title: Imaging assessment of the responses of osteosarcoma patients to preoperative chemotherapy: angiography compared with thallium-201 scintigraphy.
abstract: BACKGROUND
  Assessment of the responses of osteosarcoma patients to preoperative chemotherapy is of clinical importance. The purpose of this study was to estimate the accuracy of angiography and thallium-201 scintigraphy, compared with histology, in assessing the responses of patients with osteosarcoma to preoperative chemotherapy.
  
  
  METHODS
  Nineteen patients with osteosarcoma who were diagnosed between 1992 and 1997 were studied. The findings of angiography and thallium-201 scintigraphy before and after preoperative chemotherapy were compared with the percentage of necrosis of tumor cells and the response grade as determined histologically. Quantitative analysis of the isotopic uptake by thallium-201 scintigraphy before and after chemotherapy, defined as the alteration ratio, was correlated with the percentage of tumor necrosis.
  
  
  RESULTS
  Angiography yielded a sensitivity of 88%, a specificity of 73%, and a predictive accuracy of positive test of 70%, whereas thallium-201 scintigraphy achieved 88%, 100%, and 100%, respectively. Both angiographic and scintigraphic assessment showed a significant correlation with response grade as determined histologically (P < 0.05 and P < 0.0003, respectively). The alteration ratio of thallium-201 scintigraphy showed a strong, highly significant correlation with the percentage of tumor necrosis (P < 0.0001).
  
  
  CONCLUSIONS
  A change in the tumor uptake of thallium-201 scintigraphy after preoperative chemotherapy can predict the tumor necrosis in osteosarcoma precisely. Thallium scintigraphy is a noninvasive technique and seems to be more useful than angiography in assessing the response of osteosarcoma to preoperative chemotherapy.
authors.affiliation: Department of Orthopaedic Surgery, Okayama University Medical School, Okayama, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Kunisada
authors.forename: T
authors.initials: T
authors.lastname: Ozaki
authors.forename: A
authors.initials: A
authors.lastname: Kawai
authors.forename: S
authors.initials: S
authors.lastname: Sugihara
authors.forename: K
authors.initials: K
authors.lastname: Taguchi
authors.forename: H
authors.initials: H
authors.lastname: Inoue
mesh_terms: D000293:Adolescent; D000328:Adult; D015901:Angiography, Digital Subtraction; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D002648:Child; D002675:Child, Preschool; D005260:Female; D005266:Femoral Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy; D006652:Histological Techniques; D006801:Humans; D008297:Male; D012516:Osteosarcoma / Q000000981:diagnostic imaging* / Q000188:drug therapy; D011300:Preoperative Care; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes; D013977:Tibia
chemical_list: D000970:Antineoplastic Agents; D019275:Radiopharmaceuticals; D013794:Thallium Radioisotopes