Radiation exposure and attributed cancer risk following lung transplantation

Abstract

Background: Lung transplant recipients are exposed to radiation from various imaging procedures during surveillance; however, the cumulative radiation exposure and subsequent cancer risk after lung transplantation is not known.

Methods: We included all patients who underwent lung transplantation at our institute since January 2000 and survived at least four-yr follow-up continued until March 21, 2012 or until death. We identified all procedures with radiation exposure and all malignancies that developed during the study period. Estimation of the effective dose exposure and subsequent cancer risk was derived from previous reports.

Results: The study included 107 patients. Mean follow-up was 6.49 ± 1.74 yr. Radiation exposure during mean follow-up was 137.8 mSv, and the total cumulative exposure over 11 yr reached 205.25 mSv. This represents an additional cancer risk of 0.55% and 0.82%, respectively. Twenty-four cases of cancer in 21 patients (19.6%) were identified. The difference between the radiation exposure in the patients who developed cancer and in the cancer-free patients was not statistically significant.

Conclusion: Lung transplant recipients are exposed to 7.8 times greater radiation dose from medical imaging compared to the general population. Nevertheless, the lifetime increase in cancer risk due to radiation is small.

Keywords: cancer; imaging; lung; radiation; transplantation.