Abstract
Purpose
To evaluate the impact of the reduced life expectancy of patients (compared to a nonpatient group with the same age distribution) on their nominal risk of developing cancer from the diagnostic use of radiation.
Method
We define a “prognosis-based lifetime attributable risk modifier” (PROLARM) as the ratio of the risks for nonpatients and patients, a dimensionless quantity which indicates how strongly the life-time attributable risk (LAR) is reduced due to a patient’s prognosis. An approximation to this ratio can be given (named PROLARA) which depends only on the patient’s age at exposure and his/her life expectancy, but is independent of the exact choice of values for the baseline risk of cancer incidence and the excess relative risk (ERR) from radiation exposure. PROLARM and PROLARA were computed for a cohort of 4,285 female patients with metastatic breast cancer, for whom all necessary input data were available.
Results
LAR of solid cancer was significantly decreased in these patients: PROLARM >20 for age at exposure ≤65 years. For any reasonable choice of function for ERR, the approximation PROLARA gave a lower estimate of the reduction in risk. The risk for a patient from the above cohort, exposed at age 50 years, is decreased by a factor of 29 (PROLARM) and 27 (PROLARA). In other words, 50 mSv in a patient with metastatic breast cancer corresponds risk-wise to only 2 mSv in a nonpatient of the same age.
Conclusion
A major proportion of the total dose from diagnostic medical exposures does not constitute an additional cancer risk due to the poorer prognosis of patients compared to nonpatients of same gender and age. Our new PROLARA concept allows an estimation of the reduction in risk for any pathology when the associated survival is known.
References
Berrington de Gonzalez A, Darby S. Risk of cancer from diagnostic X-rays: estimates for the UK and 14 other countries. Lancet 2004;363:345–51.
Brenner DJ, Hall EJ. Computed tomography – an increasing source of radiation exposure. N Engl J Med 2007;357:2277–84.
Vaeth M, Pierce DA. Calculating excess lifetime risk in relative risk models. Environ Health Perspect 1990;87:83–94.
Kellerer AM, Nekolla EA, Walsh L. On the conversion of solid cancer excess relative risk into lifetime attributable risk. Radiat Environ Biophys 2001;40:249–57.
National Research Council. Committee to assess health risks from exposure to low levels of ionizing radiation. Health risks from exposure to low levels of ionizing radiation. BEIR VII Phase 2. Washington DC: National Academy Press; 2006.
ICRP. The 2007 recommendations of the International Commission on Radiological Protection, ICRP publication 103. Ann ICRP 2007;37:1–332.
Federal Statistical Office. Lifetable of Germany. http://www.destatis.de/jetspeed/portal/cms/Sites/destatis/Internet/EN/Content/Statistics/Bevoelkerung/GeburtenSterbefaelle/Tabellen/Content100/SterbetafelDeutschland
ICRP. 1990 recommendations of the International Commission on Radiological Protection, ICRP Publication 60. Ann ICRP 1991;21:1–201.
Cancer in Germany, 2003–2004. Incidence and trends. Sixth edition. Robert Koch Institute (ed.) and Association of Population-based Cancer Registries in Germany (ed.). Berlin; 2008.
Smolarz K, Eschner W, Schicha H. Influence of disease prognosis and age on the radiation risk from diagnostic nuclear medicine (bone scintigraphy as an example). Nuklearmedizin 1998;37:286–91.
Acknowledgments
The authors wish to thank M. Schmidt of the Munich Cancer Registry/IBE for providing the patient survival data (www.tumorregister-muenchen.de).
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Eschner, W., Schmidt, M., Dietlein, M. et al. PROLARA: prognosis-based lifetime attributable risk approximation for cancer from diagnostic radiation exposure. Eur J Nucl Med Mol Imaging 37, 131–135 (2010). https://doi.org/10.1007/s00259-009-1221-y
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00259-009-1221-y