[Radiation exposure of radiologists during angiography: dose measurements outside the lead apron]

Personal dosimetry for interventional operators: when and how should monitoring be done?

OBJECTIVE

Assessment of the potential doses to the hands and eyes for interventional radiologists and cardiologists can be difficult. A review of studies of doses to interventional operators reported in the literature has been undertaken.

METHODS

Distributions for staff dose to relevant parts of the body per unit dose-area product and for doses per procedure in cardiology have been analysed and mean, median and quartile values derived. The possibility of using these data to provide guidance for estimation of likely dose levels is considered.

RESULTS

Dose indicator values that could be used to predict orders of magnitude of doses to the eye, thyroid and hands from interventional operator workloads have been derived, based on the third quartile values, from the distributions of dose results analysed.

CONCLUSION

Dose estimates made in this way could be employed in risk assessments when reviewing protection and monitoring requirements. Data on the protection provided by different shielding and technique factors have also been reviewed to provide information for risk assessments. Recommendations on the positions in which dosemeters are worn should also be included in risk assessments, as dose measurements from suboptimal dosemeter use can be misleading.

Effect of a one-session versus two-session procedure on different parameters of interventional therapy for peripheral arterial occlusive disease: results of a retrospective cohort study

PURPOSE

To compare the effects of a one-session procedure (ie, diagnostic angiography immediately followed by intervention) versus a two-session procedure (ie, diagnostic angiography and intervention in two separate sessions) on interventional therapy in patients with peripheral arterial occlusive disease (PAOD).

MATERIALS AND METHODS

Interventional therapy was performed immediately after diagnostic angiography in one session in 228 patients (group 1) and in a chronologically separate, later session in another 43 patients (group 2). The retrospectively captured parameters were Fontaine stage, TransAtlantic InterSociety Consensus II criteria, angiographic severity, type, technical success and complication rates, examination times, volume of contrast media, radiation exposure, and fluoroscopy time for intervention.

RESULTS

There were no between-group differences in clinical and interventional parameters. In group 1 there were 340 interventions performed, and there were 61 in group 2 with an interval before intervention of 1-55 days. The groups showed comparable success rates (92.6% vs 91.8%; P = .79) and complication rates (5.7% vs 4.65%; P = 1.0). The examination times were similar at 82.6 minutes +/- 40.5 and 91.3 minutes +/- 69.9, respectively (P = .92). Volume of contrast media (301.7 mL +/- 81.3 vs 459.2 mL +/- 123.7) and radiation exposure (140.5 Gy/cm(2) +/- 152.1 vs 304.7 Gy/cm(2) +/- 217.4) were significantly lower in group 1 (P < .001 each). Fluoroscopy times trended lower in group 1.

CONCLUSIONS

In patients with PAOD, interventional therapy of iliac and femoropopliteal artery lesions performed in the same session as diagnostic angiography yields technical success and complication rates comparable to those seen with a two-session procedure, but is associated with significantly less contrast media use and radiation exposure.

A review of radiology staff doses and dose monitoring requirements

Studies of radiation doses received during X-ray procedures by radiology, cardiology and other clinical staff have been reviewed. Data for effective dose (E), and doses to the eyes, thyroid, hands and legs have been analysed. These data have been supplemented with local measurements to determine the most exposed part of the hand for monitoring purposes. There are ranges of 60-100 in doses to individual tissues reported in the literature for similar procedures at different centres. While ranges in the doses per unit dose-area product (DAP) are between 10 and 25, large variations in dose result from differences in the sensitivity of the X-ray equipment, the type of procedure and the operator technique, but protection factors are important in maintaining dose levels as low as possible. The influence of shielding devices is significant for determining the dose to the eyes and thyroid, and the position of the operator, which depends on the procedure, is the most significant factor determining doses to the hands. A second body dosemeter worn at the level of the collar is recommended for operators with high workloads for use in assessment of effective dose and the dose to the eye. It is proposed that the third quartile values from the distributions of dose per unit DAP identified in the review might be employed in predicting the orders of magnitude of doses to the eye, thyroid and hands, based on interventional operator workloads. Such dose estimates could be employed in risk assessments when reviewing protection and monitoring requirements. A dosemeter worn on the little finger of the hand nearest to the X-ray tube is recommended for monitoring the hand.