Inclusion Criteria:

• Patients with recurrent cutaneous SCC histologically confirmed

• Histopathological confirmation within 6 months of enrollment provided no tumor treatment occurred between the biopsy and enrollment

• Immunocompromised (having a weakened immune system) patients due to any primary or secondary immunodeficiencies (excluding diabetes)

• Measurable disease according to RECIST v 1.1.

• Patient able and willing to undergo multiple CT scans

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

• Single lesion per subject.

• Patient not indicated or refused curative surgery or standard radiation.

• Targeted lesion must be technically amenable for complete coverage (including margins) by the DaRT seeds. Targets will be deemed technically amenable for complete coverage if there are entry and exit vectors for placement that are not hindered by bone or major vessels or other vital organs (eg. eye) as decided by treating physician and sponsor.

• Interstitial implant indication validated by multidisciplinary team.

• ECOG Performance Status ≤2.

• Life expectancy ≥12 months.

• Subjects male/ female ≥18.

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

• Patients, male and female, with reproductive potential (including women who are menopausal for less than a year and not surgically sterilized), must practice acceptable effective methods of birth control, such as barrier methods, condom or diaphragm with spermicide or abstinence. Birth control should be continued for 1 year after the DaRT insertion visit.

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

• Blood tests values:

  • Platelets ≥100,000 mm3

  • Total bilirubin ≤ 1.5xULN

  • AST ≤2.5xULN

  • SGOT ≤2.5xULN

  • SGPT ≤2.5xULN

  • Alkaline Phosphatase ≤2.5xULN

  • Creatinine Clearance ≥30 ml/min.

  • INR or Prothrombin time ≤1.5xULN

Exclusion Criteria:

• Distant or nodal metastatic disease (according to the TNM staging system – N+ or M1 patients are excluded).

• T4 disease or perineural spread of disease

• Mucosal, vulvar, anal and penile SCC.

• Inability to fully cover the entire volume with DaRT seeds

• Inability to place DaRT seeds into tumor due to inaccessibility by presence of bones or major vessels or vital organs

• Inability or unwillingnessto undergo multiple CT scans

• Patients receiving any of the following within 4 weeks of enrollment:

  • Antineoplastic systemic chemotherapy or biological therapy

  • Immunotherapy

  • Investigational agents other than the study intervention

  • Radiation therapy to the area of the current disease

  • Live vaccines within 30 days prior to the first dose of trial treatment and while participating in the trial.

• Longest tumor diameter >7 cm.

• Tumor with keratoacanthoma histology.

• Known hypersensitivity to any component of treatment.

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

• Any medical or Psychiatric illness, which in the opinion of the investigator would compromise the patient's ability to tolerate treatment and to adhere to the clinical trial protocol.

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

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

• Volunteers participating in another interventional study in the past 30 days which might conflict with the endpoints of this study or the evaluation of response or toxicity of DaRT.

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

• Patients do not agree to use adequate contraception (vasectomy or barrier method of birth control) prior to study entry and for 1 year after the DaRT insertion visit.

• Breastfeeding or pregnant women

• Tattoos scars, body jewelry (e.g., nose rings) or other identifying marks which cannot be adequately hidden on digital photos or other identifying marks which cannot be adequately hidden on digital photos

Note: Other protocol defined Inclusion/Exclusion Criteria may apply.

Eligibility last updated 11/05/2025. Questions regarding updates should be directed to the study team contact.