Subpleural fibrotic interstitial lung abnormalities are implicated in non-small cell lung cancer radiotherapy outcomes
Article Category: Research Article
Online veröffentlicht: 20. Apr. 2023
Seitenbereich: 229 - 238
Eingereicht: 19. Feb. 2023
Akzeptiert: 02. Apr. 2023
DOI: https://doi.org/10.2478/raon-2023-0018
Schlüsselwörter
© 2023 Makoto Ito et al., published by Sciendo
This work is licensed under the Creative Commons Attribution 4.0 International License.
Background
The relationship between interstitial lung abnormalities (ILAs) and the outcomes of lung cancer radiotherapy is unclear. This study investigated whether specific ILA subtypes are risk factors for radiation pneumonitis (RP).
Patients and methods
This retrospective study analysed patients with non-small cell lung cancer treated with radical-intent or salvage radiotherapy. Patients were categorised into normal (no abnormalities), ILA, and interstitial lung disease (ILD) groups. The ILA group was further subclassified into non-subpleural (NS), subpleural non-fibrotic (SNF), and subpleural fibrotic (SF) types. The Kaplan–Meier and Cox regression methods were used to determine RP and survival rates and compare these outcomes between groups, respectively.
Results
Overall, 175 patients (normal, n = 105; ILA-NS, n = 5; ILA-SNF, n = 28; ILA-SF, n = 31; ILD, n = 6) were enrolled. Grade ≥2 RP was observed in 71 (41%) patients. ILAs (hazard ratio [HR]: 2.33, p = 0.008), intensity-modulated radiotherapy (HR: 0.38, p = 0.03), and lung volume receiving 20 Gy (HR: 54.8, p = 0.03) contributed to the cumulative incidence of RP. Eight patients with grade 5 RP were in the ILA group, seven of whom had ILA-SF. Among radically treated patients, the ILA group had worse 2-year overall survival (OS) than the normal group (35.3% vs 54.6%, p = 0.005). Multivariate analysis revealed that the ILA-SF group contributed to poor OS (HR: 3.07, p =0.02).
Conclusions
ILAs, particularly ILA-SF, may be important risk factors for RP, which can worsen prognosis. These findings may aid in making decisions regarding radiotherapy.