Feasibility Trial of Diffusing Alpha-emitter Radiation Therapy (DaRT) for Malignant Skin & Superficial Soft Tissue Tumors

* Malignant tumor of the skin or superficial soft tissue\*, ≥10 mm and ≤50 mm in longest dimension, with minimum tumor thickness of 4 mm
* \*Including, but after review by the Principal Investigator not limited to:

  * Primary malignant tumors of the skin such as keratinocytic carcinomas (basal cell carcinoma, squamous cell carcinoma), melanocytic tumors (melanoma), soft tissue tumors (cutaneous angiosarcoma or leiomyosarcoma), and neural tumors (Merkel cell carcinoma)
  * Primary malignant tumors of the superficial soft tissues such as adipocytic tumors (liposarcoma), smooth-muscle tumors (leiomyosarcoma), skeletal muscle tumors (rhabdomyosarcoma), vascular tumors (Kaposi sarcoma, angiosarcoma of soft tissue)
  * Secondary malignant tumors of the skin and superficial soft tissues such as metastases from breast cancer, lung cancer, melanoma, kidney cancer and others.
* Limited treatment options for the tumor, including:

  * Recurrent tumors that must have failed at least one standard therapy, which includes previous radiotherapy or surgery, OR
  * Tumors in patients with metastases who will not be rendered disease-free by tumor resection, OR
  * Tumors deemed inappropriate for resection by a surgeon for one of the following reasons:

    * Complete tumor resection unlikely because of tumor location or size;
    * Complete tumor resection deemed excessively morbid or deforming (e.g., requiring amputation of digit, lip, eyelid, ear);
    * Patient with medical comorbidity contraindicating surgery; or
    * Patent refusal due to anticipated morbidity
* Age \>18 years
* Eastern cooperative oncology group performance status ≤3
* Life expectancy ≥12 weeks
* Platelet count ≥50,000/mm3
* International normalized ratio of prothrombin time ≤1.8
* Creatinine ≤1.9 mg/dL

Subject Exclusion Criteria

* Contraindication to radiotherapy for skin and superficial soft tissue tumor
* Radiotherapy to the malignant skin or soft tissue tumor planned for radiotherapy within last 6 months
* Prior radiotherapy to the malignant skin or soft tissue tumor planned for radiotherapy with doses \> 60 Gy (equivalent dose in 2 Gy fractions using α/β of 8.5)
* Anticoagulation or antiplatelet medical therapy
* High probability of non-compliance with scheduled assessments as demonstrated by prior inability to complete scheduled routine clinical assessments
* Pregnancy
* Women of childbearing potential unwilling or unable to use an acceptable contraceptive method to prevent pregnancy for 1 year after brachytherapy
* Men unwilling or unable to use an acceptable contraceptive method to prevent pregnancy for 1 year after brachytherapy
* Inability to read or understand English (as QoL questionnaires are only validated in English)
* Concurrent receipt of cancer therapy which has proven effective for the malignant skin or soft tissue tumor planned for radiotherapy