gallium-ga-68-dotatate and Neoplasm-Metastasis

Topics: Antineoplastic Agents; Carcinoma, Neuroendocrine; Humans; Neoplasm Metastasis; Neoplasm Staging; Organometallic Compounds; Peptides, Cyclic; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Sensitivity and Specificity; Somatostatin

18F-FDG PET/CT is widely used to evaluate indeterminate pulmonary nodules (IPNs). False positive results occur, especially from active granulomatous nodules. A PET-based imaging agent with superior specificity to 18F-FDG for IPNs, is badly needed, especially in areas of endemic granulomatous nodules. Somatostatin receptors (SSTR) are expressed in many malignant cells including small cell and non-small cell lung cancers (NSCLCs). 68Ga-DOTATATE, a positron emitter labeled somatostatin analog, combined with PET/CT imaging, may improve the diagnosis of IPNs over 18F-FDG by reducing false positives. Our study purpose was to test this hypothesis in our region with high endemic granulomatous IPNs.. We prospectively performed 68Ga-DOTATATE PET/CT and 18F-FDG PET/CT scans in the same 30 patients with newly diagnosed, treatment-naïve lung cancer (N = 14) or IPNs (N = 15) and one metastatic nodule. 68Ga-DOTATATE SUVmax levels at or above 1.5 were considered likely malignant. We analyzed the scan results, correlating with ultimate diagnosis via biopsy or 2-year chest CT follow-up. We also correlated 68Ga-DOTATATE uptake with immunohistochemical (IHC) staining for SSTR subtype 2A (SSTR2A) in pathological specimens.. We analyzed 31 lesions in 30 individuals, with 14 (45%) being non-neuroendocrine lung cancers and 1 (3%) being metastatic disease. McNemar's result comparing the two radiopharmaceuticals (p = 0.65) indicates that their accuracy of diagnosis in this indication are equivalent. 68Ga-DOTATATE was more specific (94% compared to 81%) and less sensitive 73% compared to 93%) than 18F-FDG. 68Ga-DOTATATE uptake correlated with SSTR2A expression in tumor stroma determined by immunohistochemical (IHC) staining in 5 of 9 (55%) NSCLCs.. 68Ga-DOTATATE and 18F-FDG PET/CT had equivalent accuracy in the diagnosis of non-neuroendocrine lung cancer and 68Ga-DOTATATE was more specific than 18F-FDG for the diagnosis of IPNs. IHC staining for SSTR2A receptor expression correlated with tumor stroma but not tumor cells.

Topics: Adult; Aged; Biopsy; Carcinoma, Non-Small-Cell Lung; Diagnosis, Differential; Female; Humans; Lung Neoplasms; Male; Middle Aged; Multimodal Imaging; Multiple Pulmonary Nodules; Neoplasm Metastasis; Organometallic Compounds; Positron Emission Tomography Computed Tomography

Quantitative imaging and dosimetry are crucial for individualized treatment during peptide receptor radionuclide therapy (PRRT). (177)Lu-DOTATATE and (68)Ga-DOTATOC/(68)Ga-DOTATATE are used, respectively, for PRRT and PET examinations targeting somatostatin receptors (SSTRs) in patients affected by neuroendocrine tumors. The aim of the study was to quantitatively and qualitatively compare the performance of (68)Ga-DOTATOC and (68)Ga-DOTATATE in the context of subsequent PRRT with (177)Lu-DOTATATE under standardized conditions in the same patient as well as to investigate the sufficiency of standardized uptake value (SUV) for estimation of SSTR expression.. Ten patients with metastatic neuroendocrine tumors underwent one 45-min dynamic and 3 whole-body PET/CT examinations at 1, 2, and 3 h after injection with both tracers. The number of detected lesions, SUVs in lesions and normal tissue, total functional tumor volume, and SSTR volume (functional tumor volume multiplied by mean SUV) were investigated for each time point. Net uptake rate (Ki) was calculated according to the Patlak method for 3 tumors per patient.. There were no significant differences in lesion count, lesion SUV, Ki, functional tumor volume, or SSTR volume between (68)Ga-DOTATOC and (68)Ga-DOTATATE at any time point. The detection rate was similar, although with differences for single lesions in occasional patients. For healthy organs, marginally higher uptake of (68)Ga-DOTATATE was observed in kidneys, bone marrow, and liver at 1 h. (68)Ga-DOTATOC uptake was higher in mediastinal blood pool at the 1-h time point (P = 0.018). The tumor-to-liver ratio was marginally higher for (68)Ga-DOTATOC at the 3-h time point (P = 0.037). Blood clearance was fast and similar for both tracers. SUV did not correlate with Ki linearly and achieved saturation for a Ki of greater than 0.2 mL/cm(3)/min, corresponding to an SUV of more than 25.. (68)Ga-DOTATOC and (68)Ga-DOTATATE are suited equally well for staging and patient selection for PRRT with (177)Lu-DOTATATE. However, the slight difference in the healthy organ distribution and excretion may render (68)Ga-DOTATATE preferable. SUV did not correlate linearly with Ki and thus may not reflect the SSTR density accurately at its higher values, whereas Ki might be the outcome measure of choice for quantification of SSTR density and assessment of treatment outcome.

Topics: Adult; Aged; Female; Humans; Liver; Male; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Neuroendocrine Tumors; Octreotide; Organometallic Compounds; Positron-Emission Tomography; Quality Control; Radiation Dosage; Radiometry; Reproducibility of Results; Sensitivity and Specificity; Time Factors; Tomography, X-Ray Computed; Treatment Outcome; Whole Body Imaging

We hypothesized that (68)Ga-DOTATATE uptake of neuroendocrine tumors is sensitive to therapy with a nonradioactive somatostatin analog.. (68)Ga-DOTATATE PET/CT was used to examine 105 patients, 35 of whom had been pretreated with long-acting octreotide. The maximum standardized uptake value (SUV(max)) of target tissues, as well as metastases, was compared between the groups of patients with (group 1) and without (group 2) octreotide treatment.. The SUV(max) of the spleen and liver was significantly lower in group 1 than in group 2 (both P < 0.001). There were no significant group differences in SUV(max) for primary tumors (28.6 ± 6.8 vs. 32.9 ± 31.5) or metastases in the liver (27.2 ± 14.8 vs. 25.7 ± 10.7), lymph nodes (41.4 ± 19.5 vs. 25.0 ± 6.3), or skeleton (39.5 ± 22.0 vs. 15.4 ± 7.8). In 9 patients available for intraindividual comparison, tumor uptake was unaffected by treatment with somatostatin analogs (21.7 vs. 20.6; P = 0.93).. Treatment with a long-acting somatostatin analog did not significantly reduce (68)Ga-DOTATATE binding in neuroendocrine tumors but tended to improve the tumor-to-background ratio.

