Evaluation of [18F]AlF-NOTA-PCP2 PET/CT for PD-L1 Detection in Malignant Tumors

Inclusion Criteria:

* Signed informed consent obtained.
* Age ≥ 18 years, any gender.
* Pathologically confirmed malignant tumors, including:
* Glioblastoma
* Head and neck squamous cell carcinoma
* Non-small cell lung cancer
* Esophageal cancer
* Detectable PD-L1 expression in tumor tissue (based on immunohistochemistry or biopsy).
* Measurable disease with at least one residual tumor lesion.
* ECOG performance status of 0-1.
* No contraindications to \[18F\]AlF-NOTA-PCP2 PET/CT imaging.
* Willing and able to comply with study procedures and follow-up visits.

Exclusion Criteria:

* Participation in another interventional clinical trial.
* Failure to recover from toxic effects or complications of prior interventions (≤ grade 1 or baseline levels, excluding fatigue or hair loss).
* Pregnant or breastfeeding women.
* Severe or uncontrolled systemic diseases, including:
* Major, symptomatic arrhythmias or significant ECG abnormalities (e.g., complete left bundle branch block, second-degree or higher heart block, or ventricular arrhythmias).
* Unstable angina or congestive heart failure (NYHA class ≥ 2).
* Any arterial thrombotic or embolic events within 6 months before enrollment (e.g., myocardial infarction, cerebrovascular accident, transient ischemic attack).
* Active or uncontrolled infections requiring systemic treatment.
* Severe psychiatric disorders affecting study participation.
* Any medical history, laboratory abnormality, or condition that may:
* Interfere with study results.
* Affect patient participation.
* Pose an unacceptable risk as determined by the investigator.
* Women of childbearing potential without a negative pregnancy test prior to study entry.
* Known allergy or hypersensitivity to \[18F\]AlF-NOTA-PCP2 or any component of the radiopharmaceutical.