Adjuvant chemotherapy, cardiac disease history predict PCE after radiation for NSCLC
Pericardial effusion (PCE) is a common adverse side effect following thoracic radiation therapy (RT) for locally-advanced nonsmall cell lung cancer (NSCLC), a new study reveals. Additionally, PCE risk is increased by adjuvant chemotherapy.
The effects of intensity-modulated radiation therapy (IMRT) vs passive scattering proton beam therapy for locally advanced, inoperable NSCLC were assessed in 201 patients (56.2 percent male). Those with chest irradiation or PCE prior to treatment were excluded.
The primary study endpoint was development of PCE. Other outcomes included time to development – calculated from the start of RT – and overall survival (OS). Univariate and Multivariate Cox proportional hazards analyses were used to determine hazard ratios (HR) for PCE development.
Over a median follow-up of 23.9 months, participants received a median RT dose of 74 Gy and heart dose of 12.2 Gy. PCE was reported in 42.8 percent (n=86) of the patients, of which 40.3 percent (n=81) had grade 2 and 5.2 percent (n=5) had grade 3 PCE.
The 1- and 2-year cumulative PCE incidence rates were 31.4 and 45.4 percent, respectively, with a median time to development of 8.9 months.
The OS at 2 years was significantly higher in the PCE group than in those without PCE (69.0 vs 44.3 percent; p=0.012); at 5 years, the difference in corresponding OS rates decreased (43.3 vs 25.6 percent).
In multivariate analysis, heart volume receiving 35 Gy >10 percent (HR, 2.14; p=0.002), adjuvant chemotherapy (HR, 2.82; p<0.001) and history of cardiac disease (HR, 1.68; p=0.020) were all independent risk predictors for PCE.