Head-to-Head Comparison of 68Ga-NODAGA-JR11 and 68Ga-DOTATATE PET/CT in Patients with Metastatic, Well-Differentiated Neuroendocrine Tumors: Interim Analysis of a Prospective Bicenter Study

The current study aimed to compare 68Ga-NODAGA-Cpa-cyclo(d-Cys-amino-Phe-hydroorotic acid-d-4-amino-Phe(carbamoyl)-Lys-Thr-Cys)-d-Tyr-NH2 (JR11) and 68Ga-DOTATATE PET/CT in patients with metastatic, well-differentiated neuroendocrine tumors. Methods: A prospective bicenter study aimed at enrolling 100 patients with histologically proven, metastatic or unresectable, well-differentiated neuroendocrine tumors was conducted. The first 48 patients represented the study cohort. Each patient received 68Ga-DOTATATE on the first day and 68Ga-NODAGA-JR11 on the second day. Whole-body PET/CT scans were performed at 40-60 min after injection. Normal-organ uptake, lesion numbers, lesion uptake, and sensitivity were compared. The potential impact on clinical management was also determined. Results: Overall, 68Ga-NODAGA-JR11 demonstrated lower background uptake in normal organs. Compared with 68Ga-DOTATATE, 68Ga-NODAGA-JR11 detected significantly more liver lesions (673 vs. 584, P = 0.002). The target-to-background ratio of liver lesions was significantly higher on 68Ga-NODAGA-JR11 (6.4 ± 8.7 vs. 3.1 ±2.6, P = 0.000). Comparable uptake was observed for primary tumors, bone lesions, and lymph node metastases. In total, 180 lesions were detected on conventional imaging in 15 patients; 165 and 139 lesions of them were positive on 68Ga-NODAGA-JR11 and 68Ga-DOTATATE, leading to a sensitivity of 91.7% and 77.2%, respectively. In 14.5% (7/48) of patients, 68Ga-NODAGA-JR11 PET might have a potential impact on clinical management. Conclusion: 68Ga-NODAGA-JR11 shows better sensitivity and a higher target-to-background ratio than 68Ga-DOTATATE. The detection of more lesions by the antagonist may have a potential impact on clinical management in a subgroup of patients.

Solitary Accessory Spleen-Like Metastasis Coexisted With Splenic Infarction Reveled on 18F-FDG PET/CT in a Hepatocellular Carcinoma Patient

ABSTRACT

Solitary parasplenic metastatic carcinoma may be misinterpreted as accessory spleen on CT images. In addition, elevated FDG uptake in the spleen may also mimic metastasis in patient with a history of carcinoma. Here we present a case of parasplenic metastasis coexisted with splenic infarction reveled on 18F-FDG PET/CT in a 51-year-old man with history of hepatocellular carcinoma.

A case of intrahepatic splenosis: usefulness of splenic scintigraphy

We report a 39-year-old male with intrahepatic and peritoneal splenosis, focusing on scintigraphic findings. Dynamic computed tomography (CT) showed a 3 cm lesion in the posterior right lobe of the liver with strong early phase enhancement that was homogenous to the liver enhancement in the late phase. A few enhancing nodules were also found in the peritoneum. On gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced dynamic magnetic resonance imaging (MRI), the hepatic lesion had abnormal signal on diffusion-weighted imaging, high signal intensity on T2-weighted imaging, and early enhancement with accumulation decline in the hepatocyte phase. CT and MRI findings of the hepatic lesion were similar to normal spleen. To rule out hepatic neuroendocrine tumor and peritoneal metastases, somatostatin receptor scintigraphy was performed and showed tracer accumulation in the hepatic lesion, which we considered a false positive. Splenic scintigraphy using Tc-99 m-phytate showed accumulation in the hepatic lesion and peritoneal nodules. Given the patient's history of splenic injury and splenectomy 15 years prior and the current imaging findings, we highly suspected splenosis. After surgical treatment, the patient was pathologically diagnosed with intrahepatic and peritoneal splenosis. Splenosis should be suspected when a patient has a history of trauma or abdominal surgery. Since intrahepatic splenosis presents as a nonspecific hypervascular lesion on CT and MRI, splenic scintigraphy should be considered in these patients. In addition Tc-99 m-phytate scintigraphy is easy to use and cost-effective.

Intrapancreatic accessory spleen false positive to 68Ga-Dotatoc: case report and literature review

Background

Intrapancreatic accessory spleen (IPAS) is an uncommon finding of pancreatic mass. Differential diagnosis with pancreatic tumor, especially with non-functional neuroendocrine tumor (NF-NET), may be very hard and sometimes it entails unnecessary surgery. A combination of CT scan, MRI, and nuclear medicine can confirm the diagnosis of IPAS. 68-Ga-Dotatoc PET/CT is the gold standard in NET diagnosis and it can allow to distinguish between IPAS and NET.

Case presentation

A 69-year-old man was admitted to our hospital for an incidental nodule in the tail of the pancreas with focal uptake of 68-Ga-dotatate at PET/CT. NET was suspected and open distal splenopancreatectomy was performed. Pathologic examination revealed an IPAS.

Conclusion

This is the second IPAS case in which a positive 68Ga-Dotatoc uptake led to a false diagnosis of pancreatic NET. Here is a proposal of a literature review.

Pancreatic accessory spleen. False positive with 99mTc-Octreotide

The case is presented on a patient with abdominal pain and suspicion of neuroendocrine tumor in the tail of the pancreas shown in the abdominal CT and MRI. Whole-body scintigraphy and abdominal SPECT/CT with ^99mTc-octreotide were performed that showed a nodular lesion partially on the posterior side of the pancreas tail. This nodule showed faint tracer uptake, and was reported as probable neuroendocrine tumor. Partial pancreatectomy and splenectomy were performed, and the histological study identified the lesion as an ectopic spleen. There are similar cases in the literature that match these findings, but this lesion is still frequently diagnosed after performing unnecessary surgery. When an asymptomatic intrapancreatic mass is detected, an accessory spleen should be considered and specific diagnostic techniques should be performed, such as labeled and denatured red blood cell SPECT/CT.