Trends in Radiation Use from 2004-2020 Among Adolescents and Young Adults with Hodgkin Lymphoma.

Background: Hodgkin Lymphoma (HL) has excellent survival rates in adolescents and young adults (AYAs, diagnosed between ages 15 - 39 years). However, survivors are at risk for treatment-related late effects. While radiation therapy (RT) de-escalation/omission has emerged as an approach to minimize late effects, no prior studies have evaluated RT use over time in AYAs with HL.

Methods: Using the National Cancer Database, we identified 40,717 AYAs diagnosed with HL between 2004 and 2020. Differences in sociodemographic and clinical variables were assessed using two-sample two-sided t-test or chi-square tests. RT use was summarized per year by frequency with 95% confidence intervals. The association of RT receipt with sociodemographic and clinical variables was modeled using logistic regression.

Results: Of the AYAs included, 20.1% received RT, with a significant decline in RT use over time from 33.9% in 2004 to 9.3% in 2020 (p<0.0001). Use of mantle RT declined over time from 40% in 2004 to 0% in 2018 (p<0.0001). Female AYAs were consistently less likely to receive RT than males. Rural versus metro setting (OR: 1.69, 95% CI 1.34 - 2.14, p<0.0001) and private versus no insurance (OR: 1.58, 95% CI: 1.42 - 1.76, p<0.0001) were associated with greater RT use.

Conclusion: Use of RT in AYAs with HL declined from 2004 - 2020, especially in female and uninsured AYAs.

Impact: While use of RT declined overall for AYAs with HL, this was not equal across groups. Research is needed to better understand disparities in RT use by rurality and insurance status.