This study by the Heidelberg group reported clinical outcomes of 25 patients with uterine cervical or endometrial cancer treated with postoperative PBT. Proton radiation was delivered to a total dose of 45 to 50.4 Gy (RBE) in 5 to 6 × 1.8 Gy (RBE) fractions weekly. No patient developed gastrointestinal or genitourinary toxicity ≥grade 3, and the treatment tolerability rate was 100%. With a median follow-up time of 25.1 months, 7 patients had progressive disease. The conclusion of this study is that postoperative IMPT is a safe treatment option for cervical and endometrial cancer patients, with only low-grade acute and late toxicities.