This is an open-label, single-arm, Phase II investigator-initiated trial of hypofractionated radiotherapy combined with PD-L1 inhibitor sequential GM-CSF and thymopentin for treatment of elderly patients with advanced solid tumors, when the HER-2 positive patients are treated with extra antibody-drug conjugate.

Inclusion Criteria:

• Aged 75 years and above
• Standard treatment is ineffective (disease progresses after treatment) or locally advanced or metastatic malignant solid tumor patients who cannot tolerate standard therapy, cannot receive or do not have standard therapy
• ECOG(Eastern Cooperative Oncology Group) performance is 0-3
• Life expectancy greater than 3 months
• serum aspartate transaminase (AST) and serum alanine transaminase (ALT) ≤3.0*ULN, or AST and ALT≤5*ULN with hepatic metastasis; Total serum creatinine ≤1.5*ULN
• Signed informed consent form

Exclusion Criteria:

• Current pregnancy or lactation
• History of other malignant tumors within 5 years prior to dose administration, expect for#malignancies that can be cured after treatment (including but not limited to adequately treated thyroid cancer, cervical carcinoma in situ, basal or squamous cell skin cancer)
• Uncontrolled epilepsy, central nervous system diseases or mental illness
• arrhythmia, congestive heart failure, or greater than or equal to Class 2 congestive heart failure as defined by the New York Heart Association Functional Classification, or history of myocardial infarction unstable angina, or acute coronary syndrome within 6 months prior to enrollment in the study
• Received allogeneic hematopoietic stem cell transplantation or solid organ transplantation
• Other serious, uncontrolled concomitant diseases that may affect protocol compliance or interpretation of outcomes, including active opportunistic infections or advanced (severe) infections, uncontrolled diabetes
• Allergic to any of the ingredients used in the study
• A history of immunodeficiency, including HIV positive or other acquired or congenital immunodeficiency disease, or a history of organ transplantation, or other immune-related disease requiring long-term oral hormone therapy
• Acute and chronic tuberculosis infection
• Other disorders with clinical significance according to the researcher's judgment