Stereotactic body radiotherapy for early-stage non-small cell lung cancer: a multicentre study by the Oncologic Group for the Study of Lung Cancer (Spanish Radiation Oncology Society)

PURPOSE/OBJECTIVE(S)

Stereotactic body radiotherapy (SBRT) has become the standard of care for patients with medically inoperable early-stage non-small cell lung cancer (NSCLC) and for patients who refuse surgery. The aim of this study was to evaluate the effectiveness and safety of primary SBRT in patients with early-stage NSCLC.

MATERIALS/METHODS

Retrospective multicenter study of 397 patients (416 primary lung tumours) treated with SBRT at 18 centres in Spain. 83.2% were men. The median age was 74.4 years. In 94.4% of cases, the tumour was inoperable. The pathological report was available in 54.6% of cases. SPSS vs 22.0. was used to perform all statistical analyses.

RESULTS

Complete response was obtained in 53.6% of cases. Significant prognostic factors were standard CT planning (p = 0.014) and 4D cone beam CT (p = 0.000). Acute and chronic toxicity ≥ grade 3 was observed in 1.2% of cases. At a median follow-up of 30 months, local relapse was 9.6%, lymph node relapse 12.8%, distant metastasis 16.6%, and another lung tumour 11.5%. Complete response was the only significant prognostic factor for local relapse (p = 0.012) and distant metastasis (p = 0.001). The local relapse-free survival was 88.7%. The overall survival was 75.7%. The cancer-specific survival was 92.7%. The disease-free survival was 78.7%.

CONCLUSION

SBRT is an effective and well-tolerated treatment option for patients with early-stage lung cancer who are not suitable for surgery. The most important prognostic factor for local and distant recurrence was complete response, which in our sample depended on the type of CT planning and the IGRT technique.

How to integrate stereotactic body radiation therapy and hypofractionation in the management of stage III lung cancer in the age of immunotherapy

The constant advances in the field of lung cancer immunotherapy have recently reached the treatment of locally advanced disease with the approval of durvalumab after concurrent chemoradiation. However, radiation therapy continues to be key for controlling the disease at this stage. Over the years, different strategies have been employed to try to optimize outcomes using radiotherapy, with cardiac and pulmonary toxicity as the main limitation on its success. The interest in the use of hypofractionation and stereotactic body radiation therapy for stage III non-small cell lung cancer has increased as knowledge regarding these kinds of treatments has been enhanced. Hypofractionation is a relatively frequent treatment, although the level of evidence that supports it is limited. For its part, stereotactic body radiation therapy has been particularly studied as a boost after chemoradiation, with encouraging results. In both cases, study of how to integrate these tools with chemotherapy and particularly with immunotherapy is essential, as they may have an immunomodulatory role.