Radiation therapy is a core component of cancer treatment, used for both curative and palliative intent, alongside surgery and systemic therapies. Over the last 2 decades, external beam radiation therapy technologies have progressed from 2-dimensional (2D) to more complex techniques such as 3-dimensional (3D) conformal radiation therapy, intensity-modulated radiation therapy (IMRT), and stereotactic radiation therapy. Improved accuracy of treatment delivery has brought considerable benefits to patients, such as reduced toxicities and improved long-term outcomes.