title: [Value of thallium-201 scintigraphy in assessment of neoadjuvant chemotherapy for osteosarcoma].
abstract: OBJECTIVE
  To investigate the significance of Tl-201 scintigraphy for assessment of neoadjuvant chemotherapy for osteosarcoma.
  
  
  METHODS
  Thirty-four cases with osteosarcoma were enrolled into this study. The Tl-201 scintigraphy features including uptake ratio(UR) and size ratio(SR) were obtained in both early and delay imaging stages before and after chemotherapy. The responses of chemotherapy were classified into three grades according to the percentage of tumor necrosis in the specimens: necrosis < 50% as grade 1, necrosis of 50% approximately 90% as grade 2, diffuse necrosis > 90% as grade 3. The alteration ratio (AR) and SR were calculated according to tumor necrosis ratio (TNR).
  
  
  RESULTS
  Of the 6 patients with grade 1 response, the mean alteration ratios were 3.19% +/- 8.40% and -26.29% +/- 63.61% in early and delay imaging stages, respectively. Among the 18 patients with grade 2 response, the mean alteration ratios were 40.07% +/- 11.95% and 39.30% +/- 9.87%, respectively. Of the 10 patients with grade 3 response, the mean alteration ratios were 78.32% +/- 8.33% and 63.26% +/- 6.06% in early and delay imaging stages, respectively. The results of liner regression analysis of TNR of the surgical specimens showed a significantly positive correlation (r = 0.71) between AR and TNR. The lesion size was reduced in 18 cases, but unchanged in 8 and increased in 8. The liner regression analysis results showed a negative correlation between SR and TNR.
  
  
  CONCLUSIONS
  The alteration ratio changes significantly after neoadjuvant chemotherapy and has a significantly positive correlation with tumor necrosis ratio. Thallium-201 scintigraphy is helpful in the evaluation of neoadjuvant chemotherapy for osteosarcoma.
authors.affiliation: Department of Nuclear Medicine, Sir Run Run Shaw Hospital, Zhejiang University, Hangzhou 310016, China.
authors.forename: Zhong-ke
authors.initials: ZK
authors.lastname: Huang
authors.forename: Cen
authors.initials: C
authors.lastname: Lou
authors.forename: Xiang-qian
authors.initials: XQ
authors.lastname: Fang
mesh_terms: D000293:Adolescent; D000328:Adult; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D002648:Child; D005260:Female; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D006801:Humans; D008297:Male; D020360:Neoadjuvant Therapy; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000188:drug therapy / Q000473:pathology; D011877:Radionuclide Imaging; D013794:Thallium Radioisotopes; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D013794:Thallium Radioisotopes