title: 99mTc-sestamibi scintigraphy to monitor the long-term efficacy of enzyme replacement therapy on bone marrow infiltration in patients with Gaucher disease.
abstract: Assessing the skeletal response to enzyme replacement therapy (ERT) in Gaucher disease (GD) is problematic. We investigated the reliability of (99m)Tc-sestamibi scintigraphy in monitoring changes in bone marrow involvement induced by ERT.
  
  
  METHODS
  In 52 GD patients, the efficacy of ERT on bone marrow disease was monitored using at least 2 sequential (99m)Tc-sestamibi scans; 17 patients were receiving ERT at enrollment, and 35 were ERT-naïve. We elaborated a dose-response model by statistical analysis based on linear mixed models.
  
  
  RESULTS
  Patients whose marrow disease improved had received a significantly higher ERT dose per month than patients who did not improve. Significantly more patients reached near-disappearance of marrow disease if their disease burden at enrollment had been lower and the duration of clinical signs shorter. The response of the marrow scintigraphic score was more pronounced in ERT-naïve patients. No relevant effect of ERT on marrow disease was observed until platelet count and splenomegaly had improved.
  
  
  CONCLUSIONS
  Although based on localized evaluation, changes in the (99m)Tc-sestamibi score closely correlated with the main determinants of ERT, with a definite dose-response relationship. The threshold at which ERT induced any improvement in bone marrow disease was 35-36 U/kg/mo; in ERT-naïve patients, the scintigraphic score declined by 1 unit after ERT at 28 U/kg/mo.
authors.affiliation: Regional Center of Nuclear Medicine, University of Pisa, Pisa, Italy.
authors.forename: Paola A
authors.initials: PA
authors.lastname: Erba
authors.forename: Fabrizio
authors.initials: F
authors.lastname: Minichilli
authors.forename: Fiorina
authors.initials: F
authors.lastname: Giona
authors.forename: Silvia
authors.initials: S
authors.lastname: Linari
authors.forename: James
authors.initials: J
authors.lastname: Dambrosia
authors.forename: Anna
authors.initials: A
authors.lastname: Pierini
authors.forename: Mirella
authors.initials: M
authors.lastname: Filocamo
authors.forename: Maja
authors.initials: M
authors.lastname: Di Rocco
authors.forename: Ferdinando
authors.initials: F
authors.lastname: Buffoni
authors.forename: Roscoe O
authors.initials: RO
authors.lastname: Brady
authors.forename: Giuliano
authors.initials: G
authors.lastname: Mariani
mesh_terms: D000328:Adult; D001855:Bone Marrow Diseases / Q000150:complications* / Q000000981:diagnostic imaging*; D056947:Enzyme Replacement Therapy; D005260:Female; D005776:Gaucher Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D008297:Male; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D017256:Technetium Tc 99m Sestamibi; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D017256:Technetium Tc 99m Sestamibi
keywords: 99mTc-sestamibi; Gaucher disease; bone marrow disease; enzyme replacement therapy; scintigraphic score