SPECT/CT 90Y-Bremsstrahlung images for dosimetry during therapy.

Area of Science:

• Nuclear Medicine
• Radiopharmaceutical Therapy
• Medical Imaging

Background:

• Yttrium-90 (90Y) is a pure beta-emitter ideal for therapy but lacks gamma emission for imaging.
• Conventional imaging methods for 90Y conjugates have drawbacks.
• Advancements in SPECT/CT systems enable improved Bremsstrahlung imaging.

Purpose of the Study:

• To demonstrate the feasibility of obtaining high-quality 90Y-Bremsstrahlung SPECT/CT images.
• To evaluate the biodistribution of pure beta-emitter therapeutic agents during therapy.

Main Methods:

• Utilized a Siemens Symbia-T2 hybrid system for SPECT/CT imaging.
• Acquired images from a patient treated with 1.7 GBq of 90Y-DOTATATE.
• Employed specific SPECT energy windows (80, 120 keV) and low-dose CT for attenuation correction, with OSEM 3D-Fast reconstruction.

Main Results:

• Presented post-therapy 90Y-Bremsstrahlung SPECT/CT images of a patient undergoing receptor peptide radionuclide therapy.
• Demonstrated that 90Y-Bremsstrahlung images are suitable for tumor and normal organ dosimetry.
• Provided detailed biodistribution information comparable to 111In-diagnostic images.

Conclusions:

• Improved 90Y-Bremsstrahlung imaging facilitates patient recruitment and dosimetry for treated patients only.
• This technique may eliminate the need for different imaging isotopes.
• Clinical impact is significant, as dosimetry and toxicity data are crucial for radionuclide therapy, especially in high-risk patients.