EDUCATION AND CPD | Case Study
THE EFFICACY OF NUCLEAR MEDICINE SCINTIGRAPHY IN THE DETECTION OF CARDIAC AMYLOIDOSIS: A CASE-BASED APPROACH
Marianna Elias, University of South Australia
A
& Judge 2020). The Nuclear Medicine BSTRACT: Cardiac bone scintigraphy was acquired to Amyloidosis (CA) is char- evaluate for cardiac amyloidosis and acterised as insoluble consolidate previous findings. amyloid plaque depositions within the myocardium and is INTRODUCTION: An 86-year-old often associated with several clinical male inpatient presented into the manifestations (Wong & Judge 2020) department with increasing shortness The two common subtypes involving of breath and known atrial fibrillation the myocardium are Immunoglobin with a referral to evaluate for possible light chain (AL) and Transthyretin CA. A CMR image acquisition to eval(ATTR) amyloid plaques (Wong & uate for infiltrative heart disease and Judge 2020). ATTR and AL cardiac monitor left ventricular hypertrophy amyloidosis can be distinguished preceded the nuclear medicine examthrough using nuclear medicine scin- ination. tigraphy utilising the Technetium 99m Hydroxy-methylene-diphosphonate Amyloidosis refers to the deposition (99m Tc-HDP) bone-seeking radio- of extracellular insoluble and atyppharmaceutical. This tracer, like other ical extracellular fibrils that transpire 99m Tc phosphonate derivatives, from the accumulation of misfolded, accumulates in ATTR amyloid deposi- usually soluble proteins sourced by tions, with the cause for this phenom- the liver (Sun et al. 2018). CA is the enon remaining unknown (Treglia et deposition and aggregation of fibril al. 2018; Khor et al. 2020). We present plaques into the myocardium (Wong a case of an 86-year-old male patient & Judge 2020). Systemic amyloidosis who presented to the department in the form of Immunoglobulin light following a cardiac Magnetic Reso- chains (AL) and Transthyretin (ATTR) nance (CMR) Imaging investigation are the most common plaque types to evaluate for newly diagnosed atrial that aggregate in the myocardium fibrillation and increasing shortness and manifest from genetic predispoof breath. These clinical manifesta- sitions or are classified as tions being typical of that of cardiac amyloidosis (Wong
50
GAMMA GAZETTE WINTER EDITION 2021 | ANZSNM.ORG.AU
senile (Wong & Judge 2020). CA can be a clinical indicator of congestive heart failure with preserved ejection fraction and rapidly progressive, restrictive cardiomyopathy (Kuria, Gitau & Makhdomi 2019). Diastolic and systolic dysfunctions may also ensue (Sun et al. 2018). Nuclear medicine bone scintigraphy is utilised to assess and differentiate between AL and ATTR CA and monitor disease progression (Bokhari et al. 2013). Differentiation between these subtypes, is pertinent for an improved patient prognosis, in that ATTR and AL CA each require separate treatment pathways and clinical management (Bokhari et al. 2013; Khor et al. 2020). NUCLEAR MEDICINE PROCEDURE & FINDINGS PATIENT PREPARATION: The departmental nuclear medicine bone scintigraphy protocol was utilised. Initially the procedure and a bone questionnaire were discussed with the patient, and at which time it was established that the patient had nil bone pain, with no oncological history. Verbal and written consent was also obtained.
