A 66-year-old man with metastatic castration-resistant prostate adenocarcinoma experienced a rising PSA after multiple systemic therapies and radiation therapy to the cervical and thoracic spine for bone metastases. F-18 piflufolastat (Pylarify) PSMA PET/CT demonstrated widespread metastases, involving bones, lungs, mediastinal and hilar lymph nodes, liver, and intracranial and intraspinal sites. He subsequently developed worsening neurological symptoms. Brain MRI fused with PSMA PET revealed numerous radiotracer-avid scattered leptomeningeal enhancing foci intracranially. Cervical spine MRI fused with PSMA PET demonstrated multifocal radiotracer-avid intradural, extramedullary enhancing lesions. Biopsy of cervical intradural lesions confirmed metastatic prostate carcinoma.

A 68-year-old woman with history of bilateral breast cancer was referred for F-18 fluoroestradiol (F-18 FES) PET/CT to evaluate sclerotic osseous lesions seen on surveillance CT scan. F-18 FES PET/CT showed no focal abnormal increased radiotracer uptake at the bilateral breast, and no suspicious radiotracer-avid lymph nodes or osseous lesions. The same F-18 FES PET/CT showed focal increased radiotracer uptake at the stomach fundus. A follow-up F-18 FDG PET/CT showed no suspicious focal hypermetabolic activity in the stomach. An endoscopic biopsy identified gastric adenocarcinoma.

Glioblastoma is a high-grade CNS neoplasm, which demonstrates resistance to the current forms of therapy and commonly recurs with poor prognosis. This mandates the call for diagnostic accuracy and development of new treatment strategies. Current literature provides strong evidence that F18-FLT PET, amino acid PET (with C11 MET, F18-FDOPA, F18-FET, F18-fluciclovine), PSMA PET, and FAPI PET imaging are more advantageous than F-18 FDG, demonstrating low background activity and high tumor-to-normal brain tissue ratio, promising for the early and accurate detection of GBM recurrence. The implementation of radiomics in the PET imaging interpretation has the potential to differentiate high-grade gliomas from low-grade gliomas. These PET radiotracers could also benefit in the assessment of treatment response and distinguishing tumor progression from treatment-related changes. The development of PET tracers assessing hypoxia is of considerable clinical value in the detection and management of treatment-resistant GBM. Further, PET imaging of the immune system provides significant insight into the evaluation of immune response to GBM and imaging PD-L1 expression. Additionally, there are promising targets for theranostics in the management of GBM. One especially promising target is PSMA, with Ga-68 PSMA PET for imaging and Lu-177 PSMA for systemically targeted radioimmunotherapry. The other potential target for theranostics in GBM is FAPI, using FAPI PET for imaging and Lu-177- labeled FAPI radiopharmaceuticals for therapy.

The differential diagnosis of sinonasal lesions includes benign and malignant disease. Current radiologic diagnosis depends on the complementary roles of CT and MRI. PET/CT has been widely utilized for diagnosis and staging of various types of tumors as well as assessing treatment response. This article summarizes distinguishing radiologic characteristics of sinonasal disease, including lesions that are FDG avid (squamous cell carcinoma, lymphoma, inverted papilloma, rhabdomyosarcoma, osteosarcoma, and sinusitis), lesions that express somatostatin receptors (meningioma, esthesioneuroblastoma, and juvenile nasopharyngeal angiofibroma), and lesions that are not FDG avid (mucocele, mucus retention cyst, and sinus meningoencephalocele). Furthermore, PET/MRI may better facilitate the diagnosis of sinonasal disease.

ABSTRACT:A 60-year-old man with a history of end-stage renal disease received renal transplant and had decreasing renal function 4 months later. Nuclear medicine renal flow and functional study showed severely decreased blood flow and decreased function of the right renal allograft. There was focal increased radiotracer uptake at blood flow phase around the anastomosis of the renal allograft artery and the right external iliac artery. CT angiogram revealed right external iliac artery pseudoaneurysm. Interventional radiology angiography reconfirmed the pseudoaneurysm and revealed stenosis at the proximal transplant renal artery. After stent placement, however, there was worse renal allograft blood flow.

ABSTRACT:A 66-year-old woman had an episode of pancreatitis with symptoms starting in October 2023. MRI showed an enhancing soft tissue mass along the superior border of the pancreatic body, as well as signal changes in the pancreatic body and the tail consistent with pancreatitis. The 68 Ga-DOTATATE PET/CT demonstrated intense radiotracer uptake within the peripancreatic soft tissue mass, significantly greater than the spleen background. Biopsy of this peripancreatic mass revealed well-differentiated grade 1 neuroendocrine tumor. The body and tail of the pancreas showed diffusely increased 68 Ga-DOTATATE uptake but obviously lower than the peripancreatic neuroendocrine tumor, consistent with pancreatitis.

