This book takes an in-depth look at proton therapy, an advanced radiotherapy technique using protons to treat cancer. It begins with a presentation of the fundamental principles of proton therapy and the importance of the Bragg effect, which enables tumors to be precisely targeted while preserving healthy tissue. Through clinical case studies, we examine the promising results obtained for various types of cancer, highlighting the advantages of this approach over conventional radiotherapy. The book also discusses Bragg distance calculation and modeling methods, highlighting their impact on treatment optimization. Technological innovations, such as miniaturized gas pedals and the integration of advanced imaging, are discussed, as is ongoing research into the Bragg effect. Finally, future prospects, including the integration of proton therapy with other treatment modalities, are presented, paving the way for precision medicine in the fight against cancer.