Evaluation of the accuracy of computer-assisted techniques in the interstitial brachytherapy of the deep regions of the head and neck.

Purpose: We sought to investigate the feasibility and accuracy of computer-assisted techniques in the interstitial brachytherapy of the deep regions of the head and neck.

Materials And Methods: A computer-assisted brachytherapy workflow was applied to 10 patients with tumors in the deep regions of the head and neck. Based on the brachytherapy treatment preplan, we constructed a digital stereotactic model to accurately transfer the virtual plan into the navigation system, and subsequently printed the individual templates. The navigation system and the individual template were combined together to visualize and guide brachytherapy needle implantation. Preoperative and intraoperative image data were reconstructed and registered to measure and analyze the needle deviation.

Results: A total of 58 needles were successfully inserted in 10 patients with the guidance of computer-assisted techniques and a mean deviation of 5.2 mm. The inserting trajectories and depths of the needles were as follows: from the parotid and masseter regions to the infratemporal fossa or skull base, the range was 15.7-74.6 mm; from the submandibular and retromandibular regions to the infratemporal fossa or skull base, the range was 15.6-70.6 mm; from the infraorbital region to the pterygomandibular region, the range was 63.7-69.7 mm; and from the periorbital region to the intraorbital region, the range was 47.6-61.8 mm. The dose distribution met the treatment requirement well.

Conclusions: The computer-assisted interstitial brachytherapy workflow was proven to be feasible and accurate for the deep regions of the head and neck.