Quantitative terbium-161 SPECT/CT imaging: demonstrating the feasibility of image-based dosimetry and highlighting pitfalls.

ABSTRACT:

Background

Terbium-161 (¹⁶¹Tb) is a promising β⁻-emitter for theragnostics. However, its complex photon emission pattern-including intense X-rays and low-yield, high-energy γ-emissions-may complicate image-based quantification. This study aimed to assess the feasibility of accurate SPECT/CT-based ¹⁶¹Tb dosimetry through a series of phantom measurements using a GE Discovery NM/CT 670 Pro system. Three collimators were evaluated: extended low-energy general-purpose (ELEGP), low-energy high-resolution (LEHR), and medium-energy general-purpose (MEGP), using two separate energy windows: around the 75 keV γ-peak (± 10%), and around the 49 keV γ-peak and nearby X-rays (40.7-62.9 keV). A clinical OSEM reconstruction algorithm was employed.

Results

On average, t

SUBMITTER: Westerbergh F 

PROVIDER: S-EPMC12518732 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature