Alireza Rezaee

68Ga-PSMA-HBED Uptake on Cervicothoracic (Stellate) Ganglia, a Common Pitfall on PET/CT.

Ga-PSMA-HBED PET/CT showed promising results in staging and restaging of prostate cancer. However, nonspecific uptake has been reported in the celiac ganglia. In this case series, we showed faint radiotracer uptake on upper thoracic region in the location of cervicothoracic (stellate) ganglia. This ganglion is located anterior to the transverse process of C7 vertebra, inferior to subclavian artery, and superior to the neck of the first rib.

Giant Cell Tumor of the Tendon Sheath With Discordant Metabolism as a False Positive on Staging of Mantle Cell Lymphoma.

A baseline F-FDG PET/CT scan in a patient with mantle cell lymphoma showed diffuse minimally FDG-avid lymphadenopathy and splenomegaly. There was also a focus of uptake in the left subscapularis muscle without a CT correlate. A post-chemotherapy scan showed interval decrease in size, and resolution of FDG uptake, of the lymph nodes and spleen. Persistent activity was seen in the subscapularis muscle. Posttreatment biopsy of the FDG-avid lesion showed a benign giant cell tumor of tendon sheath. This case illustrates that a lesion with a markedly discordant SUV should raise suspicion for a second process.

Pediatric presentation of splenic marginal zone lymphoma on FDG PET/CT scan.

Splenic marginal zone lymphoma (SMZL) comprises about 1% of B-cell lymphomas and typically occurs after the age of 50 years. Pediatric SMZL is very rare, and no FDG PET/CT imaging of the disease has been reported. In the current study, a 4-year-old boy with biopsy-proven SMZL had FDG PET/CT for staging, which showed increased metabolic activity in the spleen and left cervical lymph nodes. A second FDG PET/CT for evaluation of treatment response showed complete resolution of abnormal FDG uptake in the nodes and spleen with decrease in size of the nodes.

Chapter 10 – Prostate Cancer

Prostate cancer is the second most common malignancy among men. In addition to clinical information, benign findings and pitfalls in PET/CT reading using various radiotracers, and teaching cases, this chapter reviews evidence-based recommendations regarding PET/CT examination in prostate cancer and compares them with statements in major clinical guidelines. The major guidelines do not support utilization of fludeoxyglucose (FDG) PET/CT for the evaluation of prostate cancer. However, according to evidence-based data, FDG PET/CT provides prognostic value and may be beneficial for therapy monitoring in castrate-resistant metastatic disease with poorly differentiated tumor. PET radiotracers, such as 11C- and 18F-choline and 11C-acetate, seem to be promising in staging of high-risk prostate cancer. They showed a good performance in the therapy monitoring of patients with metastatic prostate cancer. On the other hand, 68Ga-PSMA PET/CT is more sensitive than CT or MRI for the detection of metastatic disease in patients with intermediate-to high-risk prostate cancer, even at low serum prostate-specific antigen values. As another imaging method, 18F-NaF PET/CT is superior to conventional bone scintigraphy and provides excellent performance in the assessment of bone metastasis.

Gastroenteropancreatic Neuroendocrine Neoplasms

Neuroendocrine neoplasia (NEN) could arise from anywhere in the body but arises mainly (about 70%) from the gastroenteropancreatic (GEP) system. In addition to clinical information, benign findings, pitfalls in PET/CT reading using various radiotracers, and teaching cases, this chapter reviews evidence-based recommendations regarding PET/CT examination in NENs and compares them with statements in major clinical guidelines. High expression of predominantly SSTR-2 and SSTR-5 on more than 70% of gastrointestinal NENs makes them excellent targets for imaging with radiolabeled somatostatin analogues such as 111 In-octreotide scan. In patients with suspect thoracic and GEP-NETs, 68 Ga-somatostatin receptor PET/CT shows high sensitivity, specificity, and accuracy and should be considered as a first-line diagnostic imaging modality. It is also promising for assessing SSRTs before peptide receptor radiolabeled therapy (PRRT) and therapy evaluation after PRRT. As another modality, 18 F-DOPA PET/CT is an accurate method for diagnosing proven or suspected NENs. Given low proliferation and high differentiation, neuroendocrine tumors (NETs) are usually faintly FDG avid. But FDG PET/CT is recommended for staging and restaging of selected patients with poorly differentiated NENs, i.e., neuroendocrine carcinomas G3. FDG PET/CT may be useful to characterize tumor aggressiveness with higher FDG uptake (higher standard uptake values), which indicates a worse prognosis. Some other PET radiotracers are also used to image this kind of malignancy.

