Resectability assessment of head and neck cancer - PET/MR versus PET/CT

Objectives To compare the diagnostic accuracy of PET/MR with PET/CT for the resectability of head and neck cancer.

Methods This prospective study was approved by the institutional review board and by national government authorities. Sequential contrast-enhanced PET/CT-MR was performed in 178 patients (136 males, median age 65 years, range 24 - 91 years) referred for the staging or re-staging of head and neck cancer. Tumors were assessed with PET/CT and PET/MR for the presence of resectability-defining factors: T4b status (mediastinal invasion, invasion of the prevertebral space, vascular encasement), and another eight findings that would imply obstacles for surgical cure (invasion of the laryngeal cartilage, invasion of the pre-epiglottic fat pad, perineural spread, orbital invasion, bone infiltration, skull base invasion, dural infiltration, invasion of the brachial plexus).

Results 117 of 178 patients were excluded due to absence of tumor at the time of imaging, 3 were lost to follow-up. In the remaining 58 patients, the sensitivity/specificity/accuracy of resectability-defining factors of PET/CT and PET/MR was 0.92/0.99/0.98 and 0.98/0.99/0.99 (p = 0.727), respectively, per lesion, and 0.96/0.87/0.91 and 0.96/0.90/0.93 (p = 0.687), respectively, per patient.

Conclusions Although no significant differences were found between PET/MR and PET/CT, there was a trend towards higher accuracy of PET/MR for the resectability assessment of head and neck cancer.