This study proposes to treat metastatic non-small cell lung cancer (NSCLC) and head/neck squamous cell cancer (HNSCC) patients who are already initiating an immune checkpoint inhibitor (such as Nivolumab, Atezolizumab or Pembrolizumab) for disease treatment as per FDA approved guidelines. In these patients we will deliver a short-course radiation to a single systemic (non-CNS) site within 14 days of receiving the first dose of immune checkpoint inhibitors. This sequence allows radiation to release tumor antigens from immune inaccessible areas such as necrotic tumor or low perfusion to provide a robust anti-tumor immune response with immune checkpoint inhibitors.

The primary objective is to assess six-month progression free survival (PFS) compared to historical control.

Subjects with front-line or relapsed NSCLC or relapsed HNSCC who are intended to receive standard of care immune checkpoint inhibitors without a contraindication to Stereotactic Body Radiation Therapy (SBRT) to a single cancer deposit greater than 1 cm (metastasis or primary cancer) will be enrolled. Subjects will receive standard of care (SOC) immune checkpoint inhibitors and within 2 weeks of initiation, and will receive either:

• SBRT to target to achieve Biological Equivalent Dose (BED) > 100 Gy OR
• 30 Gy fractionated radiation therapy (RT) delivered as a 3 dimensional (3-D) dose.

The lesion choice will be made by the treating radiation oncologist and will be directed to a single malignant focus (non-CNS) that measures ≥ 1 cm. Essentially, the goals of both techniques are the same but SBRT is reserved for lesions that are readily encompassed by a single field with large RT fractions in which dose-limiting organs are within safe limits.

Inclusion Criteria:

1. Histologically proven advanced or metastatic non-small cell lung cancer or squamous cell carcinoma head and neck with tumor at least 1 cm in size.

2. Eligible for treatment with radiation therapy.

3. Prior treatment: chemotherapy or radiotherapy or surgery.

   1. Prior chemotherapy or radiation must have concluded ≥ 21 days prior to the start of study treatment.
   2. No limit is placed on prior systemic treatment, but subjects must be eligible for immune checkpoint inhibitors therapy, for an FDA approved indication.
   3. No major surgery within 14 days of start of study treatment.

4. No previous or concurrent malignancy is allowed except for adequately treated basal cell or squamous cell skin cancer, in situ cervical cancer, or other cancer for which the patient has been disease free for the past 3 years.

5. Age ≥ 18 years.

6. Life expectancy ≥ 3 months.

7. Required initial laboratory values:

   1. Absolute neutrophil count ≥ 1,000/mm3
   2. Platelets ≥ 100,000/mm3
   3. Total bilirubin ≤ 1.5 x ULN
   4. AST and ALT if no hepatic metastasis ≤ 2.5 times x ULN
   5. AST and ALT with hepatic metastasis ≤ 5 x ULN
   6. Creatinine ≤ 1.5 x ULN and Requires CrCl ≥ 60ml/min (per 24-hour urine collection or calculated according to the Cockcroft-Gault formula)

8. Non pregnant and non-nursing women. Women of childbearing potential must have a negative serum pregnancy test performed within 7 days prior to the start of treatment. Women of childbearing potential and men must agree to use adequate contraception (barrier method of birth control) prior to study entry and for the duration of study participation. Subjects should use adequate birth control for at least 3 months after the last administration of immune checkpoint inhibitors.

9. Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

1. Active clinically serious infection > CTCAE Grade 2.
2. Serious non-healing wound, ulcer or bone fracture.
3. Prior treatment with immune checkpoint inhibitors.
4. Ineligible for immune checkpoint inhibitors based on package insert of the chosen immune checkpoint inhibitor (e.g., uncontrolled immunologic disorders, active hepatitis, active colitis, active pneumonitis, uncontrolled/active hormone gland problems - including thyroid, pituitary, adrenal glands and pancreas).
5. Major surgical procedure (including craniotomy and open brain biopsy) or significant traumatic injury within 14 days prior to registration or those patients who receive a non-CNS minor surgical procedures (e.g. core biopsy or fine needle aspiration) within 3 days prior to registration. There is no waiting period for central line placement. There is a 7-day window for recovery prior to registration for patients who underwent stereotactic biopsy of the brain.
6. Participants may not have uncontrolled inter-current illness. This includes, but is not limited to: ongoing or active infection; symptomatic congestive heart failure (NYHA class III or IV); unstable angina pectoris or new onset angina that began within the last 3 months; cardiac ventricular arrhythmias requiring anti-arrhythmic therapy; or thrombotic/embolic events such as cerebrovascular accident, including transient ischemic attacks within the past 6 months. Uncontrolled hypertension defined as systolic blood pressure >150 mmHg or diastolic pressure > 90 mmHg, despite optimal medical management. Known human immunodeficiency virus (HIV) infection or chronic Hepatitis B or C. Known Grade 3 or 4 neurotoxicity.

3 years

The descriptions and grading scales found in the revised NCI Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 will be utilized for AE reporting