Utility of emission tomography in evaluation of mandibular bone grafts

Bone scanning, performed within 1 week postoperatively, is valuable in predicting the survival of revascularized composite flap grafts. Conventional planar scintigraphy is limited by a two-dimensional representation of three-dimensional structures. Single photon emission computed tomography (SPECT) is a technique in which a gamma camera rotates around the patient, acquires multiple projections, and with the aid of a computer, reconstructs three-dimensional representations. We wished to evaluate the potential advantages of SPECT in the assessment of mandibular graft viability and to compare it with planar scanning. These noninvasive methods of assessing the vascular supply are critical to patient management in the early postoperative period because the presence of or inability to exclude vascular compromise commands surgical exploration of the anastomosis for graft salvage. Fifteen patients who underwent mandibular reconstruction with revascularized free grafts were studied by both planar and SPECT scintigraphy. Long-term follow-up data were correlated with the outcome predicted by the scanning.