Mortality after cerebral angiography with or without radioactive Thorotrast: an international cohort of 3,143 two-year survivors.

There are few studies on the long-term sequelae of radionuclides ingested or injected into the human body. Patients exposed to radioactive Thorotrast in the 1930s through the early 1950s provide a singular opportunity, since the administration of this radiographic contrast agent resulted in continuous exposure to alpha particles throughout life at a low dose rate. We evaluated cause-specific mortality among an international cohort of 3,143 patients injected during cerebral angiography with either Thorotrast (n = 1,736) or a similar but nonradioactive agent (n = 1,407) and who survived 2 or more years. Standardized mortality ratios (SMRs) for Thorotrast and comparison patients were calculated, and relative risks (RR), adjusted for population, age and sex, were obtained by multivariate statistical modeling. Most patients were followed until death, with only 94 (5.4%) of the Thorotrast patients known to be alive at the closure of the study. All-cause mortality (n = 1,599 deaths) was significantly elevated among Thorotrast subjects [RR 1.7; 95% confidence interval (CI) 1.5-1.8]. Significantly increased relative risks were found for several categories, including cancer (RR 2.8), benign and unspecified tumors (RR 1.5), benign blood diseases (RR 7.1), and benign liver disorders (RR 6.5). Nonsignificant increases were seen for respiratory disease (RR 1.4) and other types of digestive disease (RR 1.6). The relative risk due to all causes increased steadily after angiography to reach a threefold RR at 40 or more years (P < 0.001). Excess cancer deaths were observed for each decade after Thorotrast injection, even after 50 years (SMR 8.6; P < 0.05). Increasing cumulative dose of radiation was directly associated with death due to all causes combined, cancer, respiratory disease, benign liver disease, and other types of digestive disease. Our study confirms the relationship between Thorotrast and increased mortality due to cancer, benign liver disease, and benign hematological disease, and suggests a possible relationship with respiratory disorders and other types of digestive disease. The cumulative excess risk of cancer death remained high up to 50 years after injection with >20 ml Thorotrast and approached 50%.

Chromosomal aberrations and hprt mutant frequencies in long-term American thorotrast survivors.

PURPOSE: Patients injected with thorotrast, a radiologic contrast medium used from the 1920s to early 1950s, received chronic internal exposure to thorium-232, an alpha-emitter. Epidemiologic studies have observed markedly elevated risks of death from hepatic and hematologic cancers and extensive chromosomal damage among these patients. Few investigations have correlated multiple measures of genetic damage to determine whether these have independent induction kinetics. The distribution of chromosomal aberrations (CA) and mutant frequencies (MF) at the hypoxanthine phosphoribosyltransferase (hprt) locus was evaluated in eight long-term thorotrast survivors (mean exposure time=47.4 years) and five individuals who received a nonradioactive contrast medium during the same era. MATERIALS AND METHODS: Peripheral blood lymphocytes were harvested from whole blood, CA were scored in 500 complete metaphases and a clonal assay was used to determine hprt MF. Symmetrical aberrations were not evaluated. Differences in frequencies and correlations between endpoints were assessed using nonparametric methods. RESULTS: Thorotrast-exposed individuals differed from the comparison group in total number of multicentrics and centric and acentric rings (per 500 cells [median, mean +/- sd]: 11, 18.3+/-23.1 vs 2, 2.4+/-1.1, p =0.04). There was no difference between the groups on hprt MF (12.6, 15.9+/-13.5 vs 16.6, 14.0+/-8.8[ x 10(-6)]; p= 1.0). Among the exposed, hprt MF was moderately correlated with the frequency of asymmetrical chromosomal aberrations, although the association was not statistically significant. CONCLUSION: Noting the limitations of small samples, long-term thorotrast survivors were observed to be at an increased risk for genetic damage.

The impact of routine chest radiography on ICU management decisions: an observational study.

OBJECTIVE: To document the impact of routine daily chest radiographs on treatment decisions in a medical ICU. METHODS: The study sample consisted of 200 consecutive patients in an 11-bed medical ICU of a university-affiliated teaching hospital. During the study period, each patient's current and previous chest radiographs were reviewed in the ICU during morning rounds. A computerized digital video display system was used. Changes in therapy made as a consequence of this review were recorded. RESULTS: A total of 471 chest radiographs were reviewed. The patients' mean score on the Acute Physiology and Chronic Health Evaluation II (APACHE II) was 14.6 +/- 2.5, and the mean length of stay in the ICU was 3.6 days +/- 2.1 days (range, 11-24 days). A change in therapy was made on the basis of information obtained from review of the chest radiograph in 174 instances (37% of radiographs). The most frequent therapeutic interventions were use of a loop diuretic to treat pulmonary edema (26%), repositioning of an endotracheal tube (24%), and diagnostic studies to determine the cause of a new pulmonary infiltrate (16%). At least one change in therapy was made for 91 (66%) of the 138 intubated patients but for only 14 (23%) of the 62 nonintubated patients; this difference was significant. Differences among diagnostic groups were largely a reflection of the number of patients who were intubated. CONCLUSION: Routine daily chest radiographs may be justified in critically ill patients in a medical ICU because for a large proportion of these patients management decisions are made on the basis of information obtained from the chest radiograph. This observation may be applicable only to ICUs that have a high turnover of patients who are in the unit for a short time.

