title: Evaluation of Bone Metastasis from Hepatocellular Carcinoma Using (18)F-FDG PET/CT and (99m)Tc-HDP Bone Scintigraphy: Characteristics of Soft Tissue Formation.
abstract: OBJECTIVE
  Bone metastasis from hepatocellular carcinoma (HCC) can present with soft tissue formation, resulting in oncologic emergency. Contrast-enhanced FDG PET/CT and bone scintigraphy were compared to evaluate characteristics of bone metastases with or without soft tissue formation from HCC.
  
  
  METHODS
  Of 4,151 patients with HCC, 263 patients had bone metastases. Eighty-five patients with bone metastasis from HCC underwent contrast-enhanced FDG PET/CT. Fifty-four of the enrolled subjects had recent (99m)Tc-HDP bone scintigraphy available for comparison. Metastatic bone lesions were identified with visual inspection on FDG PET/CT, and maximum standardized uptake value (SUVmax) was used for the quantitative analysis. Confirmation of bone metastasis was based on histopathology, combined imaging modalities, or serial follow-up studies.
  
  
  RESULTS
  Forty-seven patients (55%) presented with soft tissue formation, while the remaining 38 patients presented without soft tissue formation. Frequent sites of bone metastases from HCC were the spine (39%), pelvis (19%), and rib cage (14%). The soft-tissue-formation group had more frequent bone pain (77 vs. 37%, p < 0.0001), higher SUVmax (6.02 vs. 3.52, p < 0.007), and higher incidence of photon defect in bone scintigraphy (75 vs. 0%) compared to the non-soft-tissue-formation group. FDG PET/CT had higher detection rate for bone metastasis than bone scintigraphy both in lesion-based analysis (98 vs. 53%, p = 0.0015) and in patient-based analysis (100 vs. 80%, p < 0 .001).
  
  
  CONCLUSIONS
  Bone metastasis from HCC showed a high incidence of soft tissue formation requiring emergency treatment. Although the characteristic findings for soft tissue formation such as photon defect in bone scintigraphy are helpful in detection, overall detectability of bone metastasis is higher in FDG PET/CT. Contrast-enhanced PET/CT will be useful in finding and delineating soft-tissue-forming bone metastasis from HCC.
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Hyo Jung
authors.initials: HJ
authors.lastname: Seo
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Yun Jung
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Hyun Jeong
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Yong Hyu
authors.initials: YH
authors.lastname: Jeong
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Arthur
authors.initials: A
authors.lastname: Cho
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Jae Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Mijin
authors.initials: M
authors.lastname: Yun
authors.affiliation: Division of Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Choi
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Jong Doo
authors.initials: JD
authors.lastname: Lee
authors.affiliation: Division of Nuclear Medicine, Department of Radiology, Yonsei University College of Medicine, Seongsanno250, Seodaemun-gu, Seoul, 120-752 Korea.
authors.forename: Won Jun
authors.initials: WJ
authors.lastname: Kang
keywords: Bone metastasis; Fluorodeoxyglucose; Hepatocellular carcinoma; Positron emission tomography; Soft tissue formation