Single-Fraction Pulmonary Ablative Radiotherapy Outcomes and Quality-of-life Workup

Pulmonary tumors, whether primary or metastatic, represent a major challenge in oncology. Lung cancer remains the leading cause of cancer-related mortality in France, with nearly 37,000 annual deaths. Pulmonary metastases, present in approximately 20% of patients with solid tumors, highlight the complexity of managing secondary tumors, particularly in the context of oligometastatic cancers. These cancers, characterized by a limited number of metastases (generally ≤3 to 5), have garnered increasing attention due to their potentially improved prognosis with the use of local ablative therapies. Stereotactic body radiotherapy (SBRT) is a technique that delivers high doses of radiation with great precision over a limited number of sessions (1 to 5 fractions compared to around 30 in conventional radiotherapy). For primary lesions, SBRT has demonstrated local control rates exceeding 90% and a 5-year survival rate of 87% (Chang et al., 2015). Similarly, promising outcomes have been reported for oligometastatic pulmonary lesions, with improvements in progression-free and overall survival compared to standard of care. Consequently, SBRT has become a key therapeutic option for pulmonary tumors, whether primary or secondary. During the recent COVID-19 pandemic, monofraction protocols (30 or 34 Gy) were implemented. Their equivalence has been demonstrated for both primary lesions and secondary lesions, and they have been included in clinical guidelines. Single-session treatments are particularly advantageous for patients with poor general health or those living far from treatment centers, as they help to minimize travel requirements. However, although SBRT in a single fraction offers promising prospects, data on its impact on quality of life remain limited, especially for patients with non-small cell lung cancer. Such information is crucial to guide the integration of this strategy into clinical practice and to assess its benefits in the context of personalized care. This bicentric ambispective observational study (RIPH 3 according to the Jardé Law) aims to evaluate the quality of life of patients treated with single-fraction pulmonary SBRT using the EORTC QLQ C30 and LC-29 questionnaires. The primary endpoint will be analyzed prospectively in newly treated patients, while retrospective data will be included for secondary endpoints: tolerance (specifically grade ≥ 3 toxicities), efficacy (local control, progression-free survival, overall survival), and dosimetric parameters. The study involves patients with primitive (NSCLC T1-2N0) or oligometastatic (≤ 3 tumors) lung tumor who are inoperable or refuse surgery, treated with stereotactic radiotherapy delivering 34 Gy in a single session at two cancer centers (Institut de Cancérologie de Montpellier and Institut de Cancérologie de Lorraine). Patients will be asked to complete standardized quality-of-life questionnaires in French, the EORTC QLQ C30 and LC-29, pre-treatment, at M1, M3, M6, M9 and M12. These questionnaire completion times correspond to standard radiological assessments as part of the patient's medical management and follow-up.