title: Utility and limitations of 3,3-diphosphono-1,2-propanodicarboxylic acid scintigraphy in systemic amyloidosis.
abstract: OBJECTIVE
  Technetium-99m-labelled 3,3-diphosphono-1,2-propanodicarboxylic acid ((99m)Tc-DPD) is a sensitive method for imaging cardiac transthyretin (ATTR) amyloid. We report utility and limitations of (99m)Tc-DPD scintigraphy in 321 patients with suspected cardiac amyloidosis.
  
  
  RESULTS
  The cohort included wild-type ATTR (ATTRwt) amyloidosis in 94 (29%), ATTR-Val122Ile amyloidosis in 38 (12%), hereditary ATTR (ATTRmt) amyloidosis in 46 (14%), primary light-chain (AL) amyloidosis in 44 (14%), secondary (AA) amyloidosis in three (1%), other hereditary amyloidosis types in nine (3%), undetermined types in two (0.5%), and 85 (26.5%) patients in whom systemic amyloidosis was ultimately excluded. All 158 patients with ATTR amyloidosis with clinical cardiac involvement had cardiac (99m)Tc-DPD uptake, with median Grade 2 intensity. Thirteen further ATTR amyloidosis patients without clinical evidence of cardiac involvement also demonstrated (99m)Tc-DPD cardiac uptake. Eighteen of 35 (51%) AL patients with cardiac involvement had (99m)Tc-DPD cardiac uptake (median Grade 1 intensity). SPECT imaging indicates that the apparent reciprocal reduction in bone uptake is due to masking of bone uptake by extensive soft-tissue uptake in ATTR amyloidosis, especially ATTRwt, and ATTR-Val122Ile types.
  
  
  CONCLUSIONS
  (99m)Tc-DPD scintigraphy is a highly sensitive technique for imaging cardiac ATTR amyloidosis and is an important investigation in the diagnostic pathway of patients with cardiac amyloidosis. It is not specific for ATTR in isolation but must be interpreted in a broad clinical context to avoid dangerous diagnostic errors. Diffuse skeletal muscle uptake identifies muscle as a hitherto unrecognized site that merits investigation as a target organ in ATTR amyloidosis.
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK.
authors.forename: David F
authors.initials: DF
authors.lastname: Hutt
authors.affiliation: Nuclear Medicine Department, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Anne-Marie
authors.initials: AM
authors.lastname: Quigley
authors.affiliation: Nuclear Medicine Department, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Joanne
authors.initials: J
authors.lastname: Page
authors.affiliation: Nuclear Medicine Department, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Hall
authors.affiliation: Nuclear Medicine Department, Royal Free London NHS Foundation Trust, London, UK.
authors.forename: Maria
authors.initials: M
authors.lastname: Burniston
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Dorothea
authors.initials: D
authors.lastname: Gopaul
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Thirusha
authors.initials: T
authors.lastname: Lane
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Carol J
authors.initials: CJ
authors.lastname: Whelan
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Helen J
authors.initials: HJ
authors.lastname: Lachmann
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Julian D
authors.initials: JD
authors.lastname: Gillmore
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK.
authors.forename: Philip N
authors.initials: PN
authors.lastname: Hawkins
authors.affiliation: National Amyloidosis Centre, UCL Medical School (Royal Free Campus), Rowland Hill Street, London NW3 2PF, UK a.wechalekar@ucl.ac.uk.
authors.forename: Ashutosh D
authors.initials: AD
authors.lastname: Wechalekar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000686:Amyloidosis / Q000000981:diagnostic imaging* / Q000235:genetics*; D001706:Biopsy; D004164:Diphosphonates / Q000493:pharmacokinetics; D005260:Female; D006331:Heart Diseases / Q000000981:diagnostic imaging* / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000493:pharmacokinetics; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012680:Sensitivity and Specificity
chemical_list: D004164:Diphosphonates; D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C033905:technetium Tc 99m 1,1-diphosphonopropane-2,3-dicarboxylic acid
keywords: 99mTc DPD scintigraphy; ATTR; Cardiac amyloid; Soft tissue; Transthyretin