Socioeconomic factors affect the selection of proton radiation therapy for children

BACKGROUND Proton radiotherapy remains a limited resource despite its clear potential for reducing radiation doses to normal tissues and late effects in children in comparison with photon therapy. This study examined the impact of race and socioeconomic factors on the use of proton therapy in children with solid malignancies. METHODS This study evaluated 12,101 children (age ≤ 21 years) in the National Cancer Data Base who had been diagnosed with a solid malignancy between 2004 and 2013 and had received photon- or proton-based radiotherapy. Logistic regression analysis was used to evaluate patient, tumor, and socioeconomic variables affecting treatment with proton radiotherapy versus photon radiotherapy. RESULTS Eight percent of the patients in the entire cohort received proton radiotherapy, and this proportion increased between 2004 (1.7%) and 2013 (17.5%). Proton therapy was more frequently used in younger patients (age ≤ 10 years; odds ratio [OR], 1.9; 95% confidence interval [CI], 1.6-2.2) and in patients with bone/joint primaries and ependymoma, medulloblastoma, and rhabdomyosarcoma histologies (P < .05). Patients with metastatic disease were less likely to receive proton therapy (OR, 0.4; 95% CI, 0.3-0.6). Patients with private/managed care were more likely than patients with Medicaid or no insurance to receive proton therapy (P < .0001). A higher median household income and educational attainment were also associated with increased proton use (P < .001). Patients treated with proton therapy versus photon therapy were more likely to travel more than 200 miles (13% vs 5%; P < .0001). CONCLUSIONS Socioeconomic factors affect the use of proton radiotherapy in children. Whether this disparity is related to differences in the referral patterns, the knowledge of treatment modalities, or the ability to travel for therapy needs to be further clarified. Improving access to proton therapy in underserved pediatric populations is essential. Cancer 2017;123:4048-56. © 2017 American Cancer Society.