Published online Nov 26, 2014. doi: 10.13105/wjma.v2.i4.212
Revised: August 11, 2014
Accepted: September 4, 2014
Published online: November 26, 2014
Processing time: 202 Days and 12.6 Hours
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 studies 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 ifosfamide-contained 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.
Core tip: Histopathological response to neoadjuvant chemotherapy is a significant prognostic factor and could guild the following treatment for patients with sarcoma. Novel molecular imaging such as 18-fluorodeoxy-D-glucose-positron emission tomography (PET) could offer non-invasive and accurate assessment of such response in sarcoma based on our relatively large-sample statistical analysis for this relatively rare tumor. More information that clinical physicians concerned with was generated, such as recommended subgroup of patients, potential candidates for quantitative criteria of response and possible causes of false positives of PET.