Heating is required during the preparation of all the following 99mTc labeled radiopharmaceuticals except for which one?

Bicisate, also known as ECD (ethyl cysteinate dimer), is a radiopharmaceutical that does not require heating during its preparation. The reason for this is that bicisate is produced through a more straightforward radiolabeling process that involves the direct combination of the compound with technetium-99m without the need for additional thermal activation.

In contrast, the other listed 99mTc labeled radiopharmaceuticals require heating as part of their preparation process. For example, filtered sulfur colloid is typically prepared through a process that involves heating to facilitate the proper formation of the colloidal particles and ensure adequate particle size for imaging. Similarly, sestamibi (known for myocardial perfusion imaging) requires heating to promote the proper binding of technetium-99m to the sestamibi molecule. Mertiatide (formerly known as MAG3) also involves heating steps to ensure the correct composition is achieved for renal imaging.

Understanding the specific preparation requirements for each radiopharmaceutical helps healthcare professionals in nuclear medicine ensure optimal radiopharmaceutical quality and performance in imaging applications.