Association of Thoraco-mediastinal Radiotherapy With Maintenance Immunotherapy Treatment With Atezolizumab

Prospective phase II study on patients affected by extensive-stage small cell lung cancer. The traditional treatment of lung microcytoma-extensive disease consists in platinum and etoposide-based chemotherapy. Radiotherapy of consolidation at the thoracic mediastinal level after chemotherapy may have an impact on survival and can be offered to patients in response to chemotherapy. Studies have recently shown that the addition of immunotherapy with atezolizumab to traditional chemotherapy improves survival compared to placebo. However, the use of consolidation radiotherapy was not permitted in the study thoracic level. Therefore the objective is to evaluate the efficacy and tolerance of the thoracic radiotherapy-immunotherapy association in the maintenance phase with atezolizumab of the treatment of lung microcytoma - extensive disease treated with chemo-immunotherapy.

Inclusion criteria

• Histological diagnosis of lung microcytoma;
• Age ≥18 years;
• Performance status according to ECOG 0-2;
• Extended disease at the time of first line oncological treatment;
• Initial staging and restaging after chemo-immunotherapy with CT, CT-PET FDG and brain MRI;
• In at least partial response (defined according to the Recist criteria [18]) after treatment chemoimmunotherapy according to the Impower 133 scheme;
• Haematological, respiratory toxicity ≤ G1, other toxicities ≤ G2 at the time of treatment radiotherapy;
• Pulmonary function tests at the time of radiotherapy treatment compatible with irradiation: FEV≥1.2 l or >40%, DLCO≥50%;
• Written informed consent.

Exclusion criteria

• Previous radiotherapy treatment at the thoraco-mediastinal level;
• In disease progression after chemo-immunotherapy treatment.