**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Maria Koutelou, MD, PhD, MSc, Nuclear Medicine Department Onassis Cardiac Surgery Center, Athens, Greece, 356 Sygrou Avenue, 17674 Kallithea, email: marinucl@hotmail.com

**Main Body of the Abstract**
Introduction
In this study, we explore the diagnostic potential of 99mTc-labeled pyrophosphate (PYP) and 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) in cardiac amyloidosis, specifically distinguishing between light-chain (AL) and transthyretin (TTR) types.
Case presentation
A case of a 76-year-old woman with symptoms such as shortness of breath, peripheral congestion, and hand numbness revealed atypical echocardiographic and laboratory findings, indicating cardiac involvement. Despite concentric left ventricular hypertrophy, right ventricular hypertrophy, and severe diastolic dysfunction, the patient exhibited normal systolic function but impaired longitudinal function, indicative of cardiac amyloidosis.
A subsequent 99mTc-DPD study displayed an unexpected pattern of significantly increased soft tissue uptake in visceral, lung, and muscle regions, sparing traditionally affected organs. This unique uptake pattern was distinct from the typical distribution observed in both AL and TTR amyloidosis cases. The absence of cardiac uptake in single photon emission computed tomography (SPECT) images further emphasized this peculiarity.
Confirmation of AL amyloidosis was obtained through soft tissue biopsies and positive urine tests for Bence-Jones protein. The patient, at cardiac stage IIIb, responded well to a medication regimen including daratumumab, bortezomib, melphalan, and dexamethasone.
Conclusion
This case prompts consideration of 99mTc-DPD soft tissue uptake in unconventional areas as a potential indicator for AL-type amyloidosis, contrasting with the limited applicability of PYP due to its minimal soft tissue uptake. The absence of radiopharmaceutical mislabeling or technical issues reinforces the reliability of these findings, underscoring the need for further investigation into the diagnostic utility of soft tissue uptake patterns in cardiac amyloidosis



**Author Listing - Lead/ Submitting Author (we will be communicating with this individual): Name, Institution, City and State where the work was done. Co-authors will be added in a separate section.**
Maria Koutelou, MD, PhD, MSc, Nuclear Medicine Department Onassis Cardiac Surgery Center, Athens, Greece, 356 Sygrou Avenue, 17674 Kallithea, email: [marinucl@hotmail.com](mailto:marinucl@hotmail.com)

**Main Body of the Abstract**
**Introduction**
In this study, we explore the diagnostic potential of 99mTc-labeled pyrophosphate (PYP) and 3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) in cardiac amyloidosis, specifically distinguishing between light-chain (AL) and transthyretin (TTR) types.
**Case presentation**
A case of a 76-year-old woman with symptoms such as shortness of breath, peripheral congestion, and hand numbness revealed atypical echocardiographic and laboratory findings, indicating cardiac involvement. Despite concentric left ventricular hypertrophy, right ventricular hypertrophy, and severe diastolic dysfunction, the patient exhibited normal systolic function but impaired longitudinal function, indicative of cardiac amyloidosis.
A subsequent 99mTc-DPD study displayed an unexpected pattern of significantly increased soft tissue uptake in visceral, lung, and muscle regions, sparing traditionally affected organs. This unique uptake pattern was distinct from the typical distribution observed in both AL and TTR amyloidosis cases. The absence of cardiac uptake in single photon emission computed tomography (SPECT) images further emphasized this peculiarity.
Confirmation of AL amyloidosis was obtained through soft tissue biopsies and positive urine tests for Bence-Jones protein. The patient, at cardiac stage IIIb, responded well to a medication regimen including daratumumab, bortezomib, melphalan, and dexamethasone.
**Conclusion**
This case prompts consideration of 99mTc-DPD soft tissue uptake in unconventional areas as a potential indicator for AL-type amyloidosis, contrasting with the limited applicability of PYP due to its minimal soft tissue uptake. The absence of radiopharmaceutical mislabeling or technical issues reinforces the reliability of these findings, underscoring the need for further investigation into the diagnostic utility of soft tissue uptake patterns in cardiac amyloidosis



Unusually seen pattern of 99mTc-DPD soft tissue uptake in a patient with AL amyloidosis. Is it an amyloid type indicator in specific cases? PB99 (#62)

We invite you to attend the XIX International Symposium on Amyloidosis to be held in Rochester, MN.

This symposium is organized as a hybrid meeting (with the focus on in-person) held from Sunday, May 26 through Thursday, May 30, 2024.

Together with the ISA Board and members of Mayo Clinic, a very attractive scientific hybrid program is being planned. The program will cover a variety of types of systemic amyloidosis: ATTR (hereditary and wild-type), AL (light-chain), AA and less frequent forms. There will be key lectures, specific symposia including those company sponsored, oral presentations and poster sessions of accepted abstracts.

COURSE DESCRIPTION
This program will provide a comprehensive review of state-of-the-art education in systemic amyloidosis: basic science, pathophysiology, diagnosis, current and emerging treatments. Scientific presentations will include competitive oral and poster abstracts. The rapid evolution of scientific discovery and expanding treatment options has created tremendous interest in the field and this meeting will fill and important gap in educating scientists and clinicians.