Marking of tumor resection borders for improved radiation planning facilitates reduction of radiation dose to free flap reconstruction in head and neck cancer surgery

Accurate localization of tumor resection borders is crucial for adjuvant radiotherapy. An improvement to adjuvant radiotherapy with the reduction of radiation doses to free flap reconstruction by virtual navigation procedures and titanium clips was evaluated.Thirty-three patients with oral cancer were prospectively included in the study. Following complete local excision of the primary tumor, resection borders were marked virtually using a navigation pointer and with titanium ligature clips. Postoperative delineation of tumor resection borders was examined. In five patients with microvascular free flap reconstruction a reduction of the radiation dose to the free flap reconstruction was achieved. The tumor resection borders in 30 patients were marked with titanium ligature clips. Surgical clip insertion was successful in 91%. We demonstrate a significant relationship between the reconstruction volume and the part of the target volume which will receive a reduced radiation dose. A cumulative dose of 60 Gy was administered to the target volume and a significant reduction of the administered radiation dose to the center of the flap could be demonstrated. We demonstrate an accurate delineation of the tumor resection margins. These improvements in tumor resection margin delineation allow for increased accuracy in adjuvant treatment and a reduction of radiation dose to the vascular free flap reconstruction.