Predicting the outcome of distraction osteogenesis by 3-phase bone scintigraphy.
Distraction osteogenesis is an effective method for lengthening long bones and filling bone defects that result from bone resection. Insufficiency of bone consolidation in the distraction segment is problematic. In this study, we examined whether 3-phase bone scintigraphy can predict the outcome of distraction osteogenesis. We also investigated the effects of chemotherapy and surgical treatment on distraction osteogenesis.


METHODS
We performed 3-phase bone scintigraphy on 60 patients (9 high-grade malignant bone tumors as group A, 11 low-grade malignant or benign tumors as group B, 40 nontumoral conditions as group C) with distraction osteogenesis at the lengthening phase of the long bones. By setting the region of interest on the distraction segment and contralateral normal area, we calculated the perfusion index (PI), the uptake ratio of the blood-pool image (BPR), and the uptake ratio of the delayed image (DR). Patients were classified into poor and good consolidation groups from the radiographic findings of the distraction segment.


RESULTS
Good to fair correlations were obtained between the PI and BPR, the PI and DR, and the BPR and DR (r = 0.65, 0.45, and 0.57, respectively). The PI and BPR indicated no significant differences among group A-C (1.7 +/- 0.6, 2.1 +/- 0.7, and 1.8 +/- 0.8 in PI, respectively; 1.8 +/- 1.1, 1.9 +/- 0.5, and 2.0 +/- 0.7, in BPR, respectively). The DR of group A (2.4 +/- 1.2) was significantly lower than that of group B (6.3 +/- 1.8; P = 0.001) and group C (5.9 +/- 2.8; P < 0.001). Eleven patients were classified in the poor consolidation group. The other 49 patients showed good consolidation. The poor consolidation group showed lower values in all indices obtained by 3-phase bone scintigraphy than the good consolidation group. The optimal cutoff levels, sensitivity, specificity, and accuracy of each index for detection of patients with poor consolidation were as follows: 1.1, 36%, 90%, and 80% in the PI, respectively; 1.2, 55%, 94%, and 87% in the BPR, respectively; and 2.2, 82%, 96%, and 93% in the DR, respectively.


CONCLUSIONS
Three-phase bone scintigraphy is a promising method for the assessment of distraction osteogenesis. The delayed image of 3-phase bone scintigraphy, especially, is an excellent modality for predicting the outcome of distraction osteogenesis.
Kawano
Masaya
M
Department of Biotracer Medicine, Kanazawa University Graduate School of Medical Sciences, Kanazawa, Ishikawa, Japan. mkawano-circ@umin.ac.jp
Taki
Junichi
J
Tsuchiya
Hiroyuki
H
Tomita
Katsuro
K
Tonami
Norihisa
N
D000293:Adolescent; D000328:Adult; D001847:Bone Diseases / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery / Q000628:therapy; D001842:Bone and Bones / Q000098:blood supply / Q000000981:diagnostic imaging*; D005260:Female; D015902:Gamma Cameras; D006801:Humans; D008297:Male; D010012:Osteogenesis; D019857:Osteogenesis, Distraction; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D013669:Technetium Tc 99m Medronate; D016896:Treatment Outcome
D019275:Radiopharmaceuticals; D013669:Technetium Tc 99m Medronate