Anti-PD-L1 and SAbR for Ovarian Cancer

Inclusion Criteria: 1. Female subjects aged ≥ 18 years. 2. Performance ECOG status of 0-2 3. Patient is able and willing to comply with protocol and study procedures for the duration of the study including undergoing treatment and scheduled visits and examinations including follow-up visits. 4. Adequate Physiologic function: * Hematologic: Absolute neutrophil count (ANC) ≥ 1.5 × 109/L, platelet count ≥ 100 × 109/L, and hemoglobin ≥ 9 g/dL (may have been transfused) * Hepatic: Total bilirubin level ≤ 1.5 × the upper limit of normal (ULN) range and AST and ALT levels ≤ 2.5 × ULN or AST and ALT levels ≤ 5 x ULN (for subjects with documented metastatic disease to the liver). * Renal: Estimated creatinine clearance ≥ 30 mL/min according to the Cockcroft-Gault formula (or local institutional standard method) 5. Pregnancy and contraception: Pregnancy test: Negative serum or urine pregnancy test at screening for women of childbearing potential. Contraception: Women of child-bearing potential and their male partners must agree to use adequate contraception (hormonal or barrier method of birth control; abstinence) prior to study entry., 6. Histologic diagnosis of recurrent epithelial ovarian ,fallopian ,peritoneal cancer 7. Patients with platinum sensitive ovarian cancer must have progressed through at least one platinum containing regimen for recurrent disease. 8. Patients with platinum resistant ovarian cancer must have progressed through at least one prior chemotherapy regimen for recurrent ovarian cancer. 9. Patients must have received at least one prior chemotherapy regimen and up to any number of prior systemic regimens including chemotherapy and molecular targeted therapy other than PD1/ PDL1/ PDL2 inhibitors. 10. Metastatic disease of at least two Non-CNS sites (including the index lesion to be treated) measurable by RECIST criteria with at least one site outside of the radiation field and evaluable by RECIST criteria for evaluation of response. 11. Ability to understand and the willingness to sign a written informed consent - Exclusion Criteria: 1. IMMUNOSUPRESSANTS: "Current use of immunosuppressive medication, EXCEPT for the following: a. Intranasal, inhaled, topical steroids, or local steroid injection (e.g., intra-articular injection); b. Systemic corticosteroids at physiologic doses ≤ 10 mg/day of prednisone or equivalent; c. Steroids as premedication for hypersensitivity reactions (e.g., CT scan premedication)." 2. AUTOIMMUNE DISEASE: "Active autoimmune disease that might deteriorate when receiving an immuno-stimulatory agent. Patients with diabetes type I, vitiligo, psoriasis, or hypo- or hyperthyroid diseases not requiring immunosuppressive treatment are eligible." 3. ORGAN TRANSPLANTATION: "Prior organ transplantation including allogenic stem-cell transplantation." 4. HIV/AIDS: "Known history of testing positive for HIV or known acquired immunodeficiency syndrome." 5. HEPATITIS: "Hepatitis B virus (HBV) or hepatitis C virus (HCV) infection at screening (positive HBV surface antigen or HCV RNA if anti-HCV antibody screening test positive)" 6. VACCINATION: "Vaccination within 4 weeks of the first dose of avelumab and while on trials is prohibited except for administration of inactivated vaccines " 7. HYPERSENSITIIVTY TO STUDY DRUG: "Known prior severe hypersensitivity to investigational product or any component in its formulations, including known severe hypersensitivity reactions to monoclonal antibodies (NCI CTCAE v4.03 Grade ≥ 3)" 8. CARDIOVASCULAR DISEASE: "Clinically significant (i.e., active) cardiovascular disease: cerebral vascular accident/stroke (\< 6 months prior to enrollment), myocardial infarction (\< 6 months prior to enrollment), unstable angina, congestive heart failure (≥ New York Heart Association Classification Class II), or serious cardiac arrhythmia requiring medication." 9. OTHER PERSISTING TOXICITIES: "Persisting toxicity related to prior therapy (NCI CTCAE v. 4.03 Grade \> 2); however, alopecia, sensory neuropathy Grade ≤ 2, or other Grade ≤ 2 not constituting a safety risk based on investigator's judgment are acceptable." 10. Other severe acute or chronic medical conditions including colitis, inflammatory bowel disease, pneumonitis, pulmonary fibrosis ,Severe COPD requiring \> 3 hospitalization in the past year Or psychiatric conditions including recent (within the past year) or active suicidal ideation or behavior; or laboratory abnormalities that may increase the risk associated with study participation or study treatment administration or may interfere with the interpretation of study results and, in the judgment of the investigator, would make the patient inappropriate for entry into this study. 11. No concomitant therapy with any of the following: IL2, interferon, or other non-study immunotherapy regimens; cytotoxic chemotherapy; immunosuppressive agents; or other investigational therapies; all such therapies must have been discontinued \>4weeks prior to registration. 12. No active TB, 13. Patients with other invasive malignancies, with the exception of non-melanoma skin cancer, who had (or have) any evidence of other cancer present within the last 5 years or whose previous cancer treatment contraindicates this protocol therapy. 14. Uncontrolled intercurrent illness including, but not limited to, ongoing or active infection, symptomatic congestive heart failure, unstable angina pectoris, cardiac arrhythmia, or psychiatric illness/social situations that would limit compliance with study requirements. 15. Patients must not be pregnant or nursing. 16. No history of prior treatment with inhibitor of PD-1 or PD-L1 or PDL2. 17. Major surgery within 2 weeks prior to registration or first dose of drug 18. Subjects who have had radiation therapy within 2 weeks prior to first dose of drug 19. Uncontrolled adrenal insufficiency or active chronic liver disease 20. Any history of CNS metastases that is not adequately treated (surgery or radiation ) \>14 days prior to registration. 21. Any condition requiring systemic treatment with either corticosteroids (\> 10 mg daily prednisone equivalent) or other immunosuppressive medications within 14 days prior to the first dose of study drug. Inhaled steroids and adrenal replacement steroid doses up to 10 mg daily prednisone equivalent are permitted (although not encouraged) in the absence of active autoimmune disease.