title: Usefulness of triple-phase thallium-201 SPECT in non-small-cell lung cancer (NSCLC): association with proliferative activity.
abstract: OBJECTIVE
  The conventional delayed scan in dual phase of thallium-201 ((201)Tl) single-photon emission computed tomography (SPECT) is useful for estimating the viability of non-small-cell lung cancer (NSCLC). However, the influence of tumor blood flow cannot be ignored by the scan at 4 h after the tracer injection. For the purpose of improving the diagnostic capability and for clarifying the association between (201)Tl uptake and proliferative activity, we investigated the usefulness of super-delayed scan obtained at 24 h in triple-phase (201)Tl SPECT.
  
  
  METHODS
  A total of 122 patients with lung nodule, 106 of NSCLC and 16 of benign nodule, were given (201)Tl SPECT before the tumor resection. Early image (15 min), delayed image (4 h), and super-delayed image (24 h) were obtained after intravenous injection of (201)Tl chloride (111 MBq). On the each SPECT image, regions of interest (ROIs) were placed over the tumor contour (T) and contra-lateral normal lung tissue (N) area on one transverse view clearly defined lesions, and T/N ratio on the early image (ER), the delayed image (DR), and the super-delayed image (sDR), and retention indexes (RI and sRI) were calculated. All patients underwent subsequent surgical excision, and the specimens were immunostained for Ki-67 and CD34. The proliferative capability was measured as a percentage of positive nuclear area for Ki-67 (MIB-1 index). The angiogenesis was measured density of positive micro-vessels for CD34 (micro-vessel density, MVD). Correlation analysis was performed to evaluate the relationship between the MIB-1 index, MVD, and SPECT parameters.
  
  
  RESULTS
  The diagnostic accuracy of sDR in the differential of NSCLC was higher than that of DR (83.6% vs. 91.8%). Both DR and sDR were positively correlated with MIB-1 index. The correlation coefficient was higher in sDR (0.53 vs. 0.69). The MIB-1 index of the increasing pattern (RI < sRI) group was significantly higher (P < 0.001) than that of the decreasing pattern (RI > sRI) group.
  
  
  CONCLUSIONS
  The super-delayed scan in the triple-phase (201)Tl SPECT is more useful than conventional delayed scan for both the diagnostic capability and assessing proliferation of NSCLC.
authors.affiliation: Department of Radiology, Miyazaki Medical College, 5200 Kihara, Kiyotake-cho, Miyazaki 889-1692, Japan. fujita@fujimoto.or.jp
authors.forename: Seigo
authors.initials: S
authors.lastname: Fujita
authors.forename: Shigeki
authors.initials: S
authors.lastname: Nagamachi
authors.forename: Hideyuki
authors.initials: H
authors.lastname: Wakamatsu
authors.forename: Ryuichi
authors.initials: R
authors.lastname: Nishii
authors.forename: Shigemi
authors.initials: S
authors.lastname: Futami
authors.forename: Shozo
authors.initials: S
authors.lastname: Tamura
authors.forename: Yasunori
authors.initials: Y
authors.lastname: Matsuzaki
authors.forename: Toshio
authors.initials: T
authors.lastname: Onizuka
authors.forename: Kinta
authors.initials: K
authors.lastname: Hatakeyama
authors.forename: Yujiro
authors.initials: Y
authors.lastname: Asada
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D002289:Carcinoma, Non-Small-Cell Lung / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D007275:Injections, Intravenous; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D019275:Radiopharmaceuticals / Q000008:administration & dosage; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013793:Thallium / Q000008:administration & dosage; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D019275:Radiopharmaceuticals; C027549:thallium chloride; D013793:Thallium