Findings in context
How do the results of the current study sit with other studies of SBRT in non–small cell lung cancer? Dr. Lievens pointed out that overall survival at 2 years was lower in the current trial (52%) than in patients with central tumors treated in the RTOG 0813 trial (68%-73%) or those with peripheral tumors in the CHISEL trial (77%).
There were, of course, different fractions and doses of radiotherapy used in these trials, with lower doses and more fractions in the UMC Utrecht study, and there was higher toxicity when ultra-central lesions were treated.
“Optimized radiotherapy dose fractionation regimens are investigated quite intensively to improve the clinical benefit. This is an important area of research,” Dr. Lievens said.
The high local control rates but serious risk of bronchopulmonary hemorrhage seen in the current study “calls for further investigation of dose/volume parameters in the context of the location of the tumor but also in the context of other treatment modalities,” she added. “Advanced technologies in radiotherapy, which allow better imaging and daily adaptation, such as the MR-Linac, can optimize clinical benefits.”
The study was supported by UMC Utrecht and received no commercial funding. Dr. Lodeweges and Dr. Lievens had no relevant conflicts of interest.