Matthieu J. Ouvrier MD, Presenter: Nothing to Disclose

Colette Zwarthoed MD, Abstract Co-Author: Nothing to Disclose

Danielle Benisvy, Abstract Co-Author: Nothing to Disclose

Jose Benoliel PhD, Abstract Co-Author: Nothing to Disclose

Olivier Dassonville MD, Abstract Co-Author: Nothing to Disclose

Jacques Darcourt MD, PhD, Abstract Co-Author: Nothing to Disclose

The aim of this study was to compare the performance of planar bone scintigraphy (BS) and SPECT/CT in the assessment of microvascular bone grafts in mandible reconstruction 24 hours after surgery. 

Twelve mandible reconstructions were performed on 11 patients (8M/3F, 56 ± 13 y/o), 9 with cancer (squamous cell carcinoma n=5, adenoid cystic carcinoma n=3, rhabdomyosarcoma n=1) and 2 with osteoradionecrosis. Reconstruction of the mandible consisted of an autogenous microvascular bone grafting with a fibular free-flap with a skin pedicle. Fourteen planar BS and SPECT/CT were performed 24 hours after surgery. Patients were injected with 99mTc-HMDP (10MBq/kg). BS were acquired on a Siemens Symbia T2 240 minutes after injection, systematically followed by a SPECT/CT. Images were reconstructed in 3-mm slices every 2 mm. SPECT images were reconstructed using CT for attenuation correction and using iterative reconstruction. Planar and SPECT/CT BS were analyzed semi-qualitatively by two nuclear physicians. Consensus was found between the two physicians when there was a discrepancy. They were rated as certainly not viable, probably viable, equivocal, probably viable, certainly viable. Follow-up was used as gold standard.

Seven patients were free of complications, 2 had partial muscular necrosis, 1 had infectious complication but no necrosis and 1 had bone necrosis on 2 different free-flaps. Two planar BS were rated as certainly not viable, 1 probably not viable, 2 equivocal, 3 probably viable and 6 certainly viable. Three SPECT/CT were rated as probably not viable, none were rated as probably not viable nor equivocal, 4 were rated as probably viable and 7 as certainly viable. For planar BS and SPECT/CT, sensitivity was respectively 82% and 100%. Specificity was 100% for both . The level of confidence did not significantly improve but there was less indeterminate ratings with SPECT/CT than with planar BS (4 vs 6).

SPECT /CT could be a better tool 24 hours after surgery, when patients are not necessarily stable, for assessing microvascular bone grafts in mandible reconstruction, thus reducing the time of presence in the department.

SPECT/CT has better perfomance than planar BS in the assessment of microvascular bone grafts in mandible reconstruction 24 hours after surgery, when patients are not necessarily stable. 

Ouvrier, M, Zwarthoed, C, Benisvy, D, Benoliel, J, Dassonville, O, Darcourt, J, Performance of SPECT/CT Compared to Planar Bone Scintigraphy in the Assessment of Microvascular Bone Grafts in Mandible Reconstruction.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14010278.html