The effect of neoadjuvant versus adjuvant irradiation on microvascular free flap reconstruction in sarcoma patients

BACKGROUND: Sarcoma patients often require radiation therapy in addition to surgical resection. Although neoadjuvant irradiation possesses advantages over adjuvant irradiation related to smaller doses and field sizes, existing studies suggest adverse effects on wound healing and possibly microvascular free flap success. Conversely, microvascular reconstruction may counteract some of the negative effects of irradiation by replacing irradiated tissue with well-vascularized unirradiated tissue from a distant site. METHODS: A review of sarcoma patients who underwent resection, microsurgical reconstruction, and either neoadjuvant or adjuvant irradiation was performed. RESULTS: A total of 119 patients met inclusion criteria, of which 73 underwent neoadjuvant irradiation and 46 underwent adjuvant irradiation. Sarcomas were located in the head and neck (n = 47), trunk (n = 7), upper extremity (n = 15), and lower extremity (n = 50). The rate of perioperative (≤30 days) complications was 26.9 percent, whereas the rate of late recipient-site complications was 14.3 percent. No significant differences in perioperative recipient-site (p = 0.19), donor-site (p = 1.00), or medical complications (p = 0.30) were observed between patients undergoing neoadjuvant and adjuvant irradiation. Free flap loss rates were lower in patients undergoing neoadjuvant irradiation (0 percent versus 8.7 percent, respectively; p = 0.02). Late recipient-site complications occurred less often in patients undergoing neoadjuvant radiation (6.8 percent versus 26.1 percent, respectively; p = 0.006). CONCLUSIONS: Neoadjuvant irradiation does not increase the risk of acute wound or microvascular complications when combined with free flap reconstruction, and is associated with fewer late recipient-site complications than adjuvant irradiation. These factors should be considered when determining the timing of radiation therapy in sarcoma patients undergoing oncologic resections and microsurgical reconstruction.