Immune PET and Proteomics for the Assessment of Response to Spatially Fractionated or Palliative Radiotherapy With or Without Immunotherapy

Inclusion Criteria: 1. Pathologically confirmed diagnosis of clear cell renal cell carcinoma, melanoma, cervical cancer, endometrial cancer or triple negative breast cancer. 2. Patients nnot eligible for radical treatment with radiotherapy (including stereotactic radiotherapy of the tumor in the potential planned area of irradiation in the study), chemotherapy and palliative immunotherapy in accordance with applicable national standards but who qualify for palliative radiation treatment 3. General condition according to Karnofsky scale: 60-100 4. Patients with tumor (index lesion) larger than 5 cm in size that can be irradiated with either SHORT or SFRT technique (presence of other tumors that may be independently treated locally is not an exclusion criterion) 5. The tumor may be assessed using iRECIST 6. Age over 18 years 7. Granted written, informed consent to participate in the research experiment 8. No contraindications to treatment with Pembrolizumab (according to the information provided in the product characteristics). 9. Expected survival time over 6 months. Exclusion criteria 1. Lack of consent to participate in the experiment 2. Contraindications to Pembrolizumab according to the product characteristics 3. Pregnancy and lactation 4. Inability of the patient to cooperate, including claustrophobia that prevents imaging tests from being performed as planned. 5. Women of childbearing potential who are unwilling or unable to use an acceptable method of contraception to avoid pregnancy throughout treatment and for 5 months after its completion. 6. Condition after organ transplantation