Can Fluorine-18-Fluorodeoxyglucose Positron Emission Tomography Be Used As a Useful Method to Evaluate the Treatment Response to Neoadjuvant Therapy Combined With Sorafenib and Anti-VEGF in Children Diagnosed With Metastatical Bone Sarcoma?
BACKGROUND
The prognosis is still poor for patients with a metastatic bone tumor and new treatment approaches (anti-VEGF and tyrosine kinase inhibitors vs) are therefore needed.


OBJECTIVE
The aim of our study was to evaluate how the primary and metastatic lesions of our patients with a bone tumor were affected by these treatments and to determine the importance of the 18F-FDG PET method.


METHODS
Twenty metastatic bone tumor cases were included. Sorafenib and anti-VEGF were added to the standard treatment in cases with widespread metastatic disease at diagnosis or after neoadjuvant chemotherapy showing less than 90% tumor necrosis in the surgical sample. Positron emission tomography (PET) imaging was performed at diagnosis, the preoperative period following neoadjuvant chemotherapy, during postoperative follow-up, and when treatment was discontinued.


RESULTS
The primary treatment region median SUVmax level decreased from 7.35 to 2.5 in the living patients (n = 16) while there was no significant decrease in the patients who succumbed to the disease (P < 0.001). Comparison of the pre- and post-treatment metastasis region median SUVmax levels in patients with metastatic involvement showed a decrease from 2.1 to 0 in the surviving patients but only from 4.8 to 3.2 in the deceased patients (P < 0.01). Survival results indicated that 28.6% of the patients receiving classical treatment only died while all the patients receiving additional sorafenib and anti-VEGF survived.


CONCLUSIONS
18F-PET may be a useful technique before and during the follow-up of neoadjuvant treatment in pediatric metastatic bone tumor patients. The addition of sorafenib and anti-VEGF to classical treatment has a favorable contribution to the response and therefore the survival duration.
Department of Pediatric Oncology, School of Medicine, Ankara University, Ankara, Turkey.
Nurdan
N
Tacyildiz
Department of Pediatric Oncology, School of Medicine, Ankara University, Ankara, Turkey.
Hikmet Gulsah
HG
Tanyildiz
Department of Pediatric Oncology, School of Medicine, Ankara University, Ankara, Turkey.
Handan Ugur
HU
Dincaslan
Department of Pediatric Oncology, School of Medicine, Ankara University, Ankara, Turkey.
Gulsan
G
Yavuz
Department of Pediatric Oncology, School of Medicine, Ankara University, Ankara, Turkey.
Emel
E
Unal
Department of Nuclear Medicine, School of Medicine, Ankara University, Ankara, Turkey.
Elgin
E
Ozkan
Department of Nuclear Medicine, School of Medicine, Ankara University, Ankara, Turkey.
Cigdem
C
Soydal
Department of Nuclear Medicine, School of Medicine, Ankara University, Ankara, Turkey.
Ozlem
O
Kucuk
Department of Orthopedics, School of Medicine, Ankara University, Ankara, Turkey.
Yusuf
Y
Yildiz
Anti-VEGF; Bone Tumors; PET; Sorafenib