Alert: PYP Supply Interruption Update

Last week, ASNC alerted members that an interruption in the supply of the imaging agent 99mtechnetium-pyrophosphate (PYP) is expected to take place for several weeks beginning March 1, 2022. The shortage of PYP was first reported by Sun Radiopharma in early February due to supply chain concerns.
  • Sun Radiopharma expects to have PYP available by May 9, 2022.
  • The other manufacturer of PYP, Curium, also reported a shortage due to higher-than-expected demand. Curium expects to have PYP available in mid to late March. 

ASNC Consensus Clinical Recommendation

Over the past week, ASNC leaders have reached a consensus clinical recommendation that 99mtechnetium-hydroxymethylene diphosphonate (HMDP; also sometimes abbreviated HDP; also referred to as 99mtechnetium oxidronate) can be used as an alternative to PYP for the diagnosis of transthyretin cardiac amyloidosis.

HMDP is an FDA-approved radiopharmaceutical available in the United States. It has been used extensively in Europe for the diagnosis of transthyretin cardiac amyloidosis. Please note, HMDP/HDP is distinct from 99mtechnetium-methylene diphosphate (99mTc-MDP), and MDP is not recommended for the diagnosis of transthyretin cardiac amyloidosis. 

ASNC, in partnership with the European Association of Nuclear Medicine, published ASNC and EANM Cardiac Amyloidosis Practice Points: 99mtechnetium-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) and 99mtechnetium-hydroxymethylene diphosphonate (HMDP) Imaging for Transthyretin Cardiac Amyloidosis and recommends members review this document for guidance on using HMDP as an alternative to PYP. Gillmore et al reported that HMDP has high diagnostic accuracy, comparable to PYP, for the nonbiopsy diagnosis of cardiac transthyretin amyloidosis.[1]

The HCPCS level II code for HMDP is A9561 99mTechnetium oxidronate, diagnostic, per study dose, up to 20 millicuries and could be billed with the appropriate CPT code (78803- Radiopharmaceutical localization of tumor or distribution of Radiopharmaceutical agent(s); SPECT). CPT codes are copyrighted by the American Medical Association.

Members should reach out to their local nuclear pharmacy to determine if PYP is unavailable and if HMDP might be an available alternative.

Stay tuned to ASNC for further details as they become available. If you have questions, contact Georgia Lawrence at

1. Gillmore et al. Nonbiopsy Diagnosis of Cardiac Transthyretin Amyloidosis. Circulation, June 14, 2014;133(24):2404-12.