Dosimetric Comparison Using an Intraoral Stent during Volumetric-modulated Arc Therapy in a Patient with Carcinoma of the Tongue

A BSTRACT A 47-year-old man diagnosed with carcinoma of the tongue and postsurgery was planned for adjuvant radiotherapy. He was simulated for radiotherapy with or without an acrylic intraoral stent (IOS). Two different radiotherapy treatment plans with volumetric-modulated arc therapy were prepared. A dosimetric comparison for doses to target volume and normal structures was done between these two plans. The use of an IOS reduced the maximum dose, the minimum dose, and the mean dose (D mean ) of palate by 6%, 91%, and 66%, respectively. The D mean for lip was reduced by 21%. There was no difference in the dose coverage for the planning target volume or other organs at risk. This case report shows the significant effectiveness of an IOS in reducing doses to the OARs in a patient of tongue cancer treated with radiotherapy using a volumetric-modulated arc therapy technique after surgery.