In cervical cancer radiation therapy, an adaptive strategy is required to compensate for interfraction anatomical variations in order to achieve adequate dose delivery. In this thesis, we have aimed at optimizing adaptive radiation therapy in cervical cancer to improve treatment efficiency and reduce radiation-induced toxicities.First, the clinically implemented adaptive strategy was described and the dosimetric consequences of this adaptive strategy compared to conventional non-adaptive radiation therapy were demonstrated (chapter 2). This adaptive strategy can be improved by implementing our proposed (semi-)automatic bladder segmentation method on CBCT imaging for automatic plan selection purposes (chapter 3).Compared to the conventionally used X-rays, protons hold the promise of limited dose delivery to surrounding organs and the application of proton therapy can decrease the delivered dose to these organs. First, the efficiency of proton therapy delivery was improved by selecting the optimal beam configuration in cervical cancer proton therapy (chapter 4). Next, the application of adaptive proton therapy in cervical cancer was described and the dosimetric advantages of adaptive proton therapy compared to adaptive photon therapy were demonstrated (chapter 5).Adaptive radiation therapy can be further optimized by improving the target volume definition strategy. The conventional target definition strategy was adapted by excluding the non-invaded part of the uterine body using MRI. To safely rely on these MRI-based definitions, the tumor definition accuracy was validated using pathology data and deformable image registration (chapter 6). Next, the dosimetric consequences of MRI-based target volumes were compared with results using the conventional target volumes (chapter 7).