A phantom study investigating effective strategies for reducing fetal dose in pregnant patients with head and neck cancer.

Purpose: To measure the out-of-field doses for various treatment planning techniques and assess the impact on fetal dose with and without the use of custom shielding.

Materials And Methods: A total of six treatment plans were generated with different treatment techniques such as 3-dimensional conformal radiation therapy (3DCRT), intensity modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT), utilizing both 6 MV flattened beams and flattening filter-free (FFF) beams. The measurements were carried out both out-of-field at the surface and at depth to assess the dose reduction achieved by removing the flattening filter and incorporating shielding.