To utilize the [68Ga]Ga-THP-PDL1-3 molecular probe to non-invasively detect PD-L1 expression in primary and metastatic lesions of patients with solid tumors. Furthermore, to assess the heterogeneity of PD-L1 expression within the same lesion and across different lesions, and to observe changes in PD-L1 expression during the course of treatment. This approach aims to facilitate patient screening, therapeutic monitoring, and early warning of drug resistance and/or recurrence or metastasis in the treatment of solid tumors with high PD-L1 expression, ultimately enabling personalized targeted therapy in oncology.

Analysis plan: 1. recruit 10 participants to analyze preliminary pharmacokinetic/first-in-human dose (FIH), major organ distribution and tumor uptake information via whole-body PET/CT imaging; 2. recruit 20-30 participants to analyze in vivo safety and tumor targeting information; and 3. recruit all participants for a final summary.

Inclusion Criteria:

1. Age 18-70 years, ECOG score 0 or 1;
2. Patients with solid tumors;
3. Presence of measurable lesions on imaging examinations;
4. Expected survival ≥12 weeks.

Exclusion Criteria:

1. Severe hepatic or renal dysfunction;
2. Women who are planning pregnancy, pregnant, or breastfeeding;
3. Unable to remain in supine position for 30 minutes;
4. Refusal to participate in this clinical study;
5. Diagnosis of claustrophobia or other psychiatric disorders;
6. Other conditions deemed by the investigator as inappropriate for participation in the trial.

In accordance with the ICMJE data-sharing guidelines and Chinese data-privacy laws, raw clinical and imaging data were not publicly available to prevent compromise of patient privacy. However, the corresponding author will share deidentified patient-level data, imaging parameters (SUV values), and study protocol details if reasonably requested by the requestor.

Data access will be granted through a secure data sharing agreement for a period of 3 years after publication.

Applicants must provide a methodologically sound research plan and obtain approval from their institutional ethics committee.