Design: Prospective, single-center, exploratory clinical study. Patient Enrollment: The study intends to enroll patients diagnosed with malignant tumors requiring fiducial marker-guided SBRT. Each tumor type (lung, liver, pancreatic, kidney/adrenal) aims to include 15 cases. Informed Consent: Patients are required to sign informed consent before participating in the study, indicating their understanding of the procedures, risks, and benefits involved. Intervention: Enrolled patients will undergo stereotactic radiotherapy for their respective malignant tumors. During this process, fiducial markers will be implanted according to the study protocol. Monitoring: Following implantation of fiducial markers, the study will monitor adverse events associated with the procedure. This includes any complications or side effects resulting from the marker implantation process. Success Rate: The study will assess the success rate of fiducial marker implantation. This likely involves evaluating the accuracy and reliability of marker placement for guiding SBRT treatment. SBRT Treatment Error: The study will also monitor SBRT treatment errors. This involves tracking any deviations or inaccuracies in the delivery of stereotactic radiotherapy, potentially caused by issues such as improper fiducial marker placement or technical errors in treatment administration. Overall, the study aims to explore the feasibility and effectiveness of using fiducial marker-guided SBRT for treating various types of malignant tumors to assess both the safety and the efficacy with a focus on patient outcomes and treatment accuracy.