Purpose: To evaluate the dosimetric impact of four different radiotherapy techniques for a case of left-sided breast cancer with Internal Mammary lymph Nodes (IMN) involvement. Materials and methods: To identify the best radiotherapy technique for this patient. four methods were compared: 3D Conformal Radiotherapy (3D-CRT). Volumetric Modulated Arc Therapy (VMAT). https://www.diegojavierfares.com/deal-time-Hybrid-Racing-V3-Short-Shifter-Assembly-02-06-RSX-K-Swap-flash-save/