Functional evaluation of microvascular free flaps with positron emission tomography

SummaryBackgroundThe aim of this study was to assess blood flow (BF) of microvascular free flaps studied with positron emission tomography (PET) in patients with head and neck squamous cell cancer (HNSCC) undergoing major radical surgery 3–4 weeks after high-dose radiotherapy.MethodsFive patients underwent resection of the HNSCC of the oral cavity followed by microvascular reconstruction with a radial forearm flap. Regional BF in oral and neck tissues was measured with PET using radiolabelled water ([15O]H2O) twice (1–2 and 12–14 days, respectively) following radical surgery.ResultsIn the first postoperative PET study, the median BF in the cutaneous flap area was 5.1 mL/100 g/min, and in the muscle contra-lateral to the recipient site 19.9 mL/100 g/min. A low flap-to-muscle BF ratio appeared to correlate with circulatory incongruity, and thus with poorer flap success. The follow-up study on the second postoperative week supported the results of the primary PET scan.ConclusionsThis pilot study suggests that PET using [15O]H2O is a feasible method to quantitatively evaluate BF of the whole free flap in patients operated on for oral HNSCC.