RT Journal Article SR Electronic T1 18F-FLT PET/CT as a Prognostic Imaging Biomarker of Disease-Specific Survival in Patients with Primary Soft-Tissue Sarcoma JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 708 OP 712 DO 10.2967/jnumed.121.262502 VO 63 IS 5 A1 Joseph G. Crompton A1 Wesley R. Armstrong A1 Mark A. Eckardt A1 Ameen Seyedroudbari A1 William D. Tap A1 Sarah M. Dry A1 Evan R. Abt A1 Jeremie Calais A1 Ken Herrmann A1 Johannes Czernin A1 Fritz C. Eilber A1 Matthias R. Benz YR 2022 UL http://jnm.snmjournals.org/content/63/5/708.abstract AB The purpose of this study was to evaluate 18F-FLT PET/CT as an early prognostic imaging biomarker of long-term overall survival and disease-specific survival (DSS) in soft-tissue sarcoma (STS) patients treated with neoadjuvant therapy (NAT) and surgical resection. Methods: This was a 10-y follow-up of a previous single-center, single-arm prospective clinical trial. Patients underwent 18F-FLT PET/CT before treatment (PET1) and after NAT (PET2). Posttreatment pathology specimens were assessed for tumor necrosis or fibrosis and for Ki-67 and thymidine kinase 1 expression. Maximally selected cutoffs for PET and histopathologic factors were applied. Survival was calculated from the date of subject consent to the date of death or last follow-up. Results: The study population consisted of 26 patients who underwent PET1; 16 of the 26 with primary STS underwent PET2. Thirteen deaths occurred during a median follow-up of 104 mo. In the overall cohort, overall survival was longer in patients with a low than a high PET1 tumor SUVmax (dichotomized by an SUVmax of ≥8.5 vs. <8.5: not yet reached vs. 49.7 mo; P = 0.0064). DSS showed a trend toward significance (P = 0.096). In a subanalysis of primary STS, DSS was significantly longer in patients with a low PET1 tumor SUVmax (dichotomized by an SUVmax of ≥8 vs. <8; P = 0.034). There were no significant 18F-FLT PET response thresholds corresponding to DSS or overall survival after NAT at PET2. Conclusion: 18F-FLT PET may serve as a prognostic baseline imaging biomarker for DSS in patients with primary STS.