Radiation therapy

3D Conformal Radiation Therapy (3D-CRT) in External Beam Planning 3D Conformal Radiation Therapy (3D-CRT), also known as 3D conformal radiotherapy, is a standard and widely used technique in external beam radiation therapy (EBRT). It shapes high-dose radiation to precisely match the three-dimensional (3D) contours of a tumor while minimizing exposure to surrounding healthy tissues. This represents a major advancement over older 2D planning methods, which relied on simpler X-ray images and rectangular fields that often irradiated more normal tissue. How 3D External Beam Planning Works The process is highly precise and involves several key steps: 1. Imaging and Simulation      • Patients undergo a CT scan (often combined with MRI or PET-CT) in the exact treatment position.      • Immobilization devices (e.g., custom molds, masks, or cushions) ensure reproducibility.      • These scans create a detailed 3D model of the...