Topics: Adult; Aged; Aged, 80 and over; Biological Transport; Female; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Octreotide; Organometallic Compounds; Positron-Emission Tomography; Tomography, X-Ray Computed; Young Adult

Radiolabeled somatostatin analogs represent valuable tools for both in vivo diagnosis and therapy of neuroendocrine tumors (NETs) because of the frequent tumoral overexpression of somatostatin receptors (sst). The 2 compounds most often used in functional imaging with PET are (68)Ga-DOTATATE and (68)Ga-DOTATOC. Both ligands share a quite similar sst binding profile. However, the in vitro affinity of (68)Ga-DOTATATE in binding the sst subtype 2 (sst2) is approximately 10-fold higher than that of (68)Ga-DOTATOC. This difference may affect their efficiency in the detection of NET lesions because it is the sst2 that is predominantly overexpressed in NET. We thus compared the diagnostic value of PET/CT with both radiolabeled somatostatin analogs ((68)Ga-DOTATATE and (68)Ga-DOTATOC) in the same NET patients.. Forty patients with metastatic NETs underwent (68)Ga-DOTATOC and (68)Ga-DOTATATE PET/CT as part of the work-up before prospective peptide receptor radionuclide therapy. The performance of both imaging methods was analyzed and compared for the detection of individual lesions per patient and for 8 defined body regions. A region was regarded positive if at least 1 lesion was detected in that region. In addition, radiopeptide uptake in terms of the maximal standardized uptake value (SUVmax) was compared for concordant lesions and renal parenchyma.. Seventy-eight regions were found positive with (68)Ga-DOTATATE versus 79 regions with (68)Ga-DOTATOC (not significant). Overall, however, significantly fewer lesions were detected with (68)Ga-DOTATATE than with (68)Ga-DOTATOC (254 vs. 262, P < 0.05). Mean (68)Ga-DOTATATE SUVmax across all lesions was significantly lower than (68)Ga-DOTATOC (16.0 ± 10.8 vs. 20.4 ± 14.7, P < 0.01). Mean SUVmax for renal parenchyma was not significantly different between (68)Ga-DOTATATE and (68)Ga-DOTATOC (12.7 ± 3.0 vs. 13.2 ± 3.3).. (68)Ga-DOTATOC and (68)Ga-DOTATATE possess a comparable diagnostic accuracy for the detection of NET lesions, with (68)Ga-DOTATOC having a potential advantage. The approximately 10-fold higher affinity for the sst2 of (68)Ga-DOTATATE does not prove to be clinically relevant. Quite unexpectedly, SUVmax of (68)Ga-DOTATOC scans tended to be higher than their (68)Ga-DOTATATE counterparts.

Topics: Adult; Aged; Aged, 80 and over; Biological Transport; Female; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Octreotide; Organometallic Compounds; Positron-Emission Tomography; Tomography, X-Ray Computed

We present a case of a 55-year-old man with a history of poorly differentiated metastatic thyroid cancer, which is rare and shows aggressive behavior. The patient had radioactive iodine-negative multiple metastasis on 18F-FDG PET/CT, therefore 68Ga-DOTATATE and 68Ga-PSMA PET/CT were performed whether an opportunity exist for DOTATATE or PSMA-directed radionuclide therapy. Different patterns of tumoral uptakes were detected on 18F-FDG, 68Ga-DOTATATE, and 68Ga-PSMA PET/CT, as a demonstration of tumor heterogeneity.

Topics: Edetic Acid; Fluorodeoxyglucose F18; Gallium Isotopes; Gallium Radioisotopes; Humans; Male; Middle Aged; Neoplasm Metastasis; Oligopeptides; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Thyroid Neoplasms

We investigated the role of Ga-68 DOTATATE PET/CT in comparison to F-18 FDG PET/CT in patients with low and intermediate versus high-grade neuroendocrine tumors (NETs).. We identified 81 patients who underwent Ga-68 DOTATATE PET/CT at our institution between May 2017 and December 2018 and met inclusion criteria of biopsy-proven NET with known Ki-67 index, histologic grade, or differentiation. Patients were divided into two groups. Control group included Ki-67 ≤20%, grade 1 or 2, or well-differentiated tumors. Experimental group included Ki-67 >20%, grade 3, or poorly-differentiated tumors.. Mean age was 57 years, with 36 males and 45 females. Most common primary sites were small bowel, pancreas, and lung. Most common distant metastatic sites were liver and bone. In the control group (n = 67), median Ki-67 was 4% (range 1-30%). 55/67 (82.1%) DOTATATE and 6/11 (54.5%) FDG scans were positive (P = 0.04). Positive scans showed >10 lesions in 25/55 (45.5%) DOTATATE and 1/6 (16.7%) FDG scans (P = 0.18). 40/55 (72.7%) positive DOTATATE and 3/6 (50%) FDG scans showed distant disease (P = 0.25). In the experimental group (n = 14), median Ki-67 was 68% (range 25-95%). All 14 DOTATATE and all nine FDG scans were positive. Positive scans showed >10 lesions in 4/14 (28.6%) DOTATATE and 5/9 (55.6%) FDG scans (P = 0.20). 10/14 (71.4%) positive DOTATATE and 7/9 (77.8%) FDG scans showed distant disease (P = 0.74).. All patients with high grade, poorly-differentiated NETs had positive DOTATATE PET/CTs. In these patients, DOTATATE PET/CT did not significantly differ from FDG PET/CT in identifying >10 lesions or distant disease.

Topics: Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Neoplasm Grading; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron Emission Tomography Computed Tomography

Prostate large cell neuroendocrine tumor is a rare disease. In this case, metastatic areas showing FDG uptake, somatostatin receptor positivity, and PSMA expression are shown in F-FDG PET/CT, Ga-DOTATATE PET/CT, and Ga-PSMA PET/CT in a 70-year-old man with the diagnosis of prostate large cell neuroendocrine carcinoma.

