased diagnostic imaging utilization in patient groups with a higher SES. Further research is needed to better understand the nature of this finding and how it contributes to health outcomes.

Radioactive iodine therapy for malignant and benign thyroid disease: a Canadian national survey of physician practice.

BACKGROUND: Radioactive iodine (as Na131I) has been used in the diagnosis and treatment of thyroid disease for more than 60 years, but the various treatment centres in Canada have different practice patterns. AIM: To determine whether there is a definable, nationwide pattern of practice which may be used to elucidate standards of practice and clarify some issues that arise when multiple care-givers are involved. METHODS: A survey questionnaire was mailed to all sites licensed by the Canadian Nuclear Safety Commission to administer Na131I for benign and malignant thyroid therapy. A second mailing was sent to non-responders. The questionnaire addressed the involvement of personnel: i.e., who prescribes, determines doses, obtains informed consent, counsels on radiation safety, administers the therapy, and follows the patient post-therapy. The survey also specifically addressed whether a nuclear medicine physician reviewed laboratory work or met with patients pre-therapy. RESULTS: The overall response rate was 60% (74/123) with representation from all Canadian provinces. The majority of respondents were physicians (78%). The data include 3447 benign thyroid therapies and 1202 malignant thyroid therapies. There are no significant regional differences in the average maximum dose administered for either benign or malignant thyroid therapies. The majority of therapies are administered in community and academic hospital settings. Endocrinologists most commonly prescribe Na131I for malignant thyroid therapies and nuclear medicine physicians for benign thyroid therapies. For all therapies nuclear medicine physicians most commonly obtain informed consent, determine the dose and provide radiation safety counselling. Nuclear medicine technologists most commonly administer the therapy and endocrinologists most commonly provide post-therapy follow-up. In the majority of centres, nuclear medicine physicians review the laboratory results for each patient's blood sample and meet with patients before therapy. CONCLUSIONS: Multiple health care specialists take part in Na131I therapy for both benign and malignant thyroid disease. In most centres, nuclear medicine physicians have major roles in the delivery of the treatments, including reviewing clinical and biochemical information. The findings of this study should provide reassurance to many centres and guidance to others to allow closer harmonization of practice.

The descriptive epidemiology of primary lung cancer in an Alberta cohort with a multivariate analysis of survival to two years.

BACKGROUND: Lung cancer contributes significantly to cancer morbidity and mortality. Although case fatality rates have not changed significantly over the past few decades, there have been advances in the diagnosis, staging and management of lung cancer. OBJECTIVE: To describe the epidemiology of primary lung cancer in an Alberta cohort with an analysis of factors contributing to survival to two years. PATIENTS AND METHODS: Six hundred eleven Albertans diagnosed with primary lung cancer in 1998 were identified through the Alberta Cancer Registry. Through a chart review, demographic and clinical data were collected for a period of up to two years from the date of diagnosis. RESULTS: The mean age at diagnosis was 66.5 years. The majority of cases (92%) were smokers. Adenocarcinoma, followed by squamous cell carcinoma, were the most frequent nonsmall cell lung cancer histologies. Adenocarcinoma was more frequent in women, and squamous cell carcinoma was more frequent in men. The overall two- year survival rates for nonsmall cell, small cell and other lung cancers were 24%, 10% and 13%, respectively. In multivariate analysis, stage, thoracic surgery and chemotherapy were significantly associated with survival to two years in nonsmall cell carcinoma; only stage and chemotherapy were significant in small cell carcinoma. CONCLUSIONS: This study provides a Canadian epidemiological perspective, which generally concurs with the North American literature. Continued monitoring of the epidemiology of lung cancer is essential to evaluate the impact of advances in the diagnosis, staging and management of lung cancer. Further clinical and economic analysis, based on data collected on this cohort, is planned.