title: Changes observed in radionuclide bone scans during and after teriparatide treatment for osteoporosis.
abstract: OBJECTIVE
  Visual changes on radionuclide bone scans have been reported with teriparatide treatment. To assess this, serial studies were evaluated and quantified in ten postmenopausal women with osteoporosis treated with teriparatide (20 μg/day subcutaneous) who had (99m)Tc-methylene diphosphonate (MDP) bone scans (baseline, 3 and 18 months, then after 6 months off therapy).
  
  
  METHODS
  Women were injected with 600 MBq (99m)Tc-MDP, and diagnostic bone scan images were assessed at 3.5 h. Additional whole-body scans (10 min, 1, 2, 3 and 4 h) were analysed for (99m)Tc-MDP skeletal plasma clearance (K(bone)). Regional K(bone) differences were obtained for the whole skeleton and six regions (calvarium, mandible, spine, pelvis, upper and lower extremities). Bone turnover markers (BTM) were also measured.
  
  
  RESULTS
  Most subjects showed visual changes on 3- and 18-month bone scan images that disappeared after 6 months off therapy. Enhanced uptake was seen predominantly in the calvarium and lower extremities. Whole skeleton K(bone) displayed a median increase of 22% (3 months, p = 0.004) and 34% (18 months, p = 0.002) decreasing to 0.7% (6 months off therapy). Calvarium K(bone) changes were three times larger than other sites. After 6 months off therapy, all K(bone) and BTM values returned towards baseline.
  
  
  CONCLUSIONS
  The increased (99m)Tc-MDP skeletal uptake with teriparatide indicated increased bone formation which was supported by BTM increases. After 6 months off therapy, metabolic activity diminished towards baseline. The modulation of (99m)Tc-MDP skeletal uptake during treatment was the result of teriparatide's metabolic activity. These findings may aid the radiological evaluation of similar teriparatide patients having radionuclide bone scans.
authors: Department of Nuclear Medicine, Borough Wing; Guy's Hospital, King's College London School of Medicine, St. Thomas Street, London SE1 9RT, UK. amelia.moore@kcl.ac.uk
authors: Amelia E B
authors: AE
authors: Moore
authors: Glen M
authors: GM
authors: Blake
authors: Kathleen A
authors: KA
authors: Taylor
authors: Valerie A
authors: VA
authors: Ruff
authors: Asad E
authors: AE
authors: Rana
authors: Xiaohai
authors: X
authors: Wan
authors: Ignac
authors: I
authors: Fogelman
mesh_terms: D000368:Aged; D015519:Bone Density; D016723:Bone Remodeling; D001842:Bone and Bones / Q000000981:diagnostic imaging* / Q000473:pathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D010024:Osteoporosis / Q000175:diagnosis / Q000188:drug therapy*; D015663:Osteoporosis, Postmenopausal / Q000175:diagnosis / Q000188:drug therapy; D011877:Radionuclide Imaging; D013669:Technetium Tc 99m Medronate / Q000627:therapeutic use; D019379:Teriparatide / Q000494:pharmacology*; D013997:Time Factors; D051598:Whole Body Imaging / Q000379:methods
chemical_list: D019379:Teriparatide; D013669:Technetium Tc 99m Medronate