Background and Purpose: Paragangliomas (PGLs) are rare neuroendocrine tumors with imaging features that can overlap with other entities. This study hypothesizes that given overexpression of somatostatin receptor (SSTR) 2, PGLs can be differentiated on Ga-68 DOTATATE positron emission tomography/computed tomography (PET/CT) from other benign or malignant lesions. Materials and Methods: Ninety-six patients with known tumors of the head and neck who underwent Ga-68 DOTATATE PET/CT from May 2017 to December 2021 were retrospectively reviewed from a single institution. Of these, 43 patients had histopathological confirmation and 66 positive lesions were discovered on PET/CT. For each lesion, the SUV max, the SUV lesion to liver ratio, and the SUV lesion to spleen ratio were analyzed. Results: PGLs (n = 37) showed the most intense uptake, and the mean of SUVmax was 69.3 (range 3.7–225.9). Metastatic PGL and metastasis from other neuroendocrine tumors (n = 13) demonstrated intermediate uptake, the mean of SUVmax was 15.16 (range 2.3–40.3). Meningiomas (n = 3) had intermediate uptake, and the mean of SUVmax was 12.37 (range 2.5–19.4). One patient with esthesioneuroblastoma had 5 lesions in the head and neck, and the mean of SUVmax was 18.9 (range 6.9–49.4). Schwannomas (n = 4) had very low uptake, and the mean of SUVmax was 1.75 (range 1.1–2.2). Other rare cases with low uptake included 1 each of osteosarcoma, acinic cell carcinoma, ectopic thyroid tissue, and plasmacytoma, and the mean of SUVmax was 4.75 (range 2.3–6.1). Conclusions: Ga-68 DOTATATE PET/CT can be a useful adjunct in differentiating tumors in the head and neck. PGLs demonstrate the highest uptake. Meningioma, esthesioneuroblastoma, and neuroendocrine tumor metastasis have intermediate uptake. Schwannomas and other rare tumors exhibit low uptake.

Hematopoietic stem cell transplantation (HSCT) is an effective treatment for various types of hereditary hematologic disease, hematological malignancy, primary immunodeficiency and metabolic disease. Thyroid dysfunction is a common complication of HSCT, which situation is mainly manifested as hypothyroidism and rarely as hyperthyroidism. This report presents a 28-year-old man who developed hyperthyroidism 9 years after sibling allogeneic HSCT, which was most likely caused by chronic GVHD. In the meantime, the patient also suffered from liver dysfunction and pancytopenia, for which he was inappropriate to take antithyroid drugs (ATD) for treatment of hyperthyroidism. The patient was orally administered 259 MBq 131I, an individualized dose. The symptoms of hyperthyroidism were mitigated by 131I treatment.

The PERCIST criteria is a reliable and useful technique in evaluating treatment response for the primary anal cancer as well as the inguinal and pelvic lymphadenopathy. The Nigro protocol is a promising combined chemoradiation therapy strategy for the anal cancer patients with most demonstrating complete metabolic response or partial metabolic response on the initial post treatment FDG PET-CT scan.

ABSTRACT:A 64-year-old woman with metastatic papillary thyroid cancer underwent a total thyroidectomy followed by 2 courses of 131I therapy. The posttherapeutic whole-body scan after the second dose of 131I therapy showed multifocal bone metastasis. In addition, there is focal abnormal intense radiotracer uptake at the right inguinal region. SPECT/CT revealed that this abnormal focal radioactivity was from a superficial skin lesion. Further physical examination revealed a raised, approximately 1-cm, irregular grayish-brown lesion on the right groin skin. Histopathological examination confirmed the diagnosis of basal cell papilloma (seborrheic keratosis).

The patient was a 61-year-old man with a history of neck pain starting around October 2019. CT of the neck showed a lytic lesion at the right skull base. Subsequent MRI demonstrated an enhancing destructive mass in the right skull base centered in the occipital bone and condyle involving the jugular foramen and hypoglossal canal. An F-FDG PET/CT was performed showing increased FDG uptake in the right jugular foramen tumor. In addition, a PET/CT with Ga-[DOTA-Tyr3]-octreotate (Ga-DOTATATE) demonstrated a Ga-DOTATATE-avid lesion in the right jugular foramen eroding the adjacent osseous structures. Biopsy revealed a plasmacytoma and not paraganglioma.

After applying PERCIST to our institutional study cohort, the use of post-treatment PET-CT imaging to predict outcomes for this patient population remains unproven.