Too many radiologists? Update.

In light of the growing concern that a large surplus of diagnostic radiologists is pending, the authors (a) reviewed the major projections of the surplus-shortage situation made during the past quarter century and (b) semiquantitatively analyzed factors widely expected to have a substantial effect on the future situation. Projections uniformly were seriously mistaken. Some factors expected to affect the future, such as the increasing percentage of women among radiologists, are foreseeable and have small effects. However, other factors, most notably new technology, cannot be predicted, although their effects may be very large. The authors conclude that the long-term future situation is not predictable. The authors also examined steps that might be taken to reduce the supply of radiologists if a large surplus were known to be pending and antitrust prohibitions against coordinated responses were eliminated. At first, there appear to be multiple actions possible that would reduce the number of graduates of residency programs while preserving, or even enhancing, quality and equity. Closer examination, however, shows that these actions are often conflicting, sometimes not actually desirable, and generally troubled by questions of effectiveness and feasibility of implementation. Thus, even with changes in the law, the authors find no ready solutions to a possible large oversupply of radiologists.

The employment market for 1995 graduates of diagnostic radiology and radiation oncology training.

OBJECTIVE: Despite widespread concern that a major surplus of non-primary-care physicians is developing, little nonanecdotal information has been available. Therefore, we developed and applied a methodology for appraising the situation of new graduates. Graduates should be particularly vulnerable because, unlike seasoned physicians. they all must find employment. MATERIALS AND METHODS: In April-May 1995, and in a December follow-up, we surveyed diagnostic radiology and radiation oncology training program directors about the status of their 1995 residency and fellowship graduates, their programs, and the employment market. More than 90% responded. We compared findings with similar 1994 surveys. Differences were assessed with t tests or multiple regression analyses, with a p value of less than or equal to .05 as the test of significance. RESULTS: Directors reported unemployment 6 months after graduation was 0.6% (+/- 0.3%) for diagnostic radiology fellows and less for others. They said approximately 90% of graduates had positions reasonably matching their training and personal employment goals. Reported unemployment rates and percentages of graduates in desired positions did not differ from 1994. However, training directors generally were more pessimistic in 1995, overwhelmingly reporting the employment market was more difficult than in recent years. Few statistically significant differences among subgroups--including diagnostic subspecialties--were found. Net planned changes in program size will generate reductions of at most a few percent in the annual number of graduates, and more than 98% of beginning year residency slots were filled. CONCLUSION: Unemployment was remarkably low. Also, surprisingly, even "soft" indicators such as undesired positions or difficulties during the process of employment search (i.e., in April-May) did not show deterioration. Projections of pending physician surpluses may be exaggerated. Given our findings, program directors' growing pessimism is puzzling. This pessimism has not called forth sizable cuts in program size and, if major surpluses are pending, neither reductions in program size nor failure to fill all available slots offer significant relief, at least to date. The employment market is about equally good (or equally difficult) across diagnostic subspecialties. The absence of regional differences indicates graduates are effectively reaching beyond the locality where they trained in their employment search.

Diaphragm levels as determinants of P axis in restrictive vs obstructive pulmonary disease.

BACKGROUND AND OBJECTIVE: Verticalized P axes in adults with obstructive lung disease have long been appreciated as characteristic of emphysema. After demonstrating P axes in restrictive lung disease to have a significantly different orientation (intermediate to horizontal), it was hypothesized that opposite effects on diaphragm level by obstructive disease (low diaphragm) and by restrictive disease (high diaphragm) could explain the axis differences, because the right atrium is attached via the inferior vena cava and adjacent pericardium to the right leaf of the diaphragm. METHODS: Electrocardiograms and chest radiographs were analyzed independently in a new series of 20 consecutive patients with purely obstructive and 19 consecutive patients with purely restrictive pulmonary disease. P axes were calculated to the nearest 5 degrees and grouped as vertical (+65 degrees to +90 degrees), intermediate (+40 degrees to +60 degrees), and horizontal (< +50 degrees). Chest radiographs established the right diaphragmatic level by posterior rib number or interspace with interspaces designated as "0.5" plus the number of the rib above. RESULTS: P axes for obstructive vs restrictive disease were different (p < 0.001) as in our previous investigation. In the present series, 19 of 20 electrocardiograms in patients with obstructive disease had vertical P axes between +70 degrees and +90 degrees; in 11 of 19 patients with restrictive disease, P axes were less than +40 degrees (horizontal); 6 were between +40 degrees and +60 degrees (intermediate); and only 2 were vertical. Diaphragm levels were between rib/interspace numbers 10.5 and 12.5 in all patients with obstructive disease. Diaphragm levels among patients with restrictive disease were higher and, like their P axes, more widely distributed: 10 of 19 between rib levels 8.0 and 9.5; only 4 at 10.5 or lower. Thus, vertical P axes corresponded to low (rib/interspace 10.5 to 12.5) and intermediate to horizontal P axes with higher (8.0 to 11.0 rib) diaphragm levels (p < 0.001). CONCLUSION: Because the separate P-axis distributions in restrictive and obstructive lung disease parallel the separate diaphragm levels and because the right atrium is necessarily carried by attachments to the right diaphragmatic leaf, it is likely that the consequent positional effects on the right atrium contribute to or cause the significantly different P-axis orientations in restrictive and obstructive pulmonary disease.