Prediction of Wound Failure in Patients with Head and Neck Cancer Treated with Free Flap Reconstruction: Utility of CT Perfusion and MR Perfusion in the Early Postoperative Period

Abstract

BACKGROUND AND PURPOSE: Free flap reconstruction in patients with head and neck cancer carries a risk of postoperative complications, and radiologic predictive factors have been limited. The aim of this study was to assess the factors that predict free flap reconstruction failure using CT and MR perfusion. MATERIALS AND METHODS:This single-center prospective study included 24 patients (mean age, 62.7 [SD, 9.0] years; 16 men) who had free flap reconstruction from January 2016 to May 2018. CT perfusion and dynamic contrast-enhanced MR imaging with conventional CT and MR imaging were performed between 2 and 4 days after the free flap surgery, and the wound assessments within 14 days after the surgery were conducted by the surgical team. The parameters of CT perfusion and dynamic contrast-enhanced MR imaging with conventional imaging findings and patient demographics were compared between the patients with successful free flap reconstruction and those with wound failure as appropriate. P , .05 was considered significant.RESULTS: There were 19 patients with successful free flap reconstruction and no wound complications (mean age, 63.9 [SD, 9.5] years; 14 men), while 5 patients had wound failure (mean age, 58.0 [SD, 5.7] years; 2 men). Blood flow, blood volume, MTT, and time maximum intensity projection (P = .007, .007, .015, and .004, respectively) in CT perfusion, and fractional plasma volume, volume transfer constant, peak enhancement, and time to maximum enhancement (P = .006, .039, .004, and .04, respectively) in dynamic contrast-enhanced MR imaging were significantly different between the 2 groups.CONCLUSIONS: CT perfusion and dynamic contrast-enhanced MR imaging are both promising imaging techniques to predict wound complications after head and neck free flap reconstruction. ABBREVIATIONS: AIF ¼ arterial input function; DCE ¼ dynamic contrast-enhanced; EES ¼ extravascular extracellular space; IQR ¼ interquartile range; Kep ¼ rate transfer constant between EES and blood plasma per minute; K trans ¼ volume transfer constant between EES and blood plasma per minute; SCC ¼ squamous cell carcinoma; TME ¼ time to maximum enhancement; tMIP ¼ time maximum intensity projection; Ve ¼ EES volume per unit tissue volume; Vp ¼ fractional plasma volume

Reconstructive flap surgery in head and neck cancer patients: an interdisciplinary view of the challenges encountered by radiation oncologists in postoperative radiotherapy

“…Imaging is rarely prescribed for the suspicion of early flap failure as clinical suspicion may suffice. Early MRI might, however, be useful to assess deeper tissue damage ( 63 ).…”

“…Other changes include wound dehiscence (separation of skin edges 30%), native skin breakdown, and the presence of a pharyngocutaneous fistula or the conditions requiring re-operation such as venous congestion and ecchymosis, seroma or hematoma, infection ( 56 , 63 , 72 ). Heterotopic ossifications occur from osteogenesis from the vascularized periosteum.…”

Intracranial paragangliomas versus schwannomas: Role of dynamic susceptibility contrast perfusion and diffusion MRI

“…Recently, diffusion-weighted imaging (DWI) and perfusion MRI have been utilized for tumor differentiation, gene mutation detection, and treatment monitoring by assessing internal microstructure and vascularity of the tumors. [11][12][13][14][15][16] Paragangliomas are known to be hypervascular tumors, while schwannomas show a relatively slow enhancement pattern compared to paragangliomas. 12 Also, there are differences in internal microstructure between the two tumors and even between sporadic and NF2-related schwannomas.…”

Advanced MRI to differentiate schwannomas and metastases in the cerebellopontine angle/internal auditory canal

“…Diffusion‐weighted imaging (DWI) and dynamic contrast‐enhanced MRI (DCE‐MRI) have been used for characterization of tumor cellularity and unique microstructure, and tumor microvascularity and permeability, respectively, 11 , 12 , 13 , 14 , 15 , 16 , 17 and increasingly applied for tumor differentiation and evaluation of treatment effects. 13 , 18 , 19 , 20 The utility of DCE‐MRI for differentiation of schwannomas and meningiomas in the CPA and jugular foramen has previously been shown to be effective with promising diagnostic performances.…”