title: High-grade soft-tissue sarcomas: tumor response assessment--pilot study to assess the correlation between radiologic and pathologic response by using RECIST and Choi criteria.
abstract: OBJECTIVE
  To compare radiologic response as defined according to both Response Evaluation Criteria in Solid Tumors (RECIST) and the new Choi criteria recently proposed for gastrointestinal stromal tumors with pathologic response in high-grade soft-tissue sarcomas (STSs) treated with preoperative chemotherapy and radiation therapy.
  
  
  METHODS
  The institutional ethical committee approved the trial in which patients were enrolled. Signed informed consent was obtained. Thirty-seven patients (21 men, 16 women; mean age, 44.2 years) enrolled in a collaborative randomized trial on preoperative chemotherapy and radiation therapy in localized high-risk STS at a single institution were selected for this retrospective analysis. Tumor response to preoperative treatment was assessed by using both RECIST and Choi criteria at computed tomography (CT) and was adapted to be used at magnetic resonance (MR) imaging. Pathologic response was assessed as either good or very good. Sensitivity, specificity, and predictive value of RECIST and Choi criteria were calculated with pathologic response as the reference standard and were reported with 95% confidence intervals.
  
  
  RESULTS
  For 28 patients without synovial sarcomas, sensitivity of RECIST versus adapted Choi criteria was 32.0% versus 88.0% for good response and 41.2% versus 82.4% for very good response, respectively; specificity for pathologic response was 100% versus 100% for not a good response and 90.9% versus 27.3% for not a very good response, respectively. In synovial sarcoma, the nontreatment-related neoplastic cystic component of the tumor was a major obstacle for both RECIST and Choi criteria.
  
  
  CONCLUSIONS
  In STS treated with chemotherapy and radiation therapy, tumor size may be insufficient to render actual tumor response. Tumor attenuation at CT or tumor contrast material enhancement at MR imaging may complement tumor size, thus making Choi criteria more predictive of pathologic response.
authors.affiliation: Department of Cancer Medicine, Fondazione IRCCS Istituto Nazionale Tumori, Via Venezian 1, 20133 Milan, Italy. silvia.stacchiotti@istitutotumori.mi.it
authors.forename: Silvia
authors.initials: S
authors.lastname: Stacchiotti
authors.forename: Paola
authors.initials: P
authors.lastname: Collini
authors.forename: Antonella
authors.initials: A
authors.lastname: Messina
authors.forename: Carlo
authors.initials: C
authors.lastname: Morosi
authors.forename: Marta
authors.initials: M
authors.lastname: Barisella
authors.forename: Rossella
authors.initials: R
authors.lastname: Bertulli
authors.forename: Claudio
authors.initials: C
authors.lastname: Piovesan
authors.forename: Palma
authors.initials: P
authors.lastname: Dileo
authors.forename: Valter
authors.initials: V
authors.lastname: Torri
authors.forename: Alessandro
authors.initials: A
authors.lastname: Gronchi
authors.forename: Paolo Giovanni
authors.initials: PG
authors.lastname: Casali
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001706:Biopsy; D005260:Female; D046152:Gastrointestinal Stromal Tumors / Q000175:diagnosis* / Q000628:therapy*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008875:Middle Aged; D017063:Outcome Assessment, Health Care / Q000379:methods; D010865:Pilot Projects; D011379:Prognosis; D015203:Reproducibility of Results; D012509:Sarcoma / Q000175:diagnosis* / Q000628:therapy*; D012680:Sensitivity and Specificity; D013223:Statistics as Topic; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome; D055815:Young Adult