Radiotherapy of lung cancer remains a central part of treatment, particularly for patients with locally advanced disease. With improvements in radiation techniques and the increasing use of immunotherapy, treatment approaches continue to evolve. However, important questions remain about how to improve survival, reduce toxicity, and ensure that advances seen in clinical trials are reflected in everyday practice.
Several publications in 2026 address these challenges.
A Japanese national registry study reports long-term outcomes with concurrent chemotherapy and proton therapy in unresectable stage III non-small cell lung cancer (NSCLC), including patients considered unsuitable for definitive photon-based treatment.
Meanwhile, new findings from the international PACIFIC-R study examine the risk of pneumonitis following chemoradiotherapy and consolidation durvalumab, identifying lung radiation dose and pre-existing COPD as important factors.
For small cell lung cancer, updated ESTRO–EORTC recommendations address thoracic radiotherapy planning, dose and fractionation, target delineation, and the integration of consolidation immunotherapy. The recommendations also revisit prophylactic cranial irradiation and emerging approaches such as hippocampal avoidance and adaptive radiotherapy.
Another real-world study from Scotland raises an important question about treatment access. Despite improvements associated with durvalumab, many patients with unresectable stage III NSCLC continue to receive radiotherapy alone, with poorer outcomes than those receiving combined treatment.
Together, these publications examine both the technical and clinical aspects of lung cancer radiotherapy, from proton therapy and treatment planning to immunotherapy-related toxicity and differences between clinical trial outcomes and routine care.
Here are four recent publications worth reading and what their findings mean for lung cancer radiotherapy in 2026.
Proton Therapy Shows Promising Long-Term Outcomes in Unresectable Stage III Lung Cancer
Proton therapy may offer an additional treatment option for patients with unresectable stage III non-small cell lung cancer (NSCLC), particularly when conventional photon radiotherapy cannot adequately spare surrounding healthy tissues.
A Japanese national registry study published in Radiotherapy and Oncology evaluated long-term outcomes of concurrent chemotherapy and proton therapy in 156 patients with unresectable stage III NSCLC, treated at 12 proton therapy centers between May 2016 and June 2020.
Patients received concurrent chemotherapy and proton radiotherapy at doses ranging from 60 to 74 Gy (relative biological effectiveness, RBE), delivered over 30–37 fractions. Following chemoradiotherapy, 42.3% of patients received consolidation immunotherapy with durvalumab.
The study included patients with particularly challenging treatment characteristics. Ten patients (6.4%) had interstitial pneumonia, while 31 patients (19.9%) were considered unsuitable for definitive photon-based chemoradiotherapy because of organ-at-risk dose constraints or other clinical concerns.
After a median follow-up of 49 months among surviving patients, overall survival was 72.9% at two years and 43.7% at five years. Median overall survival was 45 months.
Progression-free survival was 35.4% at two years and 21.3% at five years, with a median progression-free survival of 12 months.
Treatment-related toxicity was generally manageable. Grade 2 radiation pneumonitis occurred in 19.9% of patients, while grade 3 pneumonitis was reported in 3.2%. No grade 4 or higher toxicities or treatment-related deaths were recorded.
Importantly, patients considered unsuitable for definitive photon chemoradiotherapy were still able to undergo concurrent chemo-proton therapy. In this subgroup of 31 patients, two-year overall survival was 58.1%, and five-year overall survival was 27.5%.
The analysis also examined the integration of immunotherapy following proton chemoradiotherapy. Consolidation immune checkpoint inhibitor use was associated with improved progression-free survival in multivariable analysis, although no statistically significant overall survival benefit was demonstrated.
However, immunotherapy use was also associated with a higher risk of grade 2 or greater radiation pneumonitis, highlighting the importance of careful pulmonary toxicity monitoring.
The findings suggest that concurrent chemo-proton therapy can achieve meaningful long-term outcomes in patients with unresectable stage III NSCLC, including some for whom definitive photon treatment is difficult to deliver.
Nevertheless, the nonrandomized registry design, lack of a direct photon radiotherapy comparison group, incomplete dosimetric information, and variation in immunotherapy use limit conclusions about the superiority of proton therapy.
The study supports proton therapy as a potentially valuable option for selected patients with locally advanced NSCLC, particularly when conventional photon-based treatment cannot meet normal tissue constraints. Further prospective and randomized research is needed to determine which patients benefit most from this approach.
PACIFIC-R Identifies Risk Factors for Pneumonitis After Chemoradiotherapy and Durvalumab in Lung Cancer
Pneumonitis remains an important concern in patients with unresectable stage III non-small cell lung cancer (NSCLC) receiving consolidation durvalumab after chemoradiotherapy, particularly because both thoracic irradiation and immunotherapy can contribute to lung inflammation.
