Table 10.

Key recommendations regarding the use of radiation therapy.

Radiation therapy approach	Key recommendations
Radiation therapy for thoracic disease	•Indicated in LS-SCLC patients (stage III disease) in combination with chemotherapy. •Is preferred to start the radiation therapy during the first/second cycle of chemotherapy according to the extent of the target volume.
Thoracic consolidation	•Indicated in ES-SCLC patients (stage IV disease) in response to chemotherapy or chemo-immunotherapy with mediastinal residue. •The total dose has to be defined in accordance to the extent of thoracic disease and to the dose constraints to organs at risk. •Is preferred to start within 6–8 weeks after completion of chemotherapy. •In case of consolidation with immunotherapy, patient selection should occur prior to the immunological consolidation phase (studies on radio-immunotherapy concomitance demonstrated the feasibility of the combination).
PCI	•Indicated in patients responding to first-line systemic therapy. •The decision to perform PCI should be based on brain magnetic resonance imaging (MRI) restaging. •PCI is not recommended for stage I patients due to risk/benefit ratio. •PCI should be considered for LS-SCLC patients in stage II-III <70 years with good performance status (ECOG 0–2) and responding to thoracic chemoradiation. •A shared decision-making process on the role of PCI is recommended in LS-SCLC patients with limited PS, advanced age, and/or significant comorbidities •In ES-SCLC patients in response to first-line therapy, a dedicated discussion with the radiation oncologist is recommended to improve the shared decision-making process between PCI and surveillance with MRI, considering patient and disease-specific characteristics. •Techniques allowing hippocampus sparing can be considered to reduce cognitive deficits, given the low incidence of metastatic localization in that area.
Treatment of encephalic metastases	•Indicated when brain MRI shows positive disease localization. •Consider hippocampal sparing if no lesions are present in that area. •Evaluate stereotactic approach for positive MRI sites after a shared discussion, considering potential neurocognitive damage, PS and patient prognosis.
Treatment of bone metastases	•Indicated for pain relief, risk of fracture, or spinal cord involvement. •Evaluate total dose and fractions based on life expectancy, PS, lesion site and size.
Palliative treatment of thoracic disease	•Indicated for mediastinal syndrome or haemostatic purposes. •Evaluate total dose and fractions based on life expectancy, PS, lesion site and size.
Stereotactic radiation therapy	•Indicated for stage I patients (T1/T2-N0) when other approaches are excluded due to comorbidities. •Indicated for patients with lung lesions; total dose and fractions depend on the site and size of the lesion (lesions <2 cm from mediastinum/bronchi, lesions adjacent to the thoracic wall or lesions in the central parenchyma), typically delivered in 1–8 sessions. •Indicated for oligometastatic patients with distant disease sites, in cases of radical treatment for primary tumor. •Indicated for oligoprogression during systemic therapy.