RECENT findings have provided crucial insights into the optimal radiotherapy techniques for treating unresectable locally advanced non–small cell lung cancer (NSCLC). The study, which analysed long-term outcomes of intensity-modulated radiotherapy (IMRT) versus 3-dimensional conformal radiotherapy (3D-CRT), underscores the benefits of IMRT in reducing severe side effects and improving survival rates.
The secondary analysis of a prospective Phase III randomised clinical trial involved 483 patients who received chemoradiotherapy for locally advanced NSCLC (median [interquartile] age: 64 [57–70] years; 194 [40.2%] female). The participants were split into two groups: 228 received IMRT and 255 received 3D-CRT.
The findings indicate that IMRT offered significant advantages over 3D-CRT. Notably, IMRT was associated with a two-fold reduction in severe Grade 3 or higher pneumonitis adverse events (8 [3.5%] versus 21 [8.2%]; P=0.03). Long-term survival outcomes also favoured IMRT. Univariate analysis revealed that heart radiation doses V20, V40, and V60 were linked to worse overall survival (hazard ratios: 1.06 [95% CI: 1.04–1.09]; 1.09 [95% CI: 1.05–1.13]; 1.16 [95% CI, 1.09–1.24], respectively; all P<0.001). IMRT significantly reduced the heart V40 radiation dose compared to 3D-CRT, which translated into better survival rates (16.5% versus 20.5%; P<0.001) Patients with a heart V40 <20% had a median overall survival of 2.5 years, compared to 1.7 years for those with a heart V40 of ≥20%.
The study also found that lung V5 radiation doses and patient age were not associated with overall survival, suggesting that these factors should not be considered contraindications for chemoradiotherapy.
The research concluded that IMRT should be preferred over 3D-CRT for patients with locally advanced NSCLC, particularly focusing on reducing radiation doses to critical organs. This approach could potentially set new standards in radiotherapy, offering hope for better long-term survival and quality of life for patients battling this challenging form of cancer.
Ada Enesco, EMJ
Reference
Radiation Therapy Oncology Group. High-dose or standard-dose radiation therapy and chemotherapy with or without cetuximab in treating patients with newly diagnosed Stage III non-small cell lung cancer that cannot be removed by surgery. NCT00533949. https://clinicaltrials.gov/study/NCT00533949
