AIM: To systematically evaluate the accuracy of 18-fluorodeoxy-D-glucose-positron emission tomography(18-FDG PET) to assess response to neoadjuvant chemotherapy in bone and soft tissue sarcomas.METHODS: Studies published in English language regarding the accuracy of F-18 FDG PET for the indication were retrieved from MEDLINE.The QUADAS tool was utilized for methodological quality appraisal.Relevant data were extracted,and quantitative data synthesis included pooled estimation and subgroup analysis.RESULTS: A total of fifteen studies involving 420 patients with pathologically confirmed sarcoma were collected.Methodological quality was relatively high.The pooled sensitivity and specificity of PET to predict histopathological response were 87%(95%CI: 81%-91%) and 83%(95%CI: 77%-87%),respectively.Ten stud-ies employed a lower standardized uptake value(SUV) after chemotherapies(mostly 2.5) and/or a higher SUV reduction rate(mostly around 50%) as PET criteria of good response.Subgroup analysis showed that PET exhibited a significantly better specificity in osteosarcoma(OS) and Ewing sarcoma(ES) than in soft-tissue sarcoma(STS)(91% vs 75%,P < 0.05),and a higher specificity in pediatric patients than in adults(90% vs 74%,P < 0.01).PET yielded a lower specificity in ifosfamidecontained chemotherapies than in the alternative regimen(70% vs 97%,P < 0.01).CONCLUSION: F-18 FDG PET is promising to predict neoadjuvant therapy response in sarcoma,especially in pediatric patients with OS or ES.Certain chemotherapeutic agents could potentially cause false positives of PET. AIM: To systematically evaluate the accuracy of 18-fluorodeoxy-D-glucose-positron emission tomography (18-FDG PET) to assess response to neoadjuvant chemotherapy in bone and soft tissue sarcomas. METHODS: Studies published in English language regarding the accuracy of F -18 FDG PET for the indication were retrieved from MEDLINE. The QUADAS tool was utilized for methodological quality appraisal. Revantvant data were extracted, and the quantitative data synthesis included pooled estimation and subgroup analysis. RESULTS: A total of fifteen studies involving 420 patients with pathologically confirmed sarcoma were collected. Methodological quality was relatively high. The pooled sensitivity and specificity of PET to predict histopathological response were 87% (95% CI: 81% -91%) and 83% (95% CI: 77% -87% , respectively. Ten stud-ies employed a lower standardized uptake value (SUV) after chemotherapies (mostly 2.5) and / or a higher SUV reduction rate (mostly around 50%) as PET criteria of good response. Subgroup analys is showed that PET showed a significantly better specificity in osteosarcoma (OS) and Ewing sarcoma (ES) than in soft-tissue sarcoma (STS) (91% vs 75%, P < adults (90% vs 74%, P <0.01). PETyielded a lower specificity in ifosfamidecontained chemotherapies than in the alternative regimen (70% vs 97%, P <0.01) .CONCLUSION: F-18 FDG PET is promising to predict neoadjuvant therapy response in sarcoma, especially in pediatric patients with OS or ES. Certain chemotherapeutic agents could potentially cause false positives of PET.