18F-FDG PET SUVmax correlates with osteosarcoma histologic response to neoadjuvant chemotherapy: preclinical evaluation in an orthotopic rat model.
Assessment of osteosarcoma response to neoadjuvant chemotherapy is performed by histopathologic analysis after surgical resection of the primary tumor. The purpose of this study was to evaluate whether (18)F-FDG PET could be a noninvasive surrogate to histopathologic analysis and allow for earlier response evaluation to neoadjuvant chemotherapy in osteosarcoma.


METHODS
Metabolic response to neoadjuvant chemotherapy was assessed in immunocompetent rats with a preestablished orthotopic osteosarcoma using (18)F-FDG PET before and after receiving 2 doses of ifosfamide. Comparison was then made by assessing histologic responses on euthanized animals.


RESULTS
Maximum standardized uptake value (SUVmax) measured by (18)F-FDG PET after 2 doses of chemotherapy was correlated to histologic classification (P < 0.01). An SUVmax less than 15 corresponded to good responders, whereas an SUVmax greater than 15 but less than 20 and an SUVmax greater than 20 corresponded to partial responders or nonresponders, respectively. A 40% decrease in SUVmax between the first and second (18)F-FDG PET scans distinguished between partial and good response to chemotherapy.


CONCLUSIONS
Determination of SUVmax using semiquantitative (18)F-FDG PET predicts response to neoadjuvant chemotherapy earlier than does histologic analysis.
Dutour
Aurélie
A
Inserm; Centre Léon Bérard, Lyon, France. dutoura@lyon.fnclcc.fr
Decouvelaere
Anne-Valérie
AV
Monteil
Jacques
J
Duclos
Marie-Eve
ME
Roualdes
Olivier
O
Rousseau
Raphaël
R
Marec-Bérard
Perrine
P
D000818:Animals; D000970:Antineoplastic Agents / Q000008:administration & dosage*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D004195:Disease Models, Animal; D004353:Drug Evaluation, Preclinical; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics*; D006801:Humans; D008657:Metabolic Clearance Rate; D020360:Neoadjuvant Therapy; D012516:Osteosarcoma / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000473:pathology*; D049268:Positron-Emission Tomography / Q000379:methods*; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D013223:Statistics as Topic; D016896:Treatment Outcome
D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18