This study aims at enrolling patients with solid tumors at metastatic stage, considered long responders to immunotherapy (\> 6 months) and displaying disease progression.
In this study, the investigator wants to evaluate specific modalities of stereotactic radiotherapy, with 3 sessions, each of 8 Gy, lasting 20 minutes and spaced 72 hours apart (Day 1, Day 4, Day 7). The radiotherapy device itself is not the subject of this study and will be used in accordance with its CE mark and indications.
The objective of the study is to assess the ability of stereotactic radiotherapy to restore the lost efficacy of immunotherapy. In particular, the abscopal effect will be assessed, i.e. the action of irradiating a particular target lesion and observing an effect on other distant metastases.
Male or female, 18 years of age or older,
Patient with a metastatic solid tumor,
Patient with at least one target lesion (for radiotherapy) together with other secondary lesions that must be measurable,
Measurable disease according to RECIST 1.1 and iRECIST criteria,
Patient having received previous radiotherapy since the start of immunotherapy,
Patient for whom first disease progression (pre-inclusion stage) is not confirmed secondarily (inclusion stage),
Patient with an active implantable medical device (e.g. pacemaker) or an active medical device worn on the body that could interact adversely with stereotactic radiotherapy treatment,
Patient with hematological cancer,