A new analysis from the international PACIFIC-R study, published in Clinical and Translational Radiation Oncology, investigated radiotherapy practices and factors associated with symptomatic pneumonitis in patients receiving durvalumab following chemoradiotherapy.
Researchers analyzed 268 patients from the larger PACIFIC-R observational cohort of 1,154 patients. The analysis included patients with complete information on the clinical and treatment characteristics evaluated as potential pneumonitis risk factors.
Most patients received concurrent chemoradiotherapy (86.6%), while 13.4% underwent sequential treatment. Intensity-modulated radiotherapy (IMRT) was the most frequently used technique, accounting for 66.8% of patients, compared with 25.7% who received three-dimensional conformal radiotherapy (3D-CRT).
During durvalumab treatment, 52 patients (19.4%) developed symptomatic pneumonitis, defined as pneumonitis of grade 2 or higher or an event requiring corticosteroid treatment, regardless of its underlying cause.
Multivariable analysis identified two significant factors associated with increased pneumonitis risk.
Higher mean lung radiation dose was associated with greater odds of symptomatic pneumonitis (OR 4.73, 95% CI 1.66–15.07), while patients with a history of chronic obstructive pulmonary disease (COPD) also had an increased risk (OR 2.60, 95% CI 1.21–5.65). The dose-related odds ratio was calculated using log-transformed mean lung dose rather than representing the effect of a 1 Gy increase.
These findings were confirmed in sensitivity analyses accounting for time to pneumonitis, with hazard ratios of 3.28 for mean lung dose and 1.93 for prior COPD.
The study also identified differences in radiotherapy practice between countries. IMRT was used more frequently than 3D-CRT overall, particularly among older patients and those with larger or more advanced tumors.
However, radiotherapy technique itself was not independently associated with symptomatic pneumonitis risk in this analysis. The findings suggest that lung radiation exposure may be more informative than the technique label alone when evaluating toxicity risk.
Pneumonitis also affected treatment continuity. Among the 52 patients who developed symptomatic pneumonitis, only 10 completed durvalumab treatment, while 31 discontinued because of an adverse event.
The authors acknowledge several limitations, including the retrospective observational design, incomplete clinical records, variable pneumonitis grading, and the relatively small analysis population compared with the full PACIFIC-R cohort. Additionally, pneumonitis events were not consistently classified as radiation-induced or immunotherapy-related.
The findings reinforce the importance of limiting mean lung radiation dose and considering pre-existing pulmonary disease when planning chemoradiotherapy followed by durvalumab.
As immunotherapy becomes increasingly integrated into locally advanced lung cancer treatment, identifying patients at greater risk of pulmonary toxicity may help clinicians optimize radiotherapy planning, monitoring, and multidisciplinary management.
ESTRO and EORTC Publish Updated Radiotherapy Recommendations for Limited-Stage Small Cell Lung Cancer
The treatment of limited-stage small cell lung cancer (SCLC) is changing with the introduction of consolidation immunotherapy, improvements in thoracic radiotherapy techniques, and growing interest in more individualized radiation schedules.
New expert recommendations from the European Society for Radiotherapy and Oncology (ESTRO) and the European Organisation for Research and Treatment of Cancer (EORTC), published in Radiotherapy and Oncology, address the use of radiotherapy in stage I–III small cell lung cancer, including target delineation, dose and fractionation, treatment planning, and integration with systemic therapies.
Developed by a multidisciplinary European expert panel, the recommendations draw on published clinical evidence and research available through January 2026.
The panel emphasizes that accurate staging is essential before curative-intent treatment. Recommended investigations include FDG PET-CT and brain MRI, with additional mediastinal staging when clinically indicated.
For fit patients with stage I–III SCLC, concurrent platinum-etoposide chemotherapy and thoracic radiotherapy remain central to treatment. Radiotherapy should preferably begin during the first or second chemotherapy cycle, although individual circumstances may justify a later start.
The recommended standard thoracic radiotherapy schedule remains 45 Gy in 30 twice-daily fractions over three weeks. An alternative is 66 Gy in 33 once-daily fractions, which may be more convenient for some patients.
Treatment planning should incorporate modern conformal techniques, including IMRT or VMAT, with involved-field rather than elective nodal irradiation. The recommendations also emphasize respiratory motion assessment using four-dimensional CT, appropriate target margins, and daily image guidance when available.
A major development is the integration of consolidation durvalumab following concurrent chemoradiotherapy in patients without disease progression. The phase III ADRIATIC trial demonstrated a significant overall survival benefit, with median survival increasing from 33.4 months with placebo to 55.9 months with durvalumab.
Based on these results, the recommendations support durvalumab initiated within 42 days after chemoradiotherapy and continued for up to two years.
The document also revisits prophylactic cranial irradiation (PCI), which remains a standard approach for responding patients. Conventional PCI is delivered at 25 Gy in 10 fractions. However, hippocampal avoidance techniques and MRI surveillance strategies are increasingly being studied to reduce potential neurocognitive toxicity.
