Base of Tongue:
This patient was planned for a definitive course of radiotherapy to base of tongue primary, the left neck operative bed, undissected left neck (in total levels IB-V on the left), and right neck levels II-V.
Initially, a simultaneous-integrated boost technique was planned to a total dose of 60Gy in 30 fractions to PTV60 (2 Gy per fraction) and a total dose of 57Gy in 30 daily fractions to PTV57 (1.9Gy per fraction) as well as a total dose of 54Gy in 30 daily fractions to PTV54 (1.8Gy per fraction).
SIB to 6000cGy consisted of 2 full-arcs and 2 partial arcs. Adding the 2 partial arcs helped me to control dose to the cord, brainstem, parotids and right submandibular gland. Additionally, I made sure the hot areas of the plan did not impact the brachial plexus.
Gross disease boost was delivered as a second fraction on each Friday with a minimum of six hours between the initial plan and the boost Rapid Arc plan.
10Gy boost in 5 fractions.
Sum DVH to 70Gy
While I was not able to meet the requirements for the left parotid and right submandibular, I was able to achieve a mean dose on the right parotid of 2760cGy with just 32% of the gland receiving greater than 3000cGy. All other requirements were within tolerance.