Non-invasive Measurement of PD-L1 Levels With Positron Emission Tomography (PET) in Head and Neck Malignancies and Intracranial Metastases

Inclusion Criteria for Head and Neck Cancer:

* Patients with resectable squamous cell carcinoma of the oropharynx (HPV positive and HPV negative).
* Resectability will be confirmed by a surgical co-investigator.
* If available, HPV-association determined by institutional p16 testing (CINtec antibody demonstrating strong and diffuse nuclear and cytoplasmic staining is at least 70% of cells).
* Absolute neutrophil count (ANC) \> 1500/microliter, absolute lymphocyte count (ALC) \>1000/microliter, hemoglobin \> 9 g/dl, platelets \> 100,000/microliter.
* aspartate aminotransferase (AST) and alanine transaminase (ALT) \< 5 x upper limit of normal. Bilirubin \< 1.5 x upper limit of normal.
* Albumin \> 0 g/dl.
* Creatinine \< 5 x upper limit of normal.
* Women of child-bearing potential must have a negative serum pregnancy test within 7 days prior to treatment

Inclusion Criteria for Brain Metastases:

* Patients with brain metastases
* Tumor size equal or greater than 1 cm
* Resectability or need for laser interstitial thermal therapy (LITT) will be confirmed by a surgical co-investigator.
* Absolute neutrophil count (ANC) \> 1500/microliter, absolute lymphocyte count (ALC) \>1000/microliter, hemoglobin \> 9 g/dl, platelets \> 100,000/microliter
* AST and ALT \< 5 x upper limit of normal. Bilirubin \< 1.5 x upper limit of normal.
* Albumin \> 0 g/dl.
* Creatinine \< 5 x upper limit of normal.
* Women of child-bearing potential must have a negative serum pregnancy test within 7 days prior to treatment

Exclusion Criteria for Head and Neck Cancer:

* Medical contraindication to surgery.
* Full dose anticoagulation.
* Concomitant invasive malignancy, or malignancy within 2 years except for hormonally responsive breast or prostate cancer, resected non-melanoma skin cancer, resected uterine cervical carcinoma.
* Inability to give informed consent.
* Prior systemic therapy, radiation or gross resection for the tumor under study.
* Women may not be pregnant or breast-feeding.
* Receipt of other systemic therapy including investigational agents, radiation or gross resection for treatment of the tumor under study.

Exclusion Criteria for Brain Metastases:

* Medical contraindication to brain surgery.
* Full dose anticoagulation.
* Inability to give informed consent.
* Women may not be pregnant or breast-feeding.