For medically inoperable patients with peripheral T1–T2N0 disease, stereotactic body radiotherapy (SBRT) may be considered, provided accurate nodal staging and appropriate systemic treatment are included.
The authors also discuss emerging approaches such as adaptive radiotherapy, twice-daily dose escalation, and molecularly informed treatment selection. These strategies remain under investigation and are not yet established for routine use.
An important distinction is that the document represents expert recommendations rather than results from a new randomized clinical trial. Several approaches, particularly dose escalation, advanced adaptive techniques, and alternatives to PCI, still require stronger prospective evidence.
The recommendations provide an updated framework for radiotherapy in limited-stage SCLC, incorporating recent progress in immunotherapy while emphasizing accurate staging, consistent target delineation, organ-at-risk protection, and multidisciplinary treatment planning.
The main clinical message is that thoracic radiotherapy remains essential in stage I–III SCLC, with consolidation durvalumab now an important component of treatment for eligible patients. The recommendations also clarify current standards for radiotherapy delivery and identify areas where future studies could further improve survival and reduce toxicity.
Real-World Study Finds Survival Gaps in Stage III Lung Cancer Treatment Despite Durvalumab Advances
Although consolidation durvalumab has improved outcomes for patients with unresectable stage III non-small cell lung cancer (NSCLC), many patients in routine clinical practice still receive radiotherapy without chemotherapy, raising questions about access to combined treatment and opportunities to improve outcomes.
A retrospective study published in Clinical and Translational Radiation Oncology examined 656 patients with unresectable stage III NSCLC who received radical radiotherapy in the West of Scotland between January 2017 and December 2022.
The study focused on a population with substantial socioeconomic deprivation and comorbidities. The median patient age was 69 years, 62% lived in the two most deprived socioeconomic quintiles, and 81% had an ECOG performance status of 0 or 1.
Researchers compared treatment patterns and outcomes among patients receiving radiotherapy alone, sequential chemoradiotherapy, concurrent chemoradiotherapy, and concurrent chemoradiotherapy followed by durvalumab.
Despite the introduction of durvalumab, radiotherapy alone remained the most common treatment, accounting for 59% of patients. Concurrent chemoradiotherapy without durvalumab was delivered to 22%, sequential chemoradiotherapy to 9%, and concurrent chemoradiotherapy followed by durvalumab to approximately 11%.
The proportion receiving concurrent chemoradiotherapy, with or without durvalumab, increased from 27% in 2017–2018 to 39% in 2021–2022. However, the proportion treated with radiotherapy alone remained largely unchanged.
Among 372 patients included in the adjusted survival analysis, two-year progression-free survival was 64% with concurrent chemoradiotherapy plus durvalumab, compared with 39% for concurrent chemoradiotherapy alone, 41% for sequential chemoradiotherapy, and 38% for radiotherapy alone.
After adjustment for clinical characteristics, consolidation durvalumab was associated with significantly improved progression-free survival compared with concurrent chemoradiotherapy alone (HR 0.51, 95% CI 0.33–0.78; p=0.002).
However, the difference in overall survival between these two groups did not reach statistical significance within the two-year analysis.
Patients receiving radiotherapy alone had the poorest outcomes. Two-year mortality was 70% in this group, compared with 44% following concurrent chemoradiotherapy and 29% following concurrent chemoradiotherapy plus durvalumab.
Importantly, radiotherapy alone remained associated with poorer overall survival after adjustment for age, performance status, comorbidity, and socioeconomic deprivation.
The researchers also evaluated the feasibility of completing consolidation immunotherapy. Among 69 patients who started durvalumab, 55% discontinued before completing the planned 12-month course.
Adverse events were the most common reason for treatment discontinuation, with pneumonitis accounting for nine cases. Disease progression and other clinical or practical factors also contributed.
Despite early discontinuation, 53% of patients who stopped durvalumab before completing treatment remained disease-free at two years. However, this observational finding does not establish that shorter treatment is equally effective.
Another important finding was that treatment decisions appeared more strongly associated with age and performance status than with measured comorbidity or socioeconomic deprivation.
The authors suggest that current clinical assessments may not fully capture patient fitness or the barriers preventing patients from receiving combined treatment.
The study was limited by its retrospective design, differences in baseline characteristics between treatment groups, and the absence of randomized treatment allocation. Its single-center setting and restriction of survival comparisons to two years also limit interpretation.
The findings confirm the progression-free survival benefit associated with consolidation durvalumab in real-world practice, while highlighting a continuing treatment gap for patients receiving radiotherapy alone.
Improved assessment of frailty, multidisciplinary decision-making, prehabilitation, and alternative treatment strategies may help more patients with stage III NSCLC access appropriate combined-modality treatment.
