Capabilities of Combined Positron Emission and Computed Tomography in Neuroendocrine Tumor Diagnostics: First Experience of Russian Synthesis Module 68Ga-DOTA-TATE
Year: 2016
Type: article
Abstract: The aim of the investigation was to estimate the sensitivity of combined positron emission and computed tomography (PET/CT) in the diagnostics, extension and treatment efficiency of neuroendocrine tumors (NET) using 68 Ga-DOTA-TATE as an imaging agent. Materials and Methods.PET/CT with 68 Ga-DOTA-TATE was performed in 86 patients with pulmonary and gastrointestinal NET (55 patients underwent it preoperatively, 31 patients -postoperatively).All patients before PET/СТ were administered a diagnostic dose of radiopharmaceutical (RP) at the rate of 1.5 MBq per a kilogram of body mass but not less than 100 MBq.The developed RP synthesis module (Gerat13-68 Ga) enabled to prepare a ready for intravenous administration 68 Ga-DOTA-TATE within 15 min.Moreover, RP was defined to have a stably high radiochemical yield (over 50% without decay correction) and the appropriate quality.The patients were scanned 50-60 min after RP injection, the procedure being carried out according to a whole body protocol using PET/CT Discovery 690 (General Electric, USA).The data processing included the image analysis of computed and positron emission tomograms, as well as combined images.The main feature of sst-positive tissue tumor was pathological focal 68 Ga-DOTA-TATE hyperfixation even if there were no evident structural changes of the organ according to CT findings.In cases when CT showed a tumor but the tumor didn't accumulated RP, its nature was considered to be malignant and the tumor was estimated as sst-negative.Results.In patients examined before treatment, the sensitivity of PET/CT with 68 Ga-DOTA-TATE to diagnose a primary tumor was 90.9% (50/55).In 3 patients PET showed a sst-negative tumor, in 2 patients a primary mass was not detected after tomography either.In addition, an initially determined stage of the disease was confirmed by PET/CT in 36 of 47 cases (76.6%).The rest patients were found to have second metastases in different organs and systems.PET/CT findings in 13 of 31 patients examined after the treatment didn't coincide with those obtained by other techniques.In 6 patients the presence of pathological PR accumulation indicated no positive effect of the therapy, 3 patients were found to have secondary changes, 3 patients were detected to have a significant increase of liver metastases (only in CT), and 1 female patient after surgery appeared to have the disease recurrence in the stump of the left main bronchus.
Language: English
Subfield: Oncology
Field: Medicine
Domain: Health Sciences
Open Access status: diamond
OpenAlex ID: W2563379596