Topics: Aged; Edetic Acid; Fluorodeoxyglucose F18; Gallium Isotopes; Gallium Radioisotopes; Humans; Male; Neoplasm Metastasis; Neuroendocrine Tumors; Oligopeptides; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Prostatic Neoplasms; Radiopharmaceuticals

A 71-year-old man with history of prostate cancer is evaluated for rising prostate-specific antigen. The patient also has a history of rectal well-differentiated neuroendocrine tumor. On F-fluciclovine PET/CT, 2 retroperitoneal lymph nodes exhibited intense fluciclovine avidity, whereas one enlarged perirectal lymph node only showed background uptake. On further Ga-DOTATATE PET/CT, the perirectal lymph node revealed intense DOTATATE avidity, whereas the 2 retroperitoneal lymph nodes only with similar to background DOTATATE avidity. Biopsy of the perirectal lymph node confirmed metastasis from neuroendocrine tumor. The distinct imaging characteristics of metastases from different primary malignancies correlated with their underlying different pathology.

Topics: Adenocarcinoma; Aged; Carboxylic Acids; Carcinoid Tumor; Cyclobutanes; Humans; Intestinal Neoplasms; Male; Neoplasm Metastasis; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Prostatic Neoplasms; Radiopharmaceuticals; Rectal Neoplasms

Ga-DOTATATE is a radiolabeled somatostatin analog used for the detection and characterization of somatostatin receptor (SSR)-overexpressing tumors, particularly well-differentiated neuroendocrine tumors. We present a case of a 65-year-old man with well-differentiated pancreatic neuroendocrine tumor post-Whipple surgery and a new liver lesion on CT. Ga-DOTATATE PET/CT was performed for SSR characterization and restaging, which demonstrated the lesion to be intensely SSR positive and interpreted as a neuroendocrine metastasis. However, subsequent pathology proved the lesion to be a hepatocellular carcinoma. This case adds hepatocellular carcinoma as a potentially DOTATATE-avid malignancy to be considered in the differential diagnoses of SSR-positive liver lesions.

Topics: Aged; Carcinoma, Hepatocellular; Humans; Liver Neoplasms; Male; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Pancreatic Neoplasms; Positron Emission Tomography Computed Tomography; Receptors, Somatostatin

Germline succinate dehydrogenase (SDHx) mutation carriers, especially SDHB, are at increased risk for malignancy and require life-long surveillance. Current guidelines recommend periodic whole-body MRI imaging. We assessed the incremental value of 68Ga-DOTA-octreotate (GaTate) positron emission tomography (PET)/CT compared with conventional imaging in such patients.. SDHx mutation carriers who had GaTate PET/CT were retrospectively reviewed. Detection of lesions were compared with MRI or CT on a per-patient and per-lesion basis. Proof of lesions were based on histopathology or clinical/imaging follow-up.. Twenty consecutive patients (median age, 46 years; 10 males) were reviewed. Fourteen patients had SDHB, four, SDHD, one SDHC, and one SDHA mutation. Fifteen had prior surgery and/or radiotherapy. Indications for PET/CT were as follows: 7 patients for surveillance for previously treated disease, 9 residual disease, 2 asymptomatic mutation carriers, and 2 for elevated catecholamines. Median time between modalities was 1.5 months.GaTate PET/CT had higher sensitivity and specificity than conventional imaging. On a per-patient basis: PET/CT sensitivity 100%, specificity 100%; MRI/CT 85% and 50%. Per-lesion basis: PET/CT sensitivity 100%, specificity 75%; MRI/CT 80% and 25%. PET/CT correctly identified additional small nodal and osseous lesions. MRI/CT had more false-positive findings. Change of management resulted in 40% (8/20 patients): 3 received localized treatment instead of observation, 1 changed to observation given extra disease detected, 4 with metastases had radionuclide therapy.. GaTate PET/CT provided incremental diagnostic information with consequent management impact in SDHx-pheochromocytoma and paraganglioma. Incorporating this modality as part of a surveillance program seems prudent. Further research is needed to define the optimal surveillance strategy including use of MRI.

Topics: Adolescent; Adrenal Gland Neoplasms; Adult; Aged; Catecholamines; False Positive Reactions; Female; Follow-Up Studies; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Multimodal Imaging; Mutation; Neoplasm Metastasis; Organometallic Compounds; Paraganglioma; Pheochromocytoma; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Retrospective Studies; Sensitivity and Specificity; Treatment Outcome; Young Adult

Both F-FDG and Ga-DOTATATE PET/CT are used in the evaluation of pheochromocytomas. We reported F-FDG and Ga-DOTATATE PET/CT findings in a 60-year-old man who had recurrent metastatic pheochromocytoma coexisting with lung adenocarcinoma. The metastatic pheochromocytoma showed increased activity on both F-FDG and Ga-DOTATATE PET/CT, whereas the lung adenocarcinoma lesion showed no obvious DOTATATE activity.

Topics: Adenocarcinoma of Lung; Adrenal Gland Neoplasms; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Neoplasm Metastasis; Neoplasms, Second Primary; Organometallic Compounds; Pheochromocytoma; Positron Emission Tomography Computed Tomography

Ninety-two patients (44 men and 48 women, mean age of 59.5-year-old) with pathologically confirmed WD-NET (grades 1 or 2) were enrolled in a prospective expanded access protocol. Selected data was analyzed retrospectively for this project. Maximum standardized uptake value (SUV. Univariate analyses revealed significant difference of PFS for WHO tumor grade and ΣSRETV (P < 0.05), while there were no significant differences in age, sex, SUV

Topics: Adult; Aged; Aged, 80 and over; Disease Progression; Disease-Free Survival; Female; Humans; Image Processing, Computer-Assisted; Kaplan-Meier Estimate; Liver Neoplasms; Male; Middle Aged; Multivariate Analysis; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Prognosis; Progression-Free Survival; Proportional Hazards Models; Prospective Studies; Receptors, Somatostatin; Retrospective Studies

Topics: Aluminum; Chelating Agents; Heterocyclic Compounds, 1-Ring; Humans; Male; Middle Aged; Neoplasm Metastasis; Neuroendocrine Tumors; Octreotide; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Rectal Neoplasms

