The APROVE study is a prospective single-center single-arm phase-II study. Patients with cervical or endometrial cancer after surgical resection who have an indication for postoperative pelvic radiotherapy will be treated with proton therapy instead of the commonly used photon radiation. A total of 25 patients will be included in this trial. Patients will receive a dose of 45-50.4 Gray in 1.8 Gray fractions 5-6 times per week using active raster-scanning pencil beam proton radiation. Platinum-based chemotherapy can be administered if indicated. The primary endpoint of the study is the evaluation of safety and treatment tolerability of pelvic radiation using protons defined as the lack of any CTC AE Grade 3 or 4 toxicity. Secondary endpoints are clinical symptoms and toxicity, quality of life and progression-free survival. The aim is to explore the potential of proton therapy as a new method for adjuvant pelvic radiotherapy to decrease the dose to the bowel, rectum and bladder thus reducing acute and chronic toxicity and improving quality of life.