This study aims to perform ⁶⁸Ga-DOTA-mPNE PET/CT imaging in patients with clinically suspected or confirmed malignant tumors, in order to evaluate tracer uptake in lesions and analyze CD73 expression levels. In a subgroup of up to 10 participants, dynamic PET/CT imaging will be conducted for up to 90 minutes post-injection to assess the tracer's biodistribution and pharmacokinetic properties.Correlation analyses with relevant clinical indicators (such as pathology, immunohistochemistry, and molecular markers) will be carried out to further assess the diagnostic performance and clinical value of ⁶⁸Ga-DOTA-mPNE PET/CT in guiding tumor diagnosis and treatment. This study is expected to provide a novel molecular imaging tool for malignancies and offer clear, intuitive PET/CT-based evidence to support clinical diagnosis, differential diagnosis, and therapeutic decision-making.

Inclusion Criteria:

1. Age ≥18 years, with an expected survival of ≥12 weeks.
2. No prior radiotherapy or chemotherapy; eligible for surgery or biopsy to obtain pathological diagnosis.
3. At least one measurable target lesion according to RECIST version 1.1 (Response Evaluation Criteria in Solid Tumors).
4. Written informed consent obtained and able to comply with follow-up requirements.

Exclusion Criteria:

1. Severe hepatic or renal dysfunction.
2. Women who are planning to conceive, currently pregnant, breastfeeding, or intend to have children during the study period are not eligible. Fertile participants must use effective contraception during the study.
3. Unable to lie flat for 30 minutes.
4. Refusal to participate in this clinical study.
5. Claustrophobia or other psychiatric disorders.
6. Any other condition deemed unsuitable for study participation by the investigator.