History
A 74-year-old male with a primary duodenal neuroendocrine tumor was referred for 68Ga DOTATATE PET/CT staging to evaluate suspected metastases. One hour and 17 minutes following a 4.3 mCi (158 MBq) intravenous (IV) injection of 68Ga DOTATATE, the patient underwent a 10-minute, single-bed, whole-body PET/CT acquisition on a Biograph Vision Quadra™ scanner.
Figure 1: Whole-body PET MIP images show extensive metastases throughout the body ranging from the vertex to the thighs, including multiple metastases in the thorax, liver, intestines, spine, pelvis, and bilateral femur. The PET MIP with a wider window setting (middle) helps differentiate between normal liver and 68Ga DOTATATE-avid liver metastases. The volume-rendered PET/CT image (right) also shows extensive metastases in the bones, liver, and intestines.
Findings
As seen in Figure 1, there are extensive metastases observed throughout the body with lesions in the bone, liver, and intestines. The physiological uptake of radionuclides in the normal liver parenchyma, spleen, kidney, ureter, bladder, bilateral adrenal glands, and pituitary gland appears within normal limits. As observed in Figures 2 and 3, the upper- and lower-most metastatic lesions—ranging from the skull base to the thighs—are sharply defined with equally high contrast-to-background levels due to the Biograph Vision Quadra’s 106 cm axial PET field of view (FoV), which enabled the single-bed, whole-body acquisition for this particular patient measuring 172 cm (5’7”) in height.
There are multiple metastases visualized from the primary neuroendocrine tumor, indicating high somatostatin-receptor density and intense avidity for 68Ga DOTATATE. These findings help inform the recommendation for the patient to proceed with 177Lu DOTATATE radionuclide therapy. By using DOTATATE-labeled ligands, this will help ensure that a similar level of therapeutic tracer intensity within lesions can be achieved for a high and sustained radiation dose to the metastatic lesions without undue normal tissue irradiation.
Discussion
Conclusion
This case demonstrates the role of 68Ga DOTATATE PET/CT imaging in the evaluation of somatostatin-receptor density within neuroendocrine tumor metastases. The 10-minute, single-bed, whole-body images acquired with Biograph Vision Quadra’s 106 cm axial PET FoV helped define metastatic burden and inform radionuclide therapy plans that involved the use of DOTATATE-labeled ligand.
Examination protocol
Scanner: Biograph Vision Quadra
The outcomes achieved by the Siemens Healthineers customers described herein were achieved in the customer’s unique setting. Since there is no
“typical” hospital and many variables exist (eg, hospital size, case mix, level of IT adoption) there can be no guarantee that others will achieve
the same results.
