Impact of Neuroradiology-Based Peer Review on Head and Neck Radiotherapy Target Delineation

Example of image fusion performed at TPQA. Green crosshairs intersect over the laryngeal tumor. Rows represent the following: radiation oncology treatment planning CT scan, diagnostic PET, diagnostic MR imaging, fusion of treatment planning CT with PET, and fusion of treatment planning CT with MR imaging.

A, Alterations by subsite following HN TPQA. Light gray bars represent cases that were altered after review. Dark gray bars represent cases that were reviewed without subsequent alterations. Percentages to the right of the bars represent the fraction of cases with alterations. B, Types of treatment plan alterations. Light gray bars and data labels represent the percentage of total plans (n = 80) found to have changes by listed category. Dark gray bars represent the fraction of total plans with nonsignificant changes. PNI indicates perineural invasion; OAR, organs at risk; and DM, distant metastases. Note that x-axes were broken to reduce the width of the figure while maintaining a display of low and high values.

A, Volumetric changes in Pre-TPQA plans compared with Post-TPQA. Overall direction of GTV and CTV change. B, Volumetric changes in Pre-TPQA plans compared with Post-TPQA. Percentage of volume changes by subsite.

Treatment planning examples of TPQA changes. Red represents the pre-TPQA GTV or CTV1, and orange represents the altered post-TPQA GTV or CTV1. Yellow represents the pre-TPQA or CTV2, and blue represents the altered post-TPQA or CTV2. Changes include the following: increase in GTV for suspicion of gross disease involving the hyoid bone (A), increased GTV and CTV for pre-mastoid disease (B), expansion of CTV to include suspected PNI within the pterygopalatine fossa (C), and additional nodal GTV but decreased primary tumor GTV to spare additional laryngeal toxicity (D). PNI indicates perineural invasion.