This review explores the nuanced decision-making surrounding postoperative radiotherapy for diffuse low-grade glioma patients, emphasizing the need for individualized treatment to balance the benefits of tumor control with the risks of side effects. Radiotherapy is a cornerstone of diffuse low-grade glioma treatment, offering significant improvements in progression-free survival, but its potential for quality of life necessitates careful consideration of individual patient factors. The review delves into the radiotherapy timing, revealing that while early radiotherapy enhances progression-free survival, it does not significantly impact overall survival and may lead to severe and prolonged decline in long-term quality of life. Conversely, delayed radiotherapy may mitigate these side effects. The review advocates for a patient-centered approach, emphasizing the importance of weighing individual risks and benefits, and highlights the potential of artificial intelligence in predicting quality of life and the need to revisit previous research findings in light of the 2021 WHO (World Health Organization) classification update, underscoring the evolving nature of low-grade glioma treatment and the ongoing quest for optimal therapeutic strategies.