Single-isocenter SBRT vs. Multiple-isocenter SBRT for Multiple Extracranial Metastases

Exclusion criteria

• Prior radiotherapy for distant metastases if overlapping previous and current treatment plans leads to excessive dose to OARs; • Distant metastases with extension into the gastrointestinal tract, skin; • Large inter-lesion distance and location of distant metastases in different organs with different motion patterns; • Women who are pregnant or breast feeding; • Intention to become pregnant during the course of the trial; • Lack of safe contraception, defined as: Female participants of childbearing potential, not using and not willing to continue using a medically reliable method of contraception for the entire study duration, such as oral, injectable, or implantable contraceptives, or intrauterine contraceptive devices, or who are not using any other method considered sufficiently reliable by the investigator in individual cases; • Known or suspected non-compliance, drug or alcohol abuse; • Inability to follow the procedures of the trial, e.g. due to language problems of the participant; • Enrolment of the investigator, his/her family members, employees and other dependent persons. Female participants who underwent hysterectomy and/or bilateral oophorectomy or postmenopausal for longer than 2 years are not considered as being of child bearing potential.