Title:	Intraoperative radiation therapy (IORT) for Head and Neck Cancer
Background:	Intraoperative radiation therapy (IORT) delivers high dose therapeutic radiation to a precisely defined area in a wound bed subsequent to tumor extirpation and prior to wound closure/reconstruction. IORT offers the opportunity to irradiate/re-irradiate precisely defined regions (at high risk for recurrence) of the neck, skull base, and or upper aerodigestive tract in surgical salvage or other surgical settings, while avoiding exceeding tolerable doses to prior irradiated (or non-irradiated but radiation sensitive), uninvolved tissues. Complex functional and vascular anatomy of the head and neck region, however, presents unique technical and logistical concerns to the treatment teams interested in utilizing IORT, particularly in surgical salvage settings. We present our initial experience with IORT in the management of head and neck cancer at a multidisciplinary treatment center. Emphasis is placed on the logistics of IORT delivery and outcomes (viability and function) related to the free and pedicled tissue transfers that are necessary for the treatment and rehabilitation of the IORT patient. The potential of IORT as a component of head and neck cancer multidiciplinary care is discussed.
Method:	Data pertaining to our initial cohort of 12 patients treated with IORT for head and neck cancer is reported. We studied technical and logistical considerations of delivery of IORT to this diverse group of patients with complex head and neck surgical wounds. Viability and functional outcomes pertaining to the free and pedicled tissue transfers that were required in our patient population were assessed.
Results:	All patients had complex facial, upper aerodigestive tract, and or neck surgical wounds requiring precise IORT treatment planning prior to free or pedicled flap closure. Patients received between 1000-1200cGy IORT to their wound beds, which is the equivalent of 2000-3600cGy of conventional external beam radiation therapy (EBRT). Ten patients had squamous cell carcinoma (SCC) of the upper aerodigestive tract or cervical lymphatics, 1 patient had advanced poorly differentiated parotid carcinoma, and 1 patient had advanced cutaneous SCC of nape of neck skin. Ten patients who received IORT were treated in the surgical salvage setting for local or regionally recurrent head and neck cancer. All of these patients had received, at a minimum, EBRT to the treatment region. Two patients were treated with IORT in coordination with their initial surgical resection and subsequently received adjuvant EBRT. There were 8 free tissue transfers and 8 pedicled tissue transfers used to reconstruct surgical defects in the 12 patients subsequent to tumor extirpation and IORT. Wound breakdown occurred in 1 free and 1 pedicled tissue transfer patient respectively. One free tissue transfer patient required removal of infected hardware after uneventful wound healing.
Conclusion:	IORT can be delivered in a precise fashion to a variety of complex head and neck surgical wounds. Wound closure via free or pedicled tissue transfer is required for vital anatomy coverage and functional rehabilitation. Reconstruction utilizing free or pedicled tissue transfer in the context of IORT can be achieved with expectation of good wound healing in a majority of cases, despite heavy cumulative doses of radiation to recipient wound beds.