Association of ionizing radiation dose from common medical diagnostic procedures and lymphoma risk in the Epilymph case-control study

PLoS One. 2020 Jul 10;15(7):e0235658. doi: 10.1371/journal.pone.0235658. eCollection 2020.


Medical diagnostic X-rays are an important source of ionizing radiation (IR) exposure in the general population; however, it is unclear if the resulting low patient doses increase lymphoma risk. We examined the association between lifetime medical diagnostic X-ray dose and lymphoma risk, taking into account potential confounding factors, including medical history. The international Epilymph study (conducted in the Czech-Republic, France, Germany, Ireland, Italy, and Spain) collected self-reported information on common diagnostic X-ray procedures from 2,362 lymphoma cases and 2,465 frequency-matched (age, sex, country) controls. Individual lifetime cumulative bone marrow (BM) dose was estimated using time period-based dose estimates for different procedures and body parts. The association between categories of BM dose and lymphoma risk was examined using unconditional logistic regression models adjusting for matching factors, socioeconomic variables, and the presence of underlying medical conditions (atopic, autoimmune, infectious diseases, osteoarthritis, having had a sick childhood, and family history of lymphoma) as potential confounders of the association. Cumulative BM dose was low (median 2.25 mGy) and was not positively associated with lymphoma risk. Odds ratios (ORs) were consistently less than 1.0 in all dose categories compared to the reference category (less than 1 mGy). Results were similar after adjustment for potential confounding factors, when using different exposure scenarios, and in analyses by lymphoma subtype and by type of control (hospital-, population-based). Overall no increased risk of lymphoma was observed. The reduced ORs may be related to unmeasured confounding or other sources of systematic bias.We found little evidence that chronic medical conditions confound lymphoma risk and medical radiation associations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Aged
  • Bone Marrow / pathology
  • Bone Marrow / radiation effects
  • Case-Control Studies
  • Female
  • Humans
  • Logistic Models
  • Lymphoma / diagnosis
  • Lymphoma / etiology*
  • Male
  • Middle Aged
  • Odds Ratio
  • Radiation Dosage
  • Radiation Exposure / adverse effects*
  • Radiation, Ionizing*
  • Risk Factors

Grant support

This work was supported by: The EC 5th Framework Program Quality of Life (grant No. QLK4-CT-2000-00422); La Fondation de France (No. 1999 0084 71); the German federal Office of Radiation Protection (grants No. StSch4261 and stSch4420); the Irish Health Research Board; the Spanish Ministry of Health (grant No. FIS 04-0091); and CIBERESP (Spain). The EC 5th Framework Program Quality of Life (grant No. QLK4-CT-2000-00422); the Agència de Gestió d’Ajuts Universitaris i de Recerca (AGAUR)-Generalitat de Catalunya (Catalonian Government) (grants AGAUR 2017SGR1085); Consejo de Seguridad Nuclear (Spanish nuclear safety authority to EP); Departament de Salut, Generalitat de Catalunya (SLT002/16/00232 to MCT); Instituto de Salud Carlos III (The Spanish Ministry of Health, grant No. PI14/01219 to YB and PI17/01288 to DC); Ministerio de Ciencia, Innovación y Universidades (RYC 2017 01892 to MCT). MCT acknowledges the Ramón y Cajal fellowship (RYC-2017-01892) from the Spanish Ministry of Science, Innovation and Universities and cofunded by the European Social Fund. ISGlobal acknowledges support from the Spanish Ministry of Science, Innovation and Universities through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S), and support from the Generalitat de Catalunya through the CERCA Program.