Role of 18F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging in prediction of response to neoadjuvant chemotherapy in pediatric osteosarcoma

Jehan Ahmed Younis; Ismael Mohammed Al Antably; Manal Zamzam; Hala Taha Salem; Eman Mohammed Zaki; Omneya Ahmed Hassanian

doi:10.4103/wjnm.WJNM_52_18

Role of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography and magnetic resonance imaging in prediction of response to neoadjuvant chemotherapy in pediatric osteosarcoma

World J Nucl Med. 2019 Dec 18;18(4):378-388. doi: 10.4103/wjnm.WJNM_52_18. eCollection 2019 Oct-Dec.

Authors

Jehan Ahmed Younis¹, Ismael Mohammed Al Antably², Manal Zamzam³, Hala Taha Salem⁴, Eman Mohammed Zaki⁵, Omneya Ahmed Hassanian⁶

Affiliations

¹ Department of Oncology and Nuclear Medicine, Faculty of Medicine, Cairo University, Cairo, Egypt.
² Department of Nuclear Medicine, National Cancer Institute, Children Cancer Hospital, Cairo, Egypt.
³ Department of Pediatric Oncology, National Cancer Institute, Children Cancer Hospital, Cairo, Egypt.
⁴ Department of Pathology, National Cancer Institute, Children Cancer Hospital, Cairo, Egypt.
⁵ Department of Radiology, National Cancer Institute, Children Cancer Hospital, Cairo, Egypt.
⁶ Department of Statistics, National Cancer Institute, Children Cancer Hospital, Cairo, Egypt.

Abstract

The aim of our study was to evaluate the role of ¹⁸F-fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and magnetic resonance imaging (MRI) in prediction of response to neoadjuvant chemotherapy (NAC) in pediatric osteosarcoma (OS) patients compared to percentage of tumor necrosis after surgical excision of the tumor. Forty-six pediatric OS patients treated with neoadjuvant chemotherapy and surgery were underwent PET/CT and MRI before, after 3 cycles, and after the completion of neoadjuvant chemotherapy. Imaging parameters include maximum standardized uptake value (SUVmax1, 2, and 3), tumor liver ratio (TLR 1, 2, and 3), and MRI tumor volume (MRTV 1, 2, and 3) at initial assessment before starting NAC, after finishing three cycles and after finishing 6 cycles before tumor excision, respectively. Cutoff values of the PET/CT and MRI parameters were determined using receiver operating characteristic (ROC) curve analysis and percentage of tumor necrosis of postsurgical specimen. Fourteen patients were good responders (30.4%), with more than 90% tumor necrosis, while 31 patients were poor responders (67.4%). The results of one patient were missed. We noticed that higher sensitivity for detecting poor responders was detected by SUVmax3/1, TLR3/1, and MRTV2/1 ratio cutoff values, while higher specificity was detected by TRL2 and SUVmax3 cutoff values. ROC curve analysis of MRTV2/1 and MRTV3/1 ratio was fair in predicting poor responders. PET/CT parameters are capable of predicting histological response to NAC in OS patients with overall sensitivity and specificity higher than MRI parameters.

Keywords: 18F-fluorodeoxyglucose positron emission tomography/computed tomography; magnetic resonance imaging; neoadjuvant chemotherapy; osteosarcoma.