An alternative diagnostic strategy with lower radiatioin risk in young women with suspected pulmonary embolism

Background: Since younger women have an increased risk of cancer following radiation exposure with CT scanning, they might benefit from an alternative diagnostic strategy for suspected pulmonary embolism (PE).Methods: We investigated the safety and efficiency of a diagnostic strategy consisting of clinical probability, D-dimer testing, chest X-ray and perfusion-scintigraphy in women aged <50 years with suspected PE, in order to reduce the number of CT scans. This strategy was retrospectively analyzed in two cohorts of consecutive patients with suspected PE, in which perfusion scans and chest X- rays were combined (X/Q-scan). X/Q-scans were re-evaluated in the second cohort. We calculated the predictive accuracy and the proportion of women in whom CT could be avoided. Results: A total of 236 women <50 years with suspected PE were included. The prevalence of PE was 20% and 19% for the first and second cohort, respectively. PE was excluded in 51% (81/159) and 32% (25/77) based on an unlikely Wells score combined with a normal D-dimer test. In the remaining women in the first cohort, 44% (95%CI, 33-55%) had a normal X/Q-scan; 40% (CI 30-51%) had a non-high X/Q-scan and 14% (CI 8-24%) a high-probability X/Q-scan. In the second cohort, these percentages were 58% (44-70%), 17% (9-30%) and 25% (CI 15-38%), respectively. The positive predictive value of a high probability X/Q-scan was high in both cohorts: 82% (95%CI, 52-95%) and 100% (CI 77-100%), respectively. CT could theoretically be avoided in 60% and 83% (CI 70-91%) of women. Conclusion: A diagnostic strategy consisting of clinical decision rule, D-dimer testing, perfusion scintigraphy and chest X-ray appears to be promising to reliably exclude or diagnose PE in young women, without the need for CT-scanning. Further prospective evaluation in a larger population of young women is warranted.