A recent study by Karl Landsteiner University of Health Sciences (KL Krems) has revealed that higher-than-standard radiation doses can be safely combined with immunotherapy in treating inoperable lung cancer. Patients who received 70 Gy of radiation—exceeding the conventional 60 Gy threshold—prior to treatment with the immune checkpoint inhibitor Durvalumab did not face a higher risk of severe lung inflammation (pneumonitis). In fact, the data suggest a promising survival benefit with the intensified treatment approach.
Background: Standard Care and Its Limitations
Lung cancer continues to be one of the leading causes of cancer-related deaths worldwide. For patients with inoperable stage III non-small cell lung cancer (NSCLC), the current standard of care includes concurrent chemoradiotherapy (CCRT) followed by Durvalumab immunotherapy. This regimen is especially effective in tumors expressing the PD-L1 protein, which helps cancer cells evade immune detection. However, since both radiation and immunotherapy can cause pneumonitis, radiation doses have traditionally been capped at 60 Gy to minimize the risk of lung toxicity.
Rethinking the Dose: Encouraging Results from a Retrospective Study
To explore whether higher doses could enhance tumor control without increasing side effects, researchers at KL Krems conducted a retrospective analysis involving 39 patients. Of these, 29 received a radiation dose of 70 Gy, while 10 were treated with a lower, individualized dose. Both groups had similar baseline characteristics, ensuring a valid comparison.
According to Dr. Felix Schragel, a pulmonologist at University Hospital Krems, “Increasing the radiation dose to 70 Gy did not result in a higher incidence of pneumonitis. In fact, we observed a trend toward improved overall survival.”
Pneumonitis Rates Remained Comparable
Interestingly, the incidence of pneumonitis was actually lower in the high-dose group. Although 38.5% of all participants developed pneumonitis, only 34.5% of patients in the 70 Gy group experienced it, compared to 50% in the lower-dose group. Moreover, the only case of severe pneumonitis (grade 3) occurred in the lower-dose group. Most cases across both groups were mild to moderate in severity.
Survival Outcomes Favor Higher Dose
As per the press release, the survival data further underscore the benefits of the higher dose. Over 93% of patients in the 70 Gy group were alive one year after treatment, and this survival rate held steady even after four years. In contrast, patients in the lower-dose group had a median survival of 31 months and experienced more frequent tumor progression.
Precision Planning Prevents Lung Damage
The study’s success hinged on meticulous treatment planning. Clinicians maintained the mean lung dose (MLD) below the critical threshold of 20 Gy in both groups. Dr. Schragel emphasizes, “As long as clinicians adhere to safety limits—particularly in terms of low-dose lung volumes—we don’t expect an increased risk of pneumonitis.”
Toward More Personalized Treatment Strategies
Researchers support a more personalized approach to treating unresectable NSCLC based on these findings. For patients with stable lung function, clinicians may significantly enhance survival outcomes by using intensified radiotherapy. Dr. Schragel notes, “This research shows that properly planned treatment can allow higher radiation doses without necessarily causing more side effects.”
Challenging Conventional Protocols with Evidence-Based Insights
KL Krems continues to play a leading role in transforming clinical practice through evidence-driven research. This study not only demonstrates the feasibility of using higher radiation doses safely but also encourages ongoing re-evaluation of established treatment thresholds, especially as new modalities like immunotherapy reshape the therapeutic landscape.