18F-FDG PET: early postoperative period of oro-maxillo-facial flaps.
OBJECTIVE
We addressed the feasibility of FDG-PET to differentiate between viability and non-viability in the immediate postoperative assessment of flaps (autologous microvascular anastomosed pedicled flaps) in oro-maxillo-facial surgery.


METHODS
3-7 days after surgery, FDG-PET was done in 38 patients who had received flaps for re-construction of the mandible after partial resection. The studies were done on a dedicated full ring PET-scanner (ECAT EXACT HR+, Siemens/CTI). Acquisition started between 60 and 80 min post injection. The findings of the soft tissue component of the flaps were grouped using a three point scale: (I) no defect, (II) small defects, (III) one large defect. The results of PET were compared with the clinical course for at least 3 months.


RESULTS
"No defect" on the FDG-PET study identified vi-ability of the flap and predicted normal clinical follow-up (22/38 patients). "Small defects" visualized areas of decreased perfusion and decreased glucose metabolism indicating risk of non-viability (13/38 patients); adapt-ing the postsurgical management led to delayed but uncomplicated healing of the flaps in these patients. "One large defect" demonstrated early necrosis of the flap (3/38 patients). After removal and replacement of this necrotic portion of the flap the second FDG-PET scan of these 3 patients demonstrated the uncomplicated post-operative healing.


CONCLUSIONS
FDG-PET facilitated the assessment of viability and non viability of flaps in the immediate postsurgical period, and demonstrated the usefulness of FDG-PET for postoperative care and prognosis.
Department of Radiology, Division of Nuclear Medicine, Karl-Franzens University Graz, Auenbruggerplatz 9 8036 Graz, Austria. reingard.aigner@kfunigraz.ac.at
R M
RM
Aigner
G
G
Schultes
G
G
Wolf
Y
Y
Yamashita
E
E
Sorantin
H
H
Kärcher
D000328:Adult; D000368:Aged; D001786:Blood Glucose / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008297:Male; D008339:Mandibular Neoplasms / Q000601:surgery*; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D009055:Mouth / Q000000981:diagnostic imaging / Q000601:surgery*; D011184:Postoperative Period; D019275:Radiopharmaceuticals; D019651:Plastic Surgery Procedures; D013524:Surgical Flaps; D014055:Tomography, Emission-Computed; D014945:Wound Healing
D001786:Blood Glucose; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18