Chapter 8 – Lymphoma

Mature lymphoid neoplasms are simply divided into Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL); the latter is the sixth most common cancer and the ninth leading cause of death. In addition to clinical information, benign findings and pitfalls in fludeoxyglucose (FDG) PET/CT reading, and teaching cases, this chapter reviews evidence-based recommendations regarding PET/CT examination in lymphoma and compares them with statements in major clinical guidelines. There are abundant articles in the literature that discuss the outstanding role of FDG PET/CT in staging, restaging, therapy response assessment, and detection of transformation in HL and NHL. Its ability to predict prognosis in patients with lymphoma is also well addressed in the medical literature. According to evidence-based data, FDG PET/CT is also recommended for the evaluation of posttransplant lymphoproliferative disorders.

Chapter 2 – Lung Cancer

Lung cancer is the second most common cancer and the leading cause of cancer-related death in both genders. The role of fludeoxyglucose (FDG) PET/CT in investigating solitary pulmonary nodules as the standard diagnostic imaging modality is well documented. With higher sensitivity and specificity compared with CT, FDG PET/CT is a useful modality for staging and restaging of small cell and non-small cell lung cancers, as well as for the evaluation of corresponding lymph node metastases. In addition to clinical information, benign findings and pitfalls in FDG PET/CT reading, and teaching cases, this chapter reviews evidence-based recommendations regarding PET/CT examination in lung cancers and compares them with statements in major clinical guidelines. According to evidence-based data, this modality is also the standard choice to investigate response to treatment. It has also a prognostic value, for example, a higher maximum standardized uptake value (SUVmax) of the primary non-small cell lung cancer is associated with greater tumor invasiveness and postsurgical recurrence.

Chapter 7 – Hepatobiliary Cancer

Hepatocellular carcinoma (HCC) is the sixth most common malignancy in Asia and Africa and constitutes 70%–85% of primary liver cancers. In addition to clinical information, benign findings and pitfalls in PET/CT reading using various radiotracers, and teaching cases, this chapter reviews evidence-based recommendations regarding PET/CT examination in hepatobiliary cancers and compares them with statements in major clinical guidelines. According to evidence-based data, fludeoxyglucose (FDG) PET/CT was useful in ruling in extrahepatic metastases and valuable for ruling out recurrent HCC. Although radiolabeled choline PET/CT could be a valuable tool in detecting this malignancy, especially in well- to moderately differentiated lesions, poorly differentiated and higher-stage HCC could be more accurately evaluated with FDG and dual-tracer imaging. Cholangiocarcinoma is the second most common primary hepatic malignancy. Gallbladder cancer presents in the liver in 70% and with regional lymph node metastases in 50% of patients. FDG PET/CT has been demonstrated to be an accurate diagnostic imaging method in the assessment of both primary tumors. A positive PET/CT would lead to a decision not to operate on the patient. It is useful in detecting recurrent and metastatic disease in patients with abnormalities on CT or MRI.

Chapter 4 – Gastroesophageal Cancer

Gastric cancer is the fifth most common cancer worldwide. There is a widely accepted consensus of the usefulness of FDG PET/CT in staging and restaging of gastric cancer. In addition to clinical information, benign findings, pitfalls in FDG PET/CT reading, and teaching cases, this chapter reviews evidence-based recommendations regarding PET/CT examination in gastric and esophageal cancers and compares them with statements in major clinical guidelines. According to evidence-based data, this modality can evaluate gastric cancer more accurately and is helpful for evaluation of tumor biologic characteristics, detection of lymph node and distant metastases, assessment of tumor response to therapy. and prediction of prognosis. Esophageal cancer is the eighth most common cancer worldwide. According to evidence-based data, FDG PET/CT plays an important role in staging and restaging of esophageal cancer, as well as evaluation after neoadjuvant therapy. It is also a strong predictor of therapy response and an independent predictor of overall survival in patients with nonmetastatic esophageal cancer.

Chapter 6 – Colorectal Cancer

Colorectal cancer is the third most common type of malignancy worldwide. In addition to clinical information, benign findings and pitfalls in FDG PET/CT reading, and teaching cases, this chapter reviews evidence-based recommendations regarding PET/CT examination in colorectal cancers and compares them with statements in major clinical guidelines. According to evidence-based data, FDG PET/CT is appropriate for staging of stage IV disease, ruling out or detecting synchronous metastases, and restaging of patients, especially in cases of rising tumor markers or clinical suspicion of recurrence but equivocal findings on conventional imaging modalities.