Dosimetric Impact of Beam Configuration and Tumor Geometry on 3D-Conformal Therapy with Electromagnetic Radiation for Hepatocellular Carcinoma

This phantom study evaluated the impact of tumor geometry and treatment parameters on dose distribution for hepatocellular carcinoma using three-dimensional conformal therapy with electromagnetic radiation. A CT simulation phantom was used to model spherical tumors of varying sizes and locations. We analyzed dosimetric outcomes for plans using 3, 4, and 6 electromagnetic radiation fields, with and without wedge filters. Plan quality significantly deteriorated for large and centrally located tumors, which exhibited poor target coverage and conformity. Conversely, small, peripheral tumors were treated effectively. Wedge filters improved conformity for large tumors but had minimal impact on central tumors. While 3D-CRT is a viable option for small, peripherally located HCC, it has significant limitations for large or central tumors. These findings provide a dosimetric rationale for prioritizing advanced techniques like IMRT or SBRT for these more challenging cases.