Anti-PD-L1 and SAbR for Ovarian Cancer

Screening/Baseline Procedures Assessments performed exclusively to determine eligibility for this study will be done only after obtaining informed consent. Assessments performed for clinical indications (not exclusively to determine study eligibility) may be used for baseline values even if the studies were done before informed consent was obtained. All screening procedures must be performed within 28 days prior to registration unless otherwise stated. The screening procedures include: * Informed Consent * Medical history: Complete medical and surgical history, history of infections * Demographics: Age, gender, race, ethnicity * Review subject eligibility criteria * Review previous and concomitant medications * Physical exam including vital signs, height and weight: Vital signs (temperature, pulse, respirations, blood pressure), height, weight * Performance status: Performance status evaluated prior to study entry according to Appendix #/letter. * Adverse event assessment: Baseline adverse events will be assessed. See section 6 for Adverse Event monitoring and reporting. * Hematology CBC and diff ( within 2 weeks of registration) * T 4 levels, TSH and CMP as below: Comprehensive metabolic panel (CMP) to include: albumin, alkaline phosphatase, ALT/SGPT, AST/SGOT, BUN, creatinine, electrolytes (sodium, potassium, calcium, chloride, bicarbonate), glucose, and total bilirubin. (within 2 weeks of registration)- Pregnancy test (for females of child bearing potential)( within 2 weeks of registration) * Tumor assessment:Baseline imaging by CT scan of chest , abdomen, and pelvis. Procedures During Treatment * Prior to Each Treatment Cycle * Physical exam, vital signs * Hematology * Serum chemistries * Every 8 weeks after start till end of treatment Serum TSH, pregnancy test and CT chest abdomen and pelvis 30 days after treatment termination * Physical exam, vital signs * Hematology * Serum chemistries * additional Immune co-relate lab testing: Prior to cycle 1, cycle 3, cycle 5, cycle 7 and 2 weeks post last cycle. Follow-up Procedures * For patients who are still receiving Avelumab: Subject will be followed every eight weeks (+/- 2 weeks) starting from the beginning of treatment for the first year, then every 12 weeks (+/- 2 weeks) till 2 years after last dose of drug The following procedures will be performed at each follow up: * Physical exam, PS, vital signs, medication review, AE assessment * Blood collection per time table and for labs * Radiographic imaging: Tumor assessments will be completed by the investigator using the RECIST criteria as above. * CT chest, abdomen and pelvis with IV contrast, if allowable by renal function * After that, survival information will be collected every 6 months until patient death. * For patients who have been discontinued from Avelumab : Subject will be followed 30 days from last dose (±7 days, or may be on date of discontinuation ±7 days if the date of discontinuation is more than 37 days after last dose) and then 3-4 months from last dose. The following procedures will be performed at the first two visits: * Physical exam, PS, vital signs, medication review, AE assessment * Subsequent anti-cancer treatment/s * For first visit only, or may repeat if study drug related toxicity persists: CBC w/ differential, LFTs, BUN, creatinine, fasting glucose, and TSH After that, survival information will be collected every 6 months until patient death.