IMPT CTV

Originally, this model was meant for non-robust optimization. However, we have demonstrated that it can also be applied for robust optimization.

This model is designed to be used for treatment plans for locally advanced head and neck cancer treated with a simultaneously integrated boost (SIB) using 3-field intensity modulated proton therapy (IMPT), where the elective nodal PTV is bilateral. The model aims to minimize the mean dose to the individual salivary glands, individual swallowing structures and the oral cavity. The plans used for the model were a mixture of locally advanced larynx, hypopharynx, oral cavity and oropharynx cancer, treated in 35 fractions to a total dose of 70Gy for the boost PTV and 54.25Gy for the elective PTV. Although the plans used in the model had only one boost level, the model would also work for three dose levels (although this would require some manual adaptation of dose-volume objectives for the PTVs).

All 50 cases used to train the model and those to validate the model were planned using a Y-shaped field setup: one posterior field with gantry at 180°, and 2 oblique anterior fields with gantry angles between 30-55° and between 305-330°. The gantry angles of the oblique fields could be tuned a bit depending on the orientation of the parotid glands and that shape of the PTV, based on the experience of the planner. We did not perform a gantry angle optimization for the plans.

_{Any reference to a "plan study" are simply what the organizers call each case and may not be a "study" in the FDA sense as they may not have been published in a peer reviewed journal.
Varian does not provide medical advice and these are illustrative examples only.
Leading plans by expert planner. Your results may vary.}