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. objectives: 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. patients and 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.