A Clinical Study to Assess the Efficacy and Safety of Alpha DaRT224 for the Treatment of Patients With Recurrent Cutaneous Squamous Cell Carcinoma

Inclusion Criteria:

1. Patients with recurrent cutaneous SCC histologically confirmed who have failed atleast first line standard of care therapy who are not indicated for surgery andstandard radiation therapy, or non alpha radiation brachytherapy technologies, andfor whom no curative systemic treatment is available

2. Central histopathological confirmation within 6 months of enrollment provided notumor treatment occurred between the biopsy and enrollment

3. Measurable disease according to RECIST v 1.1.

4. Ability to undergo a CT scan

5. Tumor size ≤7 cm, at the longest diameter.

6. Single lesion per subject.

7. Targeted lesion must be technically amenable for complete coverage (includingmargins) by the DaRT seeds.Targets will be deemed technically amenable for completecoverage if there are entry and exit vectors for placement that are not hindered bybone or major vessels or other vital organs (eg. eye).

8. Interstitial implant indication validated by multidisciplinary team.

9. Eastern Cooperative Oncology Group (ECOG) Performance Status ≤2.

10. Life expectancy ≥12 months.

11. Subjects male/ female ≥18.

12. Willing and have the ability to provide signed Informed Consent.

13. Patients, male and female, with reproductive potential (including women who aremenopausal for less than a year and not surgically sterilized), must practiceacceptable effective methods of birth control, such as barrier methods, condom ordiaphragm with spermicide or abstinence. Birth control should be continued for 3months after the DaRT insertion visit.

14. Women with childbearing potential must provide a negative pregnancy test during thescreening period and up to V1, prior to the DaRT insertion procedure.

15. Blood tests values:

• Leucocytes ≥3000mm3,

• Absolute neutrophil count ≥1500mm3,

• Platelets ≥100,000 mm3,

• Total bilirubin ≤ 1.5xULN (upper limit of normal)

• Aspartate Aminotransferase (AST) ≤2.5xULN,

• Serum Glutamic-Oxaloacetic Transaminase (SGOT) ≤2.5xULN,

• Serum Glutamic-Pyruvic Transaminase (SGPT) ≤2.5xULN,

• Alkaline Phosphatase ≤2.5xULN.

• Creatinine ≤ 2.0xULN or Creatinine Clearance ≥60 ml/min.

• INR (International Normalized Ratio) or Prothrombin time ≤1.5xULN.

Exclusion Criteria:

1. Distant or nodal metastatic disease (according to the TNM [tumor, nodes , andmetastases] staging system - N+ or M1 patients are excluded).

2. T4 disease or perineural spread of disease

3. Previously untreated cutaneous SCC indicated for surgery or radiation.

4. Mucosal, vulvar, anal and penile SCC.

5. Inability to fully cover the entire volume with DaRT seeds

6. Inability to place DaRT seeds into tumor due to inaccessibility by presence of bonesor major vessels or vital organs

7. Inability to undergo a CT scan

8. Patients undergoing systemic immunosuppressive therapy excepting intermittent, briefuse of systemic corticosteroids.

9. Patients receiving any of the following within 4 weeks of enrollment:

10. Antineoplastic systemic chemotherapy or biological therapy

11. Immunotherapy

12. Investigational agents other than the study intervention

13. Radiation therapy

14. Live vaccines within 30 days prior to the first dose of trial treatment andwhile participating in the trial.

15. Longest tumor diameter >7 cm.

16. Tumor with keratoacanthoma histology.

17. Known hypersensitivity to any component of treatment.

18. Clinically significant cardiovascular disease e.g., cardiac failure of New YorkHeart Association class III-IV, uncontrolled coronary artery disease,cardiomyopathy, uncontrolled arrhythmia, uncontrolled hypertension, history ofmyocardial infarction in the last 12 months.

19. Any medical or Psychiatric illness, which in the opinion of the investigator wouldcompromise the patient's ability to tolerate treatment and to adhere to the clinicaltrial protocol.

20. Serious medical comorbidities that, in the opinion of the investigator, may affectsubject compliance and/or interpretation of treatment safety or effectiveness.

21. High probability of protocol non-compliance (in opinion of investigator).

22. Volunteers participating in another interventional study in the past 30 days whichmight conflict with the endpoints of this study or the evaluation of response ortoxicity of DaRT.

23. Has a known additional malignancy that is progressing or requires active treatment.Exceptions include basal cell carcinoma of the skin that has undergone potentiallycurative therapy or in situ cervical cancer.

24. Patients do not agree to use adequate contraception (vasectomy or barrier method ofbirth control) prior to study entry and for 3 months after the DaRT insertion visit.

25. Breastfeeding or pregnant women

26. Tattoos or other identifying marks which can not be adequately hidden on digitalphotos