Acute hospitalizations after proton therapy versus intensity-modulated radiotherapy for locally advanced non-small cell lung cancer in the durvalumab era

Cancer. 2024 Jun 1;130(11):2031-2041. doi: 10.1002/cncr.35230. Epub 2024 Jan 31.

Abstract

Introduction: It was hypothesized that use of proton beam therapy (PBT) in patients with locally advanced non-small cell lung cancer treated with concurrent chemoradiation and consolidative immune checkpoint inhibition is associated with fewer unplanned hospitalizations compared with intensity-modulated radiotherapy (IMRT).

Methods: Patients with locally advanced non-small cell lung cancer treated between October 2017 and December 2021 with concurrent chemoradiation with either IMRT or PBT ± consolidative immune checkpoint inhibition were retrospectively identified. Logistic regression was used to assess the association of radiation therapy technique with 90-day hospitalization and grade 3 (G3+) lymphopenia. Competing risk regression was used to compare G3+ pneumonitis, G3+ esophagitis, and G3+ cardiac events. Kaplan-Meier method was used for progression-free survival and overall survival. Inverse probability treatment weighting was applied to adjust for differences in PBT and IMRT groups.

Results: Of 316 patients, 117 (37%) received PBT and 199 (63%) received IMRT. The PBT group was older (p < .001) and had higher Charlson Comorbidity Index scores (p = .02). The PBT group received a lower mean heart dose (p < .0001), left anterior descending artery V15 Gy (p = .001), mean lung dose (p = .008), and effective dose to immune circulating cells (p < .001). On inverse probability treatment weighting analysis, PBT was associated with fewer unplanned hospitalizations (adjusted odds ratio, 0.55; 95% CI, 0.38-0.81; p = .002) and less G3+ lymphopenia (adjusted odds ratio, 0.55; 95% CI, 0.37-0.81; p = .003). There was no difference in other G3+ toxicities, progression-free survival, or overall survival.

Conclusions: PBT is associated with fewer unplanned hospitalizations, lower effective dose to immune circulating cells and less G3+ lymphopenia compared with IMRT. Minimizing dose to lymphocytes may be warranted, but prospective data are needed.

Keywords: carcinoma; hospitalization; intensity‐modulated; lung neoplasms; lymphopenia; non‐small cell lung; proton therapy; radiotherapy.

Publication types

  • Comparative Study

MeSH terms

  • Aged
  • Antibodies, Monoclonal
  • Carcinoma, Non-Small-Cell Lung* / drug therapy
  • Carcinoma, Non-Small-Cell Lung* / pathology
  • Carcinoma, Non-Small-Cell Lung* / radiotherapy
  • Carcinoma, Non-Small-Cell Lung* / therapy
  • Chemoradiotherapy* / adverse effects
  • Chemoradiotherapy* / methods
  • Female
  • Hospitalization* / statistics & numerical data
  • Humans
  • Immune Checkpoint Inhibitors / adverse effects
  • Immune Checkpoint Inhibitors / therapeutic use
  • Lung Neoplasms* / drug therapy
  • Lung Neoplasms* / mortality
  • Lung Neoplasms* / pathology
  • Lung Neoplasms* / radiotherapy
  • Lung Neoplasms* / therapy
  • Lymphopenia / etiology
  • Male
  • Middle Aged
  • Proton Therapy* / adverse effects
  • Proton Therapy* / methods
  • Radiotherapy, Intensity-Modulated* / adverse effects
  • Radiotherapy, Intensity-Modulated* / methods
  • Retrospective Studies

Substances

  • durvalumab