Gallium-68-somatostatin receptor PET/CT parameters as potential prognosticators for clinical time to progression after peptide receptor radionuclide therapy: a cohort study

• Published in: European journal of hybrid imaging Vol. 5; no. 1; p. 22
• Main Authors: Ebbers, Sander C., Heimgartner, Muriël, Barentsz, Maarten W., van Leeuwaarde, Rachel S., van Treijen, Mark J. C., Lam, Marnix M. E. G., Braat, Arthur J. A. T.
• Format: Journal Article
• Language: English
• Published: Cham Springer International Publishing 09-12-2021; Springer Nature B.V; SpringerOpen
• Subjects: [68Ga]Ga-DOTA-TOC PET/CT; Cohort analysis; Computed tomography; Gallium; Gallium isotopes; Imaging; Medical prognosis; Medicine; Medicine & Public Health; Neuroendocrine tumors; Nuclear Medicine; Original; Original Article; Parameter identification; Patients; Peptides; PET-based response; Positron emission; Positron emission tomography; Progression-free survival; PRRT; Radiation therapy; Radioisotopes; Radiology; Receptors; Somatostatin; Somatostatin receptors; Statistical models; Time-to-new treatment; Tomography; Tumors; PRRT; [; Ga]Ga-DOTA-TOC PET/CT; PET-based response; Progression-free survival; Time-to-new treatment; [68Ga]Ga-DOTA-TOC PET/CT
• ISSN: 2510-3636; 2510-3636
• DOI: 10.1186/s41824-021-00116-z

Background
Early [
68
Ga]Ga-DOTA-TOC PET/CT imaging after peptide receptor radionuclide therapy (PRRT) in neuroendocrine neoplasm patients is often used as a prognosticator for survival, but lacks validity. This study investigates the prognostic value of changes in PET parameters after PRRT.
Methods
Baseline and follow-up [
68
Ga]Ga-DOTA-TOC PET/CT scans of all patients treated with PRRT were delineated automatically. Total lesion somatostatin receptor expression (TL-SSTR) and somatostatin receptor expressing tumor volume (SSTR-TV) were used as covariates in Cox proportional hazard models to predict time-to-new treatment.
Results
In twenty patients, median time-to-new treatment was 19.3 months (range [3.8; 36.2]). Absolute and percentual changes in both PET parameters were not associated with time-to-new treatment. A significant relation between independent baseline and follow-up SSTR-TV and follow-up TL-SSTR, and time-to-new treatment was identified.
Conclusions
Automatically derived [
68
Ga]Ga-DOTA-TOC PET/CT parameters are easy to acquire and may be of prognostic value after completing PRRT. Acquiring SSTR-TV or TL-SSTR parameters at baseline and during follow-up can be of value in identifying a patient’s prognosis.