Respiratory motion during PET/CT acquisition generates artifacts in the form of breath-related blurring, which influences the lesion detectability and diagnostic accuracy. The goal of this study was to verify whether breath-hold [68Ga]DOTA-TOC PET/CT (bhPET) allows detection of additional foci compared to free-breathing PET/CT (fbPET), and to assess the impact of breath-holding on standard uptake values (SUV) and isocontoured volume (Vic40) in patients with neuroendocrine tumors (NET).. Patients with NET (N.=39) were included in this study. BhPET and fbPET characteristics of 96 lesions were compared, and correlated with standard contrast-enhanced (ce) CT and MRI for lesion verification. Quantitative parameters SUV (max and mean) and Vic40 were assessed for both methods and evaluated by linear regression and Spearman's correlation. The impact of lesion size, localization and time interval between investigations was also analyzed.. bhPET identified one additional metastasis not seen at fbPET but visible at ceMRI. Another additional bhPET focus did not have a morphological correlate. At bhPET, the SUVmax and SUVmean proved significantly higher and the Vic40 significantly lower than at fbPET. Lesion size, localization and time intervals did not impact significantly on SUV or Vic40.. Currently, routine use of breath-hold [68Ga]DOTA-TOC PET/CT cannot be recommended as only one additional lesion was identified. Therefore, bhPET has currently no indication in patients with NET. If technical improvements regarding PET/CT scanner sensitivity are available, bhPET should be reevaluated in the future.

Topics: Adult; Aged; Aged, 80 and over; Breath Holding; Female; Humans; Male; Middle Aged; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron Emission Tomography Computed Tomography

Functional imaging tests (FITs) detecting somatostatin receptor expression [i.e., somatostatin receptor scintigraphy, 68Ga-DOTA positron emission tomography/computed tomography (CT)] have a pivotal role in the diagnosis of neuroendocrine tumors (NETs), although their indication during follow-up still needs to be clarified.. Investigate the role of FITs after diagnosis of metastatic enteropancreatic NETs, identifying patients who might benefit from these exams.. Multicenter retrospective analysis of metastatic enteropancreatic NETs.. Analysis of imaging tests performed between January 1995 and December 2015 in Rome, Berlin, Milan, Marburg, or Graz.. One hundred forty-three patients with metastatic pancreatic NETs and small intestine NETs, at least 2-year follow-up, and positive FITs.. Patients had received CT every 6 months (unless clinical conditions and tumor behavior required shorter intervals) and FIT every 12 months.. Clinical usefulness of FITs, defined as changes in patient management (indication to biopsy, medical therapy, surgery, or further imaging tests) due only to FITs.. FITs affected management in 73.4% of patients, mostly when G2 vs G1 [odds ratio (OR), 2.40; 95% confidence interval (CI), 1.09 to 5.27; P = 0.03]. Changes were observed in a 12-month time frame especially with pancreatic NETs vs small intestine NETs (OR, 2.89; 95% CI, 1.09 - 7.67; P = 0.03) or metastases since diagnosis vs developed during follow-up (OR, 4.00; 95% CI, 1.43 to 11.17; P < 0.01).. FITs used in addition to CT in the follow-up of stage IV enteropancreatic NETs improve patient management (especially for G2 tumors). Follow-up program should be tailored according to tumor features.

Topics: Adult; Aged; Female; Follow-Up Studies; Humans; Intestinal Neoplasms; Intestine, Small; Lymph Nodes; Male; Middle Aged; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Pancreatic Neoplasms; Peritoneal Neoplasms; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals; Retrospective Studies

Epithelioid hemangioendothelioma (EHE) is a rare tumor originating from vascular endothelial or pre-endothelial cells. It has the potential to metastasize. We present the case of a 51-year-old woman with metastasizing EHE who underwent both F-FDG and Ga-DOTA-TATE PET/CT for staging of disease and for evaluation of targeted radionuclide therapy potential. On Ga-DOTA-TATE PET scans, intense tracer accumulation was observed in metastases. Besides the increased glucose metabolism in EHE, this case highlights the potential of Ga-DOTA-TATE PET/CT for restaging of EHE and the option of targeted radionuclide therapy in this entity.

Topics: Female; Fluorodeoxyglucose F18; Gene Expression Regulation, Neoplastic; Hemangioendothelioma, Epithelioid; Humans; Middle Aged; Molecular Imaging; Neoplasm Metastasis; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Receptors, Somatostatin

Metastatic neureoendocrine tumor to bone is well recognized. Typically, this has an appearance of multiple focal lesions. We present an example of diffuse skeletal involvement on both F-FDG PET/CT and Ga DOTATATE PET/CT with a pattern similar to the superscan appearance described on skeletal scintigraphy.

Topics: Aged; Fluorodeoxyglucose F18; Humans; Male; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Pancreatic Neoplasms; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals

Pheochromocytomas/paragangliomas are somatostatin receptor 2-overexpressing tumors. Ga-DOTA-peptide imaging has recently shown excellent results in the detection of metastatic lesions in these tumors. However, currently used Ga-DOTA peptides show different somatostatin receptor affinities. Here, we report the remarkable differences in a patient who was imaged with Ga-DOTANOC and Ga-DOTATATE PET/CT within a 7-month period. The patient presented with a nearly negative Ga-DOTANOC PET/CT scan, whereas on Ga-DOTATATE PET/CT, multiple highly positive lesions were identified.

Topics: Abdominal Neoplasms; Child; Female; Humans; Lung Neoplasms; Neoplasm Metastasis; Organometallic Compounds; Paraganglioma; Positron Emission Tomography Computed Tomography; Protein Binding; Radiopharmaceuticals; Receptors, Somatostatin; Succinate Dehydrogenase

Chordoma is a rare slow-growing neoplasm of neuroectodermal origin, which frequently recurs after removal and has the potential to metastasize. We present the case of a 53-year-old man with metastasizing chordoma who underwent F-FDG and Ga-DOTA-TATE PET/CT for restaging of disease and for evaluation of targeted radionuclide therapy potential. On both F-FDG and Ga-DOTA-TATE PET scans, increased tracer accumulation was observed in chordoma metastases. Besides the increased glucose metabolism in chordoma, this case highlights the potential of Ga-DOTA-TATE PET/CT for restaging of chordoma as well the option of targeted radionuclide therapy in this entity.

