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Gregory J. Riely, MD, PhD
Gregory J. Riely, MD, PhD
Posted: Thursday, August 8, 2024
Jeffrey D. Bradley, MD, of the University of Pennsylvania Abramson Cancer Center, Philadelphia, and colleagues aimed to determine whether dose intensity–modulated radiotherapy improves long-term patient outcomes compared with three-dimensional (3D) conformational radiotherapy among patients with unresectable, locally advanced non–small cell lung cancer (NSCLC) on combined-modality treatment. A secondary analysis of this clinical trial, published in JAMA Oncology, support the use of intensity-modulated radiotherapy in this patient population.
“Lung V5 [lung volume receiving low-dose radiation] did not affect survival, severe adverse events, or secondary cancer development in this study, casting doubt on historical lung V5 constraints,” mentioned the investigators. “Consistent with prior research, age alone should not be considered a contraindication for chemoradiotherapy.”
The secondary analysis from this phase III trial enrolled 483 patients with unresectable, locally advanced NSCLC who underwent intensity-modulated or 3D conformational radiotherapy combined with chemotherapy. Long-term outcomes such as overall survival, progression-free survival, development of second cancer, grade 3 or higher adverse events, and time to local failure were assessed. The percentage of organ volume radiation dose in Gy was represented as V(dose).
At the median follow-up of 5.2 years, 47.2% and 52.8% of patients underwent intensity-modulated and 3D conformational radiotherapy, respectively. The use of intensity-modulated radiotherapy correlated with a twofold reduction in grade 3 or higher pneumonitis vs 3D conformational radiotherapy (P = .03). Of note, univariate analysis revealed heart V20, V40, and V60 to correlate with worse overall survival (P < .001).
Compared with 3D conformational radiotherapy, intensity-modulated radiotherapy was found to significantly reduce heart V40 (P < .001). Furthermore, heart V40 (< 20%) demonstrated a better overall survival than V40 ( ≥ 20%) in general (P < .001). Multivariable analysis demonstrated that heart V40 (≥ 20%) was associated with worse overall survival (P = .01); however, lung V5 and age did not correlate with overall survival. Of note, participants who underwent either intensity-modulated or 3D conformational radiotherapy had comparable rates of secondary cancer development (6.6% vs 5.5%).
Disclosure: For full disclosures of the study authors, visit jamanetwork.com.
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