title: Correlation between apparent diffusion coefficient and histopathology subtypes of osteosarcoma after neoadjuvant chemotherapy.
abstract: Background Neoadjuvant chemotherapy has made limb-salvage surgery possible for the patients with osteosarcoma. Diffusion-weighted magnetic resonance imaging (DWI) has been used to monitor chemotherapy response. Purpose To correlate the apparent diffusion coefficient (ADC) values with histopathology subtypes of osteosarcoma after neoadjuvant chemotherapy. Material and Methods Twelve patients with osteoblastic (n = 7), chondroblastic (n = 4), and fibroblastic (n = 1) osteosarcomas underwent post-chemotherapy DWI before limb-salvage surgery. ADCs corresponding to 127 histological tissue samples from the 12 resected specimens were compared to histological features. Results The mean ADC value of non-cartilaginous viable tumor (38/91, ADC = 1.22 ± 0.03 × 10-3mm2/s) was significantly ( P < 0.001) lower than that of non-cartilaginous tumor cell necrosis without stroma disintegration (25/91, ADC =1.77 ± 0.03 × 10-3mm2/s), cartilaginous viable tumor (14/91, ADC = 2.19 ± 0.04 × 10-3mm2/s), and cystic areas including liquefied necrosis, blood space, and secondary aneurysmal bone cyst (14/91, ADC = 2.29 ± 0.05 × 10-3mm2/s). The mean ADC value of non-cartilaginous tumor cell necrosis was also significantly ( P < 0.001) smaller than those of viable cartilaginous tumor and cystic/hemorrhagic necrosis whereas the mean ADC values were not significantly ( P > 0.05) different between viable cartilaginous tumor and cystic/hemorrhagic necrosis. Conclusion DWI allows assessment of tumor necrosis after neoadjuvant chemotherapy by ADC differences between viable tumor and necrosis in fibroblastic and osteoblastic osteosarcomas whereas viable chondroblastic osteosarcoma has high ADC and cannot be distinguished reliably from necrosis.
authors.affiliation: 1 Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Jifei
authors.initials: J
authors.lastname: Wang
authors.affiliation: 2 Department of Medical Imaging and Interventional Radiology, Sun Yat-sen University Cancer Center, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Guangzhou, PR China.
authors.forename: Meili
authors.initials: M
authors.lastname: Sun
authors.affiliation: 3 Department of Pathology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Liu
authors.affiliation: 1 Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Xiaoshu
authors.initials: X
authors.lastname: Hu
authors.affiliation: 4 Department of Radiology, Timmins District Hospital, Ontario, Canada.
authors.forename: Margaret H
authors.initials: MH
authors.lastname: Pui
authors.affiliation: 1 Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Quanfei
authors.initials: Q
authors.lastname: Meng
authors.affiliation: 1 Department of Radiology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, PR China.
authors.forename: Zhenhua
authors.initials: Z
authors.lastname: Gao
mesh_terms: D000293:Adolescent; D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D002648:Child; D002945:Cisplatin / Q000008:administration & dosage; D038524:Diffusion Magnetic Resonance Imaging / Q000379:methods*; D004317:Doxorubicin / Q000008:administration & dosage / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D007069:Ifosfamide / Q000008:administration & dosage; D023821:Limb Salvage; D008297:Male; D008727:Methotrexate / Q000008:administration & dosage; D020360:Neoadjuvant Therapy; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000473:pathology; D016896:Treatment Outcome
chemical_list: D004317:Doxorubicin; C027260:pirarubicin; D002945:Cisplatin; D007069:Ifosfamide; D008727:Methotrexate
keywords: Osteosarcoma; apparent diffusion coefficient (ADC); diffusion-weighted imaging (DWI); neoadjuvant chemotherapy