title: Thallium-201 scintigraphy for the assessment of long-term prognosis in patients with osteosarcoma.
abstract: OBJECTIVE
  The aim of this study was to confirm the prognostic value of (201)Tl scintigraphy in the midcourse of preoperative chemotherapy in patients with osteosarcoma.
  
  
  METHODS
  The 28 patients with biopsy-proven osteosarcoma were enrolled retrospectively in this study. Planar scintigraphy was performed 15 min after injection of 111 MBq (201)Tl before preoperative chemotherapy and after third course (midcourse) of chemotherapy in all patients. The (201)Tl uptake ratio was calculated by dividing the count density of the lesion by that of the contralateral normal area. The percentage reduction of the (201)Tl uptake ratio calculated by 100 × [(pre-chemotherapy ratio - mid-chemotherapy ratio)/pre-chemotherapy ratio] was compared with the histopathological response and long-term survival rate.
  
  
  RESULTS
  Good histopathological response was observed in 16 patients. Mean follow-up period was 58.0 ± 41 months. Both overall and event-free survival rates of histopathologically good responders were significantly higher than that of poor responders (P = 0.018 and P = 0.0076). There was also significant correlation between pre-chemotherapeutic effect evaluated with (201)Tl scintigraphy and overall and event-free survival rate in all patients (P = 0.045 and P = 0.017, respectively), and in patients without metastasis at initial diagnosis (P = 0.043 and P = 0.031, respectively).
  
  
  CONCLUSIONS
  (201)Tl scintigraphy performed in the middle of neoadjuvant chemotherapy can predict overall survival and event-free survival in patients with osteosarcoma.
authors.affiliation: Department of Nuclear Medicine, Kanazawa University Hospital, 13-1 Takara-machi, Kanazawa, Ishikawa, 920-8641, Japan.
authors.forename: Anri
authors.initials: A
authors.lastname: Inaki
authors.forename: Junichi
authors.initials: J
authors.lastname: Taki
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wakabayashi
authors.forename: Hisashi
authors.initials: H
authors.lastname: Sumiya
authors.forename: Yoh
authors.initials: Y
authors.lastname: Zen
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Tsuchiya
authors.forename: Seigo
authors.initials: S
authors.lastname: Kinuya
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009362:Neoplasm Metastasis; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000473:pathology; D011379:Prognosis; D016016:Proportional Hazards Models; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D013794:Thallium Radioisotopes; D013997:Time Factors; D055815:Young Adult
chemical_list: D013794:Thallium Radioisotopes