1277 Objectives: Radium-223 dichloride (Ra-223 Xofigo) is a treatment option for metastatic castrate-resistant prostate cancer (mCRPC) with bone metastases. It is unclear whether a rising PSA during and after Xofigo therapy is due to bone and/or soft tissue disease progression or a flare response. To answer this question, this retrospective study evaluated alkaline phosphatase (ALP) and PSA levels, along with concomitant bone scan and CT observations. Methods: A total of 30 patients diagnosed with mCRPC with bone metastases were treated with Ra-223 dichloride between July 2014 and September 2019. Twenty-four of 30 patients had PSA assessment, ALP assessment, bone scan and CT chest, abdomen and pelvis acquired before the initiation of therapy as the baseline, between injections, and after finishing Xofigo therapy. Six patients were lost to follow-up after Xofigo therapy. Results: Among the 24 patients who had follow-up, 10 patients completed all 6 treatments of Xofigo, and 14 patients completed fewer treatments (between 1 and 5 cycles). On average, the ALP decreased by 29% at the nadir and 13% at completion, and the nadir occurred between the 3rd and 4th cycles. The PSA increased on average by 44% in between each cycle, and the lowest PSA was observed between the 1st and 2nd cycles. Three out of 24 patients (12.5%) PSA levels decreased after Xofigo therapy, and their ALP levels decreased or were stable after therapy. Two of these 3 patients had PSA flare phenomenon whereby the PSA increased initially after the 1st or 2nd cycles, and then decreased below baseline after the last treatment. Twenty-one out of 24 patients (87.5%) PSA levels increased during and after Xofigo therapy. Among these 21 patients whose PSA increased, 15 patients (71.4%) ALP levels were stable or decreased after completing therapy. The majority of these patients (11 out of 15) demonstrated soft tissue disease progression on CT scan, including metastases to the adrenal gland, liver, lung, lymph nodes or brain. The bone scans performed on these 15 patients showed variable responses, for example, 1 patient demonstrated improvement, 2 patients had stable bone scan findings, 4 patients showed mixed response (with some foci showing interval improvement and other foci demonstrating interval progression), and 8 patients demonstrated bone disease progression. Among the 21 patients whose PSA increased after therapy, 6 patients (28.6%) ALP levels increased, and their bone scans demonstrated progression (n=4) or mixed response (n=2). In addition, 5 of the 6 patients demonstrated soft tissue disease progression on CT with metastases to the adrenal gland, lung, liver, or lymph nodes. Conclusions: Most mCRPC patients (87.5%) in our study demonstrated increasing PSA levels during and after Ra-223 dichloride therapy. Despite a rising PSA, however, the majority (71.4%) of patients had ALP levels that were stable or decreased, and these patients were more likely to exhibit soft tissue disease progression on CT, with a variable response on bone scan. Patients with an increase in both PSA and ALP levels after Ra-223 dichloride therapy demonstrated disease progression in both the bones and soft tissues.

A 66-year-old man was diagnosed with metastatic prostate cancer to the bones. The patient started(223)Ra-dichloride (Xofigo) therapy in April 2019.Tc-99m-MDP bone scan and(18)F-fluciclovine (Axumin) PET/CT showed discordant but overall complementary findings that indicated disease progression after 5 doses of Xofigo therapy. The patient's prostate-specific antigen increased from 33.81 ng/mL at baseline before Xofigo therapy and up to 394.3 ng/mL after the fifth dose of Xofigo treatment. Because of disease progression, Xofigo therapy was discontinued.

A 69-year-old man presented with lower urinary tract symptoms and prostate biopsy showed prostate cancer. F-Fluciclovine PET/CT revealed abnormal increased radiotracer uptake within the prostate gland, and multiple osseous structures, suspicious for tumoral involvement. Incidentally, an expansile soft tissue density mass arising from sella turcica demonstrated increased radiotracer activity. MRI showed a lobulated enhancing mass centered in the sella and eroding into the sphenoid sinus. The differential diagnosis includes pituitary macroadenoma versus prostate cancer metastasis. The tumor was resected and the pathological diagnosis was pituitary adenoma.

A 79-year-old man had carcinoid syndrome and bilateral pulmonary nodules, which were biopsy confirmed as well-differentiated neuroendocrine tumor. PET/CT with Ga-[DOTA-Tyr]-octreotate (Ga-DOTATATE) showed multiple Ga-DOTATATE-avid bilateral pulmonary nodules, left hilar lymph node, as well as diffuse increased Ga-DOTATATE uptake in the prostate. A review of the history revealed that this patient had elevated prostate-specific antigen level. The prostate biopsy did not reveal evidence of prostate cancer but showed benign prostate hyperplasia.

It is unusual to observe I accumulation in the gallbladder and high-grade serous ovarian adenocarcinoma during posttherapeutic I scan. We report the case of a 55-year-old woman with papillary thyroid cancer, who received total thyroidectomy and then 3 courses of I therapy. The posttherapeutic whole-body scan after the third dose of I therapy revealed abnormal I uptake in the right upper abdomen, overlapping the liver, and the pelvis. Further SPECT/CT imaging found that they were from an enlarged gallbladder and a large pelvic complex solid and cystic mass, which was pathologically confirmed as bilateral high-grade serous ovarian adenocarcinoma.

Positron emission tomography/computed tomography (PET/CT) has been widely utilized in the clinic and in animal research for detecting and serially staging various types of neoplasms, including lymphomas, melanoma, lung cancer, thyroid cancer, head and neck cancer, esophagus and gastric cancer, colorectal cancer, pancreatic cancer, gynecologic cancers, osteosarcoma, breast cancer, pheochromocytoma [1-7]. The most commonly utilized radiopharmaceutical for PET/CT is 2-deoxy-2-[18F] fluoroglucose (18F-FDG), a glucose analogue that is taken up by the cell through glucose transporters, and then phosphorylated within the cell reflecting the rate of glucose metabolism. Compared with normal cells, cancer cells have increased glucose metabolism. Accordingly, PET/CT imaging with 18F-FDG is able to reveal an increased glucose metabolism in tumors and to identify both primary neoplasm and their metastases.