This study is a Compassionate clinical study for the treatment of Malignant Tumors. The primary endpoint of the study is to assess the frequency, severity and causality of acute adverse events related to the DaRT treatment. Adverse events will be assessed and graded according to Common Terminology and Criteria for Adverse Events (CTCAE) version 5.0. The secondary endpoint is to assess the tumor response to DaRT treatment assessed using the Response Evaluation Criteria in Solid Tumors (RECIST) (Version 1.1) 3 months after DaRT seed insertion.