Topics: Chordoma; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Radiopharmaceuticals

(68)Ga-DOTATATE PET/CT scanning is a widely accepted method for imaging of neuroendocrine tumors. This cross-sectional study was performed to review the first 8 y of patient data from a large (68)Ga-DOTATATE PET/CT database in order to establish the impact of the modality on patient treatment and survival.. Demographic data, clinical outcome, survival, and change in management after (68)Ga-DOTATATE PET/CT were evaluated.. Between May 2005 and August 2013, 1,258 (68)Ga-DOTATATE PET/CT scans were obtained in 728 patients with confirmed or suspected neuroendocrine tumors. In most patients, the primary site was located in the midgut (26.4%). Analysis of NET grading in patients with known histopathologic data revealed that 35.7% had NET grade G1, 12.2% G2, and 8.7% G3. The most common indications for (68)Ga-DOTATATE PET/CT were follow-up (24.4%) and initial tumor staging (23.4%). Of the 1,258 (68)Ga-DOTATATE PET/CT scans completed, 75.7% were positive and 24.3% negative; there were 14 false-positive and 29 false-negative scans. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value were 97%, 95.1%, 96.6%, 98.5%, and 90.4%, respectively. In 40.9% of patients, the treatment plan was changed after the scans, owing mainly to new, unexpected findings. Statistically significant differences in survival were shown between patients with G1, G2, and G3 grade tumors (P < 0.0001) and also between patients with bone metastasis versus patients with soft-tissue metastasis (P < 0.0001).. (68)Ga-DOTATATE PET/CT scanning is safe and influences management in a large proportion of patients. Prognosis was dependent on tumor grade, and the presence of bone metastasis was associated with worse overall survival.

Topics: Adolescent; Adult; Aged; Aged, 80 and over; Cross-Sectional Studies; Female; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron-Emission Tomography; Referral and Consultation; Survival Analysis; Tomography, X-Ray Computed; United Kingdom; Young Adult

Schmorl node (SN) is the herniation of the nucleus pulposus through the cartilaginous and bony endplate into the adjacent vertebral body. It is documented that SNs produce areas of moderately increased F-FDG uptake. We present a case of a patient with history of neuroendocrine tumor, who underwent Ga DOTATATE PET/CT for follow-up, showing increased focal vertebral uptake suggestive of bone metastasis. CT revealed typical findings of an SN. The presented case indicates that SNs should be considered when encountering focally increased skeletal uptake in Ga DOTATATE PET/CT studies, which can mimic metastasis in patients with history of neuroendocrine tumors.

Topics: Aged; Diagnosis, Differential; Humans; Intervertebral Disc Degeneration; Intervertebral Disc Displacement; Male; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed

We are reporting a case of a 55-year-old woman who was diagnosed as having a non-functioning pancreatic neuroendocrine neoplasm (NF-PNEN), the World Health Organization (WHO) low grade (G1) with liver metastases. In the staging process the positron emission tomography - computed tomography with Fluorine-18-Fluorodeoxyglucose (F-FDG PET-CT) and spiral CT then the gallium-DOTA-octreotate positron emission tomography - computer tomography (⁶⁸Ga-DOTATATE PET-CT) shown difference in burden of disease. In first line therapy, everolimus (Afinitor®, Novartis Pharma GmbH, Germany) at the oral dose of 10 mg once daily and octreotide long-acting release (Sandostatin LAR®) 30 mg i.m. every 4 weeks were administered. Then, due to disease progression - radioisotope therapy with b-emitter Yttrium-90 (⁹⁰Y). Based on this experience and on the review of the literature, we recommend that the discrepancy between the imaging studies could be due to heterogeneity of proliferation rate and somatostatin receptors (SSTR) expression within a primary PNEN and metastases. Therefore in such cases of advanced PNEN WHO G1 in the lack of response to everolimus and octreotide LAR administration isotope therapy without a prior chemotherapy should be considered as a palliative treatment according to ESMO Clinical Practice Guidelines and Polish Network of Neuroendocrine Tumors.

Topics: Female; Fluorodeoxyglucose F18; Humans; Middle Aged; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Pancreatic Neoplasms; Positron-Emission Tomography; Tomography, X-Ray Computed

Despite initial responsiveness to both chemotherapy and radiotherapy, small cell lung cancer (SCLC) commonly relapses within months. Although neuroendocrine characteristics may be difficult to demonstrate in individual cases, a relevant expression of somatostatin receptors (SSTR) on the cell surface has been described. We aimed to evaluate the prognostic value of SSTR-expression in advanced SCLC. We further examined pre-requisites for successful peptide receptor radionuclide therapy (PRRT). 21 patients with extensive stage SCLC were enrolled. All patients underwent positron emission tomography/computed tomography (PET/CT) with 68Ga-DOTATATE to select patients for SSTR-directed therapy. PET scans were visually and semi-quantitatively assessed and compared to SSTR2a and SSTR5 expression in biopsy samples. Peak standardized uptake values (SUVpeak) of tumors as well as tumor-to-liver ratios were correlated to progression-free (PFS) and overall survival (OS). In 4/21 patients all SCLC lesions were PET-positive. 6/21 subjects were rated "intermediate" with the majority of lesions positive, the remaining 11/21 patients were PET-negative. PET-positivity correlated well with histologic SSTR2a, but not with SSTR5 expression. Neither PET-positivity nor SUVpeak were predictors of PFS or OS. In 4 patients with intensive SSTR2a-receptor expression, PRRT was performed with one partial response and one stable disease, respectively. SSTR-expression as detected by 68Ga-DOTATATE-PET and/or histology is not predictive of PFS or OS in patients with advanced SCLC. However, in patients exhibiting sufficient tracer uptake, PRRT might be a treatment option given its low toxicity and the absence of effective alternatives.

Topics: Adult; Aged; Female; Follow-Up Studies; Humans; Lung Neoplasms; Male; Middle Aged; Neoplasm Metastasis; Neoplasm Staging; Organometallic Compounds; Positron Emission Tomography Computed Tomography; Prognosis; Radiopharmaceuticals; Receptors, Somatostatin; Small Cell Lung Carcinoma

Differentiated thyroid carcinoma (DTC) has good prognosis but 5% of the patients already have distant metastasis at the diagnosis. Tumour cells can lose their iodine uptake ability and enter a state of dedifferentiation. Treatment for differentiated thyroid carcinoma that is not suitable for the local surgery and unresponsive to radioactive iodine uptake is not always easy for physicians. We present a case of a 64-year-old man who had total thyroidectomy surgery and central lymph node dissection with diagnosis of multinodular goitre disease. Histopathological evaluation was papillary thyroid cancer with tall cell variant. Treatment using 150 mCi radioiodine was administered to the patient three times but could not effect a cure. We performed Ga-68 labelled DOTATE (synthetic somatostatin analogue peptide). This provided a good outcome. As evident from our case, Lu-177 radionuclide labelled synthetic somatostatin analogue peptides have therapeutic effect on radioiodine refractory DTC, as an alternative treatment modality.

Topics: Aged; Carcinoma; Carcinoma, Papillary; Goiter, Nodular; Humans; Iodine Radioisotopes; Male; Neoplasm Metastasis; Octreotide; Organometallic Compounds; Peptides; Positron Emission Tomography Computed Tomography; Somatostatin; Thyroid Cancer, Papillary; Thyroid Neoplasms; Thyroidectomy

Ga DOTATATE PET/CT is an imaging technique used in the diagnosis of neuroendocrine tumors. We report a case of 66-year-old woman with a history of surgically removed renal cell carcinoma who presented for a DOTATATE PET/CT scan to characterize a newly diagnosed pancreatic lesion. DOTATATE-avid lesions were identified in the thyroid gland and pancreas. Subsequent biopsy confirmed the diagnosis of metastatic renal cell carcinoma at both sites. It is important to be aware that tumors other than neuroendocrine tumors may also show uptake on DOTATATE PET/CT scan. A biopsy may be required if lesions are identified at atypical sites.

Topics: Aged; Biological Transport; Carcinoma, Renal Cell; Female; Humans; Neoplasm Metastasis; Organometallic Compounds; Pancreatic Neoplasms; Positron Emission Tomography Computed Tomography; Thyroid Neoplasms

We describe somatostatin receptor targeted imaging findings in a 56-year-old woman with elevated serum thyroglobulin and radioiodine negative DTC fibular metastasis. The fibular lesion was biopsy proven of poorly differentiated thyroid carcinoma and demonstrated high grade uptake on Tc-HYNIC-TOC scintigraphy. She opted for sorafenib therapy for progressively increasing fibular swelling and was started on 400 mg daily followed by dose escalation to 400 mg twice daily. At 17 months after sorafenib initiation, Ga DOTATATE PET/CT demonstrated necrosis of the fibular lesion; however, new lesions were documented in lower dorsal and lumbar vertebrae and skull, based upon which sorafenib withdrawal was contemplated.

Topics: Female; Humans; Middle Aged; Neoplasm Metastasis; Niacinamide; Organometallic Compounds; Phenylurea Compounds; Positron Emission Tomography Computed Tomography; Sorafenib; Thyroid Neoplasms; Treatment Outcome

We aimed to compare the efficacies of gallium-68 (68Ga) DOTATATE PET-computed tomography (CT), fluorine-18 fluorodeoxyglucose (18F-FDG) PET-CT and technetium-99m (99mTc)-(V)DMSA scintigraphy in the detection of residual/metastatic medullary thyroid carcinoma (MTC).. We retrospectively evaluated DOTATATE PET-CT, 18F-FDG PET-CT and (V)DMSA scintigraphy of 22 MTC patients, all taken within a 6-month period in each patient, because of high levels of calcitonin (Ct) and carcinoembryonic antigen (CEA). We investigated the relationships between the results of the imaging modalities and tumour marker levels and the sporadic versus hereditary nature of the disease, as well as the effect of imaging results on patient management.. The ages of the patients at diagnosis were between 20 and 69 years. The median levels of Ct and CEA were 871.5 pg/ml and 11.2 ng/ml, respectively. In the patient-based analysis, we observed at least one focus of abnormal uptake in 15 of 22 DOTATATE PET-CT (68.2% sensitivity), eight of 18 18F-FDG PET-CT (44.4% sensitivity) and five of 15 (V)DMSA scans (33.3% sensitivity). These data showed a significant difference between DOTATATE PET-CT and (V)DMSA scintigraphy (P=0.016), whereas the relationships between DOTATATE PET-CT and 18F-FDG PET-CT and between 18F-FDG PET-CT and (V)DMSA scintigraphy showed no significant differences (P>0.05). In the lesion-based analysis, 134 lesions were detected with DOTATATE PET-CT, 76 lesions with 18F-FDG PET-CT and nine lesions with (V)DMSA scintigraphy.. DOTATATE PET-CT is an efficient imaging modality in MTC patients with increased Ct and CEA (especially >1000 pg/ml and 50 ng/ml, respectively) for localizing recurrent or metastatic disease. 18F-FDG PET-CT can be performed if DOTATATE PET-CT is not available, but (V)DMSA scintigraphy is not recommended.

Topics: Adult; Aged; Biomarkers, Tumor; Carcinoma, Neuroendocrine; Female; Fluorodeoxyglucose F18; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neoplasm, Residual; Organometallic Compounds; Positron-Emission Tomography; Retrospective Studies; Technetium Tc 99m Dimercaptosuccinic Acid; Thyroid Neoplasms; Tomography, X-Ray Computed; Whole Body Imaging; Young Adult

Somatostatin receptor imaging with (68)Ga-DOTATATE PET/CT (DOTATATE) is increasingly used for managing patients with neuroendocrine tumors. The objective of this study was to determine referring physicians' perspectives on the impact of DOTATATE on the management of neuroendocrine tumors.. A set of 2 questionnaires (pre-PET and post-PET) was sent to the referring physicians of 100 consecutive patients with known or suspected neuroendocrine tumors, who were evaluated with DOTATATE. Questionnaires on 88 patients were returned (response rate, 88%). Referring physicians categorized the DOTATATE findings on the basis of the written PET reports as negative, positive, or equivocal for disease. The likelihood for metastatic disease was scored as low, moderate, or high. The intended management before and changes as a consequence of the PET study were indicated.. The indications for PET/CT were initial and subsequent treatment strategy assessments in 14% and 86% of patients, respectively. Referring physicians reported that DOTATATE led to a change in suspicion for metastatic disease in 21 patients (24%; increased and decreased suspicion in 9 [10%] and 12 [14%] patients, respectively). Intended management changes were reported in 53 of 88 (60%) patients. Twenty patients (23%) scheduled to undergo chemotherapy were switched to treatments without chemotherapy, and 6 (7%) were switched from watch-and-wait to other treatment strategies. Conversely, 5 patients (6%) were switched from their initial treatment strategy to watch-and-wait.. This survey of referring physicians demonstrates a substantial impact of DOTATATE on the intended management of patients with neuroendocrine tumors.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Image Interpretation, Computer-Assisted; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Physicians; Positron-Emission Tomography; Referral and Consultation; Research Report; Surveys and Questionnaires; Tomography, X-Ray Computed

Pancreatic neuroendocrine tumors (PNETs) represent a small percentage of all pancreatic malignancies, and most of these present as metastatic disease. Somatostatin receptor scintigraphy had been used successfully for the assessment of patients with NET. Somatostatin receptor scintigraphy is indispensable for localization of ectopic NET and the distribution of NET throughout the body.

Topics: Female; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Organometallic Compounds; Pancreatic Neoplasms; Paraganglioma; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed

⁶⁸Ga DOTATATE PET/CT is a well-established method in the diagnostic workup of neuroendocrine tumors. We report the case of a 15-year-old adolescent boy with histologically proven appendiceal carcinoid tumor referred for ⁶⁸Ga DOTATATE PET/CT to identify residual or metastatic disease. PET images showed increased tracer uptake in the body of T4 vertebra. This uptake could be misdiagnosed for bone metastasis, but CT characteristic appearance was in keeping with vertebral hemangioma. Both bone metastasis in carcinoid tumor and bone hemangiomas in adolescents are rare conditions, but the combined metabolic and morphological information on PET/CT can lead to the correct diagnosis.

Topics: Adolescent; Carcinoid Tumor; Hemangioma; Humans; Male; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Spinal Neoplasms; Tomography, X-Ray Computed

Patients with succinate dehydrogenase subunit B(SDHB) mutation-related pheochromocytoma/paraganglioma (PHEO/PGL) are at a higher risk for metastatic disease than other hereditary PHEOs/PGLs. Current therapeutic approaches are limited, but the best outcomes are based on the early and proper detection of as many lesions as possible. Because PHEOs/PGLs overexpress somatostatin receptor 2 (SSTR2), the goal of our study was to assess the clinical utility of [(68)Ga]-DOTA(0)-Tyr(3)-octreotate ([(68)Ga]-DOTATATE) positron emission tomography/computed tomography (PET/CT) and to evaluate its diagnostic utility in comparison with the currently recommended functional imaging modalities [(18)F]-fluorodopamine ([(18)F]-FDA), [(18)F]-fluorodihydroxyphenylalanine ([(18)F]-FDOPA), [(18)F]-fluoro-2-deoxy-d-glucose ([(18)F]- FDG) PET/CT as well as CT/MRI.. [(68)Ga]-DOTATATE PET/CT was prospectively performed in 17 patients with SDHB-related metastatic PHEOs/PGLs. All patients also underwent [(18)F]-FDG PET/CT and CT/MRI, with 16 of the 17 patients also receiving [(18)F]-FDOPA and [(18)F]-FDA PET/CT scans. Detection rates of metastatic lesions were compared between all these functional imaging studies. A composite synthesis of all used functional and anatomical imaging studies served as the imaging comparator.. [(68)Ga]-DOTATATE PET/CT demonstrated a lesion-based detection rate of 98.6% [95% confidence interval (CI), 96.5%-99.5%], [(18)F]-FDG, [(18)F]-FDOPA, [(18)F]-FDA PET/CT, and CT/MRI showed detection rates of 85.8% (CI, 81.3%-89.4%; P < 0.01), 61.4% (CI, 55.6%-66.9%; P < 0.01), 51.9% (CI, 46.1%-57.7%; P < 0.01), and 84.8% (CI, 80.0%-88.5%; P < 0.01), respectively.. [(68)Ga]-DOTATATE PET/CT showed a significantly superior detection rate to all other functional and anatomical imaging modalities and may represent the preferred future imaging modality in the evaluation of SDHB-related metastatic PHEO/PGL.

Topics: Adult; Female; Humans; Male; Middle Aged; Mutation; Neoplasm Metastasis; Organometallic Compounds; Paraganglioma; Pheochromocytoma; Positron-Emission Tomography; Radiopharmaceuticals; Sensitivity and Specificity; Succinate Dehydrogenase; Tomography, X-Ray Computed; Young Adult

The aim of this study was to define the frequency of neuroendocrine neoplasia (NEN) metastasis sites based on the primary lesion and create a database of SUVmax as a marker of human SSTR (somatostatin receptors) expression by semiquantitative analysis in vivo Ga DOTATATE PET/CT.. Two hundred forty-five patients, 89 men and 156 women (mean [SD] age, 56.1 [12.8]), were imaged 60 to 70 minutes after 120 to 200 MBq (3.2-5.4 mCi) Ga DOTATATE injection using a Siemens Medical Solutions Biograph 64 PET/CT TruePoint. Visual assessments were made using a multimodality workstation, and sites of increased uptake were recorded. Pathological Ga DOTATATE uptake was quantified using semiquantitative analysis (SUVmax).. In patients with unknown primary tumors, Ga DOTATATE PET/CT revealed primary location in 92% (pancreas, 47%; intestines, 28%; and lung, 17%).Metastases, with respect to the primary sites, were predominantly in the liver (33% vs 49% vs 40%), lymph nodes (24% vs 34% vs 25%), and bone (10% vs 20% vs 30%). The SUVmax of metastases (mean [SD]) was highest in the liver (28.7 [23.5]), followed by the adrenal glands (24.7 [9.7]), bone (24.1 [36.8]), lymph nodes (22.5 [24.5]), pancreas (24.9 [28.1]), peritoneum (21.9 [24]), and the brain (4.6 [2.9]).. Ga DOTATATE PET/CT is very useful in the localization of NEN primary tumors. Ga DOTATATE PET/CT allows for visualizations of bone and lymph node metastases, not detected by any other modalities, which provides better staging and changes the clinical decision in approximately one third of patients.Our study shows that pancreatic NEN presented statistically a significantly lower frequency of bone metastases in comparison to lung and intestinal NEN. No significant frequency of metastases in the liver and lymph nodes based on primary tumors was observed.

Topics: Adult; Aged; Data Interpretation, Statistical; Female; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Tomography, X-Ray Computed

Gastroenteropancreatic neuroendocrine tumors (GEPNETs) are indolent neoplasms presenting unpredictable and unusual biologic behavior that causes many clinical challenges. Tumor size, existence of metastasis, and histopathologic classification remain incapable in terms of treatment decision and prognosis estimation. This study aimed to compare (68)Ga-DOTATATE and (18)F-FDG PET/CT in GEPNETs and to investigate the relation between the complementary PET/CT results and histopathologic findings in the management of therapy, particularly in intermediate-grade patients.. The relation between complementary (68)Ga-DOTATATE and (18)F-FDG PET/CT results of 27 GEPNET patients (mean age, 56 y; age range, 33-79 y) and histopathologic findings was evaluated according to grade and localization using standardized maximum uptake values and Ki67 indices. Grade 2 (G2) patients were further evaluated in 2 groups as G2a (3%-9%) and G2b (10%-20%) according to Ki67 indices.. The sensitivity of (68)Ga-DOTATATE and (18)F-FDG PET/CT was 95% and 37%, respectively, and the positive predictive values were 93.8% and 36.2%, respectively. The sensitivity in detecting liver metastasis, lymph nodes, bone metastasis, and primary lesion was 95%, 95%, 90%, and 93% for (68)Ga-DOTATATE and 40%, 28%, 28%, and 75% for (18)F-FDG, respectively. Statistically significant differences were found between grades 1-2, 2a-2b, and 1-2b with respect to (68)Ga-DOTATATE PET/CT as well as between 1-2a and 1-2b with respect to (18)F-FDG PET/CT. However, no statistical differences were found between 1 and 2a (P > 0.05) for (68)Ga-DOTATATE and 2a and 2b (P = 0.484) for (18)F-FDG. The impact of the combined (18)F-FDG and (68)Ga-DOTATATE PET/CT on the therapeutic decision was 59%.. Combined (68)Ga-DOTATATE and (18)F-FDG PET/CT is helpful in the individual therapeutic approach of GEPNETs and can overcome the shortcomings of histopathologic grading especially in intermediate-grade GEPNETs.

Topics: Adult; Aged; Female; Fluorodeoxyglucose F18; Humans; Image Processing, Computer-Assisted; Intestinal Neoplasms; Ki-67 Antigen; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Organometallic Compounds; Pancreatic Neoplasms; Positron-Emission Tomography; Prospective Studies; Sensitivity and Specificity; Stomach Neoplasms; Tomography, X-Ray Computed

Merkel cell carcinoma (MCC) is a rare but very aggressive neuroendocrine tumor of the skin in elderly patients with higher mortality compared with melanoma. No evidence-based standardized chemotherapy exists for metastasized patients.We report the case of an 87-year-old patient with the history of resection of a large MCC of the parietal scalp planned for radiotherapy and staged with FDG PET/CT showing disseminated distant metastases. Ga-DOTATATE PET/CT revealed more extensive tumor load compared with FDG, and due to the intensive expression of somatostatin receptors the patient qualified for Y DOTATOC therapy.

Topics: Aged, 80 and over; Carcinoma, Merkel Cell; Fluorodeoxyglucose F18; Humans; Multimodal Imaging; Neoplasm Metastasis; Organometallic Compounds; Positron-Emission Tomography; Skin Neoplasms; Tomography, X-Ray Computed

The aim of the study was to compare sequential (177)Lu-DOTA-TATE planar scans ((177)Lu-DOTA-TATE) in patients with metastasized neuroendocrine tumours (NET) acquired during peptide receptor radionuclide therapy (PRRT) for dosimetry purposes with the pre-therapeutic (68)Ga-DOTA-TATE positron emission tomography (PET)/CT ((68)Ga-DOTA-TATE) maximum intensity projection (MIP) images obtained in the same patients concerning the sensitivity of the different methods.. A total of 44 patients (59 ± 11 years old) with biopsy-proven NET underwent (68)Ga-DOTA-TATE and (177)Lu-DOTA-TATE imaging within 7.9 ± 7.5 days between the two examinations. (177)Lu-DOTA-TATE planar images were acquired at 0.5, 2, 24, 48 and 72 h post-injection; lesions were given a score from 0 to 4 depending on the uptake of the radiopharmaceutical (0 being lowest and 4 highest). The number of tumour lesions which were identified on (177)Lu-DOTA-TATE scans (in relation to the acquisition time after injection of the therapeutic dose as well as with regard to the body region) was compared to those detected on (68)Ga-DOTA-TATE studies obtained before PRRT.. A total of 318 lesions were detected; 280 (88%) lesions were concordant. Among the discordant lesions, 29 were (68)Ga-DOTA-TATE positive and (177)Lu-DOTA-TATE negative, whereas 9 were (68)Ga-DOTA-TATE negative and (177)Lu-DOTA-TATE positive. The sensitivity, positive predictive value and accuracy for (177)Lu-DOTA-TATE as compared to (68)Ga-DOTA-TATE were 91, 97 and 88%, respectively. Significantly more lesions were seen on the delayed (72 h) (177)Lu-DOTA-TATE images (91%) as compared to the immediate (30 min) images (68%). The highest concordance was observed for bone metastases (97%) and the lowest for head/neck lesions (75%). Concordant lesions (n = 77; mean size 3.8 cm) were significantly larger than discordant lesions (n = 38; mean size 1.6 cm) (p < 0.05). No such significance was found for differences in maximum standardized uptake value (SUV(max)). However, concordant liver lesions with a score from 1 to 3 in the 72-h (177)Lu-DOTA-TATE scan had a lower SUV(max) (n = 23; mean 10.9) than those metastases with a score of 4 (n = 97; mean SUV(max) 18) (p < 0.05).. Although (177)Lu-DOTA-TATE planar dosimetry scans exhibited a very good sensitivity for the detection of metastases, they failed to pick up 9% of lesions seen on the (68)Ga-DOTA-TATE PET/CT. Three-dimensional dosimetry using single photon emission computed tomography/CT could be applied to investigate this issue further. Delayed (72 h) images are most suitable for drawing regions of interest for dosimetric calculations.

Topics: Adult; Aged; Aged, 80 and over; Female; Humans; Male; Middle Aged; Multimodal Imaging; Neoplasm Metastasis; Neuroendocrine Tumors; Octreotide; Organometallic Compounds; Positron-Emission Tomography; Radiometry; Receptors, Peptide; Retrospective Studies; Time Factors; Tomography, X-Ray Computed; Young Adult