Effective dose and effective risk from post-SPECT imaging of the lumbar spine

Tootell, AK; McEntee, MF; Szczepura, K; Hogg, P

Abstract

Purpose
Planar bone scans play an important role in the staging and monitoring of malignancy and metastases. Metastases in the lumbar spine are associated with significant morbidity, therefore accurate diagnosis is essential. Supplementary imaging after planar bone scans is often, required to characterise lesions, however, this is associated with additional radiation dose. This paper provides information on the comparative effective dose and effective risk from supplementary lumbar spine radiographs, low-dose CT (LDCT) and diagnostic CT (DCT).
Method
Organ dose was measured in a phantom using thermo-luminescent dosimeters. Effective dose and effective risk were calculated for radiographs, LDCT, and DCT imaging of the lumbar spine.
Results
Radiation dose was 0.56mSv for the antero-posterior and lateral lumbar spine radiographs, 0.80mSv for LDCT, and 3.78mSv for DCT. Additional imaging resulted in an increase in effective dose of 12.28%, 17.54% and 82.89%for radiographs, LDCT and DCT respectively. Risk of cancer induction decreased as age increased. The difference in risk between the modalities also decreased. Males had a statistically significant higher risk than female patients (p=0.023) attributed to the sensitive organs being closer to the exposed area.
Conclusion
Effective Dose for LDCT is comparable to radiographs of the lumbar spine. Due to the known benefits image fusion brings it is recommended that LDCT replace radiographs imaging for characterisation of lumbar spine lesions identified on planar bone scan. DCT is associated with significantly higher effective dose than LDCT. Effective risk is also higher and the difference is more marked in younger female patients.

Citation

Tootell, A., McEntee, M., Szczepura, K., & Hogg, P. (2016). Effective dose and effective risk from post-SPECT imaging of the lumbar spine. Journal of Medical Imaging and Radiation Sciences, 47(3), 267-275. https://doi.org/10.1016/j.jmir.2016.04.012

• Journal Article Type: Article
• Acceptance Date: Apr 25, 2016
• Online Publication Date: Jun 28, 2016
• Publication Date: Jun 28, 2016
• Deposit Date: Apr 26, 2016
• Publicly Available Date: Jun 28, 2017
• Journal: Journal of Medical Imaging and Radiation Sciences
• Print ISSN: 1939-8654
• Electronic ISSN: 1876-7982
• Publisher: Elsevier
• Volume: 47
• Issue: 3
• Pages: 267-275
• DOI: https://doi.org/10.1016/j.jmir.2016.04.012
• Publisher URL: http://dx.doi.org/10.1016/j.jmir.2016.04.012
• Related Public URLs: http://www.journals.elsevier.com/journal-of-medical-imaging-and-radiation-sciences/