title: Pure ground glass nodular adenocarcinomas: Are preoperative positron emission tomography/computed tomography and brain magnetic resonance imaging useful or necessary?
abstract: OBJECTIVE
  The utility of (18)F-Fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) scanning and brain magnetic resonance imaging (MRI) as a staging workup for lung adenocarcinoma manifesting as pure ground glass opacity (GGO) is unknown. The purpose of this study was to determine the utility of these 2 tests for preoperative staging of pure GGO nodular lung adenocarcinoma.
  
  
  METHODS
  The study included 164 patients (male:female, 73:91; mean age, 62 years) with pure GGO nodular lung adenocarcinoma who underwent PET/CT (in 136 patients) and/or brain MRI (in 109 patients) before surgery. Pathologic N staging and dedicated standard imaging or follow-up imaging findings for M staging were used as reference standards. The median follow-up time was 47.9 months.
  
  
  RESULTS
  On PET/CT scan, abnormal FDG uptake of lymph nodes was found in 2 of 136 patients (1.5%); both were negative on final pathology. Abnormal FDG uptake of the liver was detected in 1 patient, which was also confirmed to be negative by dedicated abdominal CT. The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of PET/CT in detecting metastases were not applicable, 98% (95% confidence interval [CI], 94%-100%), 0% (95% CI, 0%-71%), 100% (95% CI, 97%-100%), and 98% (95% CI, 94%-100%), respectively. No brain metastasis was found in preoperative brain MRI of 109 patients. Of 109 patients, 1 (0.9%) developed brain metastasis 30 months after surgical resection.
  
  
  CONCLUSIONS
  PET/CT and brain MRI is not necessary in the staging of pure GGO nodular lung adenocarcinoma.
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hyoun
authors.initials: H
authors.lastname: Cho
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea. Electronic address: hoyunlee96@gmail.com.
authors.forename: Ho Yun
authors.initials: HY
authors.lastname: Lee
authors.affiliation: Department of Thoracic Surgery and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Jhingook
authors.initials: J
authors.lastname: Kim
authors.affiliation: Department of Thoracic Surgery and Cardiovascular Surgery, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Hong Kwan
authors.initials: HK
authors.lastname: Kim
authors.affiliation: Department of Nuclear Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.affiliation: Division of Pulmonary and Critical Care Medicine, Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Sang-Won
authors.initials: SW
authors.lastname: Um
authors.affiliation: Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Kyung Soo
authors.initials: KS
authors.lastname: Lee
mesh_terms: D000230:Adenocarcinoma / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000556:secondary / Q000601:surgery; D000077192:Adenocarcinoma of Lung; D000368:Aged; D001932:Brain Neoplasms / Q000175:diagnosis* / Q000556:secondary; D005189:False Positive Reactions; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008113:Liver Neoplasms / Q000175:diagnosis* / Q000556:secondary; D008175:Lung Neoplasms / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery; D008207:Lymphatic Metastasis; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D064847:Multimodal Imaging; D009367:Neoplasm Staging; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D011300:Preoperative Care / Q000379:methods*; D019275:Radiopharmaceuticals; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D019564:Unnecessary Procedures
chemical_list: D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18
keywords: brain MRI; ground-glass opacity; imaging; integrated positron emission tomography/computed tomography; lung adenocarcinoma; staging