Background: Concerns regarding the risks of cancer and cancer-related death as a result of radiation from computed tomography (CT) scans and the lack of data demonstrating a survival advantage for surveillance CT scans following lymphoma therapy have raised questions regarding their benefit. We compared the radiation-related lifetime cancer incidence (LCI) and mortality risks (LCMRs) associated with CT scans for staging and surveillance of non-Hodgkin lymphoma (NHL) and Hodgkin lymphoma (HL) with the cumulative probability of lymphoma death (CPLD) during surveillance.
Patients and methods: The LCI and LCMR were calculated using published estimates of the cumulative organ-specific radiation doses from full-body CT scans and sex-, age-, and organ-dependent cancer risks per 0.1 Gy provided by the Biologic Effects of Ionizing Radiations VII report. Surveillance, Epidemiology, and End Results (SEER) data were used to identify cases between 2000 and 2006 from 17 SEER registries and calculate CPLD for specified cohorts.
Results: For a 70-year-old patient, a single full-body CT examination is associated with a LCI of 0.044% and 0.057%, and a LCMR of 0.032% and 0.044% for males and females, respectively. For 20-year-old patients the LCMRs were 0.071% for men and 0.108% for women. The LCI and LCMR were lower for males and were markedly less than the CPLD at 5 years for most lymphoma subtypes, but relevant for younger women with HL.
Conclusion: Although the LCMR from CT scans is small compared with lymphoma-related deaths for most subgroups, these data should be discussed with patients in formulating plans for surveillance following lymphoma therapy.