Imaