title: Indeterminate lesions on planar bone scintigraphy in lung cancer patients: SPECT, CT or SPECT-CT?
abstract: OBJECTIVE
  The objective of the present study was to compare the role of single photon emission computed tomography (SPECT), computed tomography (CT) and SPECT-CT of selected volume in lung cancer patients with indeterminate lesions on planar bone scintigraphy (BS).
  
  
  METHODS
  The data of 50 lung cancer patients (53 ± 10.3 years; range 30-75; male/female 38/12) with 65 indeterminate lesions on planar BS (January 2010 to November 2010) were retrospectively evaluated. All of them underwent SPECT-CT of a selected volume. SPECT, CT and SPECT-CT images were independently evaluated by two experienced readers (experience in musculoskeletal imaging, including CT: 5 and 7 years) in separate sessions. A scoring scale of 1 to 5 was used, in which 1 is definitely metastatic, 2 is probably metastatic, 3 is indeterminate, 4 is probably benign and 5 is definitely benign. Sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were calculated for each modality, taking a score ≤2 as metastatic. With receiver operating characteristic (ROC) curve analysis, areas under the curve (AUC) were calculated for each modality and compared. Clinical and imaging follow-up and/or histopathology were taken as reference standard.
  
  
  RESULTS
  For both readers SPECT was inferior to CT (P = 0.004, P = 0.022) and SPECT-CT (P = 0.003, P = 0.037). However, no significant difference was found between CT and SPECT-CT for reader 1 (P = 0.847) and reader 2 (P = 0.592). The findings were similar for lytic as well as sclerotic lesions. Moderate inter-observer agreement was seen for SPECT images (к = 0.426), while almost perfect agreement was seen for CT (к = 0.834) and SPECT-CT (к = 0.971).
  
  
  CONCLUSIONS
  CT alone and SPECT-CT are better than SPECT for accurate characterisation of indeterminate lesions on planar BS in lung cancer patients. CT alone is not inferior to SPECT-CT for this purpose and might be preferred because of shorter acquisition time and wider availability.
authors: Department of Nuclear Medicine, All India Institute of Medical Sciences, E-81, Ansari Nagar (East), AIIMS Campus, 110029, New Delhi, India.
authors: Punit
authors: P
authors: Sharma
authors: Rakesh
authors: R
authors: Kumar
authors: Harmandeep
authors: H
authors: Singh
authors: Chandrasekhar
authors: C
authors: Bal
authors: Pramod Kumar
authors: PK
authors: Julka
authors: Sanjay
authors: S
authors: Thulkar
authors: Arun
authors: A
authors: Malhotra
mesh_terms: D000328:Adult; D000368:Aged; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D002277:Carcinoma / Q000000981:diagnostic imaging* / Q000556:secondary*; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging*; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging / Q000379:methods*; D049268:Positron-Emission Tomography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*; D014057:Tomography, X-Ray Computed / Q000379:methods