Curatively Intended Thoracic Reirradiation

Inclusion Criteria: * Radiotherapy of thoracic lesion(s) (loco-regional lung cancer recurrence, new primary lung cancer, or solitary oligo metastasis) with the aim of long-term local control. * Reirradiation type 1 or type 2, i.e. previous radiotherapy to the thorax as per ESTRO-EORTC consensus definition of reirradiation \[Andratschke 2022\]. For the sake of this study, multiple treatments to the lungs will be classified as type 2 reirradiation. * Verification of malignancy based on biopsy. If no biopsy is available, the decision of reirradiation should be agreed upon in a multidisciplinary conference. * Available digital dose plan(s) from former radiotherapy course(s) (DICOM files) - note that multiple re-treatments are allowed. * Adequate lung function to tolerate treatment, at the discretion of the treating physician. * Ability to complete a radiotherapy course with the aim of local control. * ECOG Performance status 0-2. * Estimated life expectancy ≥ 6 months * Age ≥18 years * Signed informed consent Exclusion Criteria: * Uncontrolled other malignancy. * The primary and the reirradiation treatment may not be quasi-simultaneous (i.e. the two treatments should be planned independently) * Pregnancy * Radiotherapy to a minimum CTV mean dose of 45 Gy for SCLC and 50 Gy for NSCLC and oligometastatic lesions. Treatment schedule according to local protocols and treating physician preference.