Incidental Cardiac Uptake on 99mTc-HMDP Bone Scintigraphy in Oncology Patients: Two Cases of Transthyretin Amyloid Cardiomyopathy with Literature Review

TL;DR

This paper reports two cases where bone scans in cancer patients revealed heart issues linked to a rare heart disease, highlighting the importance of this incidental finding for early diagnosis.

Contribution

The novelty lies in demonstrating how bone scintigraphy can incidentally detect transthyretin amyloid cardiomyopathy in oncology patients.

Findings

Two elderly breast cancer patients showed myocardial uptake on 99mTc-HMDP scans, leading to diagnosis of ATTRwt-CM.

Literature review summarizes cardiac uptake frequency and clinical relevance in cancer patients.

Early detection via bone scintigraphy may improve outcomes for ATTRwt-CM.

Abstract

Background: Bone scintigraphy using technetium-99m hydroxymethylene diphosphonate (99mTc-HMDP) is extensively employed to detect bone metastases. However, incidental myocardial uptake may indicate wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM), a frequently overlooked diagnosis with important clinical implications. Case Presentation: Two elderly female patients with a history of breast cancer were subjected to 99mTc-HMDP bone scintigraphy as part of a routine evaluation for possible bone metastases. Both cases demonstrated incidental myocardial uptake (Perugini Grade 2 and Grade 3, respectively), raising suspicion for ATTRwt-CM, which was subsequently confirmed by endomyocardial biopsy. Review of the Literature: We reviewed published studies reporting cardiac uptake on bone scintigraphy, summarizing the frequency, patient demographics, and tracer types, and emphasizing the clinical relevance of this finding in cancer patients. Conclusions: In oncology patients, bone scintigraphy performed during routine metastatic screening may facilitate early detection of ATTRwt-CM, enabling timely diagnosis and treatment initiation, potentially improving clinical outcomes.

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