Independent Review Organization and Proton Therapy: Multistate Analysis and Legal Procedural Strategies

Purpose: Securing insurance authorization for proton therapy remains a challenge for many centers. When health insurance or employer-sponsored health plans deny coverage, Independent Review Organizations (IROs) can review proton therapy cases. However, despite providing an independent review pathway, IROs are often underutilized in securing approvals for care following a denial. Materials and Methods: We analyzed trends in IRO approvals, strategies, and legal procedures using publicly available data from California (CA), Washington (WA), and New York (NY). Results: The aggregate analysis of the 3 states revealed an IRO average approval rate for proton therapy of 42.1%, with varying trends across states. All 3 states showed increases in IRO approval rates over time, averaging annual increases of +5.0%, +2.3%, and +7.2% for CA, WA, and NY, respectively. Sarcoma showed the highest IRO approval rate at 84.6%, followed by GYN cancers at 55.6% and breast cancer at 51.4%. CNS tumors and lymphomas had moderate approval rates at 44.7% and 40.0% respectively. Head and neck cancers had a 33.3% approval rate, while thoracic malignancies were at 36.8%. The lowest IRO approval rate was seen in prostate cancer at 16.5%. Qualitative analysis revealed that referencing guidelines, discussing published studies, citing trial inclusion, and submitting personalized letters were associated with higher IRO approval rates. Conclusion: IRO reviews provide a more objective remedy for patients denied care through internal appeals, particularly for plans with historically unfavorable proton policies. Our study demonstrates that IRO appeals provide a valuable pathway to proton therapy access with higher overturn rates improving significantly in recent years. Nearly half of initially denied patients eventually received approval through this process. Proton centers should strategically utilize IRO reviews to increase patient access and improve approval chances.