Using Q.Metrix to Evaluate Treatment Response to PRRT for Neuroendocrine Tumors of Gastroenteric or Pancreatic Origin

• Areas of Interest:

  • PRRT

  • Theragnostics

Objective: This study aimed to evaluate the treatment response to PRRT for neuroendocrine tumors of gastroenteric or pancreatic origin using Q.Metrix.

Background: We present a case of a 57-year-old male with metastatic neuroendocrine tumor. The patient was treated with monthly injections of lanreotide for 6 months, prior to consideration for ¹⁷⁷Lu-DOTATATE radionuclide therapy due to significant disease progression.

Methods: Q.Metrix application on the GE Xeleris software system was used to assess the treatment response of cycles 1 and 2 of ¹⁷⁷Lu-DOTATATE, using whole-body scintigraphy and SPECT/CT. After premedication and primed with amino acid infusion for renoprotection, the patient was infused with 202.7 mCi for cycle 1 and 205.4 mCi for cycle 2 of ¹⁷⁷Lu-DOTATATE, using standard protocols. A whole-body scan and SPECT/CT over the abdomen was acquired at 30 minutes, 6 hours, 24 hours, and 72 hours post-¹⁷⁷Lu-DOTATATE infusion with a reference in position for dosimetry calculations. Using the Q.Metrix application on the GE Xeleris workstation, volumes of interests (VOIs) were drawn around the liver, stomach, and tumors for the data acquired for cycle one at the 24-hour time point. The regions were then transferred to the data acquired for cycle two using rigid registration of the low-dose CTs.

Results: The primary tumor in the stomach showed a reduction in activity of 81.3%, while activity in the liver metastases showed a 54% reduction of activity. The patient has also clinically improved with no further gastrointestinal bleeding or abdominal pain.

Conclusion: The Q.Metrix application is a valuable tool in assisting with quantitative assessment of treatment response of patients with neuroendocrine tumors treated with ¹⁷⁷Lu-DOTATATE.

Publikationsverlauf

Artikel online veröffentlicht:
10. Mai 2022