title: Assessment of the viability of microvascularized bone grafts after mandibular reconstruction by means of bone SPET and semiquantitative analysis.
abstract: The purpose of this study was to investigate the value of bone scintigraphy including single-photon emission tomography (SPET) and semiquantitative analysis for the assessment of graft viability following microvascularized bone transplantation. We evaluated 60 scintigraphic studies of 36 patients with 39 bone grafts. Thirty-four investigations were performed 6-11 days (early bone scans) and 26 up to 11 months (late bone scans) after mandibular reconstruction. After administration of 550 MBq technetium-99m methylene diphosphonate, planar scintigrams and a SPET study were performed. The data were reconstructed iteratively. Scans were evaluated visually and semiquantitatively by a region of interest technique using the ratio between transplant and cranium (T/C). Patients with uncomplicated healing showed a T/C ratio >1.0 in early and late bone scans. In cases with necrosis, the T/C ratio was below 1.0 when performing early bone scans. However, in late bone scans, some patients with necrosis showed a slightly increased uptake and a T/C ratio >1.0. The data demonstrate that as early as 6-11 days after mandibular reconstruction, increased tracer uptake proves that the surgery has been successful and indicates a normal healing process. Especially in the early bone scans no false-positive or false-negative results were observed and the T/C ratio clearly differentiated between vital and non-vital bone grafts. At later times false-positive findings could be observed; these were, however, rare because of the significantly higher tracer uptake of the healthy grafts when compared with completely or partially necrotic transplants.
authors.affiliation: Clinic of Radiotherapy and Nuclear Medicine, Medical University of Lübeck, Germany.
authors.forename: I
authors.initials: I
authors.lastname: Lauer
authors.forename: N
authors.initials: N
authors.lastname: Czech
authors.forename: J
authors.initials: J
authors.lastname: Zieron
authors.forename: P
authors.initials: P
authors.lastname: Sieg
authors.forename: E
authors.initials: E
authors.lastname: Richter
authors.forename: M
authors.initials: M
authors.lastname: Baehre
mesh_terms: D016025:Bone Transplantation; D006085:Graft Survival; D006801:Humans; D008334:Mandible / Q000000981:diagnostic imaging* / Q000601:surgery*; D009336:Necrosis; D019275:Radiopharmaceuticals; D019651:Plastic Surgery Procedures; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019275:Radiopharmaceuticals