Patterns of diagnostic imaging and associated radiation exposure among long-term survivors of young adult cancer: a population-based cohort study

• Published in: BMC cancer 2015-09, Vol.15 (1), p.612, Article 612
• Main Authors: Daly, Corinne, Urbach, David R, Stukel, Thérèse A, Nathan, Paul C, Deitel, Wayne, Paszat, Lawrence F, Wilton, Andrew S, Baxter, Nancy N
• Format: Article
• Language: English
• Subjects: Adult; Breast cancer; Cancer; Cancer therapies; Clinical medicine; Clinical practice guidelines; Cohort analysis; Cohort Studies; Colorectal cancer; CT imaging; Diagnostic imaging; Diagnostic Imaging - methods; Dosimetry; Drug dosages; Female; Health aspects; Humans; Lymphoma; Male; Mammography; Medical imaging; Neoplasm Recurrence, Local - diagnosis; Neoplasms - pathology; Nuclear medicine; Nuclear weapons; Oncology; Oncology, Experimental; Radiation; Radiation Dosage; Radiation Exposure - analysis; Surveillance; Survivors; Testicular cancer; Tomography; Young Adult; Young adults
• ISSN: 1471-2407; 1471-2407
• DOI: 10.1186/s12885-015-1578-1

Survivors of young adult malignancies are at risk of accumulated exposures to radiation from repetitive diagnostic imaging. We designed a population-based cohort study to describe patterns of diagnostic imaging and cumulative diagnostic radiation exposure among survivors of young adult cancer during a survivorship time period where surveillance imaging is not typically warranted. Young adults aged 20-44 diagnosed with invasive malignancy in Ontario from 1992-1999 who lived at least 5 years from diagnosis were identified using the Ontario Cancer Registry and matched 5 to 1 to randomly selected cancer-free persons. We determined receipt of 5 modalities of diagnostic imaging and associated radiation dose received by survivors and controls from years 5-15 after diagnosis or matched referent date through administrative data. Matched pairs were censored six months prior to evidence of recurrence. 20,911 survivors and 104,524 controls had a median of 13.5 years observation. Survivors received all modalities of diagnostic imaging at significantly higher rates than controls. Survivors received CT at a 3.49-fold higher rate (95% Confidence Interval [CI]:3.37, 3.62) than controls in years 5 to 15 after diagnosis. Survivors received a mean radiation dose of 26 miliSieverts solely from diagnostic imaging in the same time period, a 4.57-fold higher dose than matched controls (95% CI: 4.39, 4.81). Long-term survivors of young adult cancer have a markedly higher rate of diagnostic imaging over time than matched controls, imaging associated with substantial radiation exposure, during a time period when surveillance is not routinely recommended.