Utilization of Intensity-Modulated Radiation Therapy for Malignant Pleural Mesothelioma in the United States

Abstract Background Although postoperative radiotherapy (RT) for malignant pleural mesothelioma (MPM) has historically been delivered using 3-dimensional conformal RT (3DCRT) techniques, multiple reports show noteworthy safety and efficacy of the more advanced intensity-modulated RT (IMRT). To our knowledge, this is the only known study to evaluate national practice patterns of IMRT utilization for MPM. Materials and Methods The National Cancer Data Base was queried for newly-diagnosed MPM patients who underwent definitive surgery (extrapleural pneumonectomy [EPP] or extended pleurectomy/decortication [P/D]) followed by adjuvant RT. Patients with metastatic disease, non-EPP or P/D surgical techniques, and lack of RT receipt (or without specified RT technique) were excluded. Statistics included multivariable logistic regression, Kaplan–Meier overall survival (OS) analysis, and Cox proportional hazards modeling. Results Overall, 286 patients met criteria (181 [63%] IMRT and 105 [37%] 3DCRT). Temporal trends revealed that although 3DCRT was more common at initial time periods, IMRT utilization rose from 2004 to 2007 and stayed as a relatively constant majority thereafter. This was also present when substratifying the cohort according to EPP versus P/D approaches. IMRT was more often delivered at academic centers, along with institutions in the Southern United States, whereas 3DCRT was more frequently utilized in community facilities and in the Northeast ( P  ≤ .05 for all). RT technique did not affect OS ( P  > .05 for all comparisons). Conclusion In the United States, IMRT is now the most commonly utilized adjuvant RT technique for MPM. Facility and regional differences might associate with IMRT delivery. The findings of this investigation have implications for insurance coverage, clinical referral patterns, and ongoing and future prospective trial design.