Enhancing inguinal tumor treatment outcomes with a customized 3D-printed bolus

Traditional boluses for pelvic lesions present challenges, including compromised skin dose coverage from large air gaps in treatment plans and increased uncertainties in treatment delivery due to variations in bolus fitting. This study evaluates the clinical benefits of a patient-specific, 3D-printed bolus (pBolus) in external beam radiation therapy (EBRT) for extramammary Paget's disease in the inguinal fold. A three-dimensional (3D) conformal plan utilizing the pBolus was compared to a conventional Superflab bolus (sBolus) under identical beam arrangements. The pBolus improved dose conformity by reducing air gaps in the treatment plan, and therefore, it was selected for clinical treatment. Weekly setup imaging revealed air gaps predominantly along the inguinal fold, demonstrating overall consistency in bolus fitting with minor air gap variations. Additionally, in vivo dosimetry confirmed dose accuracy. As a result, the patient achieved a favorable outcome, with no clinical evidence of disease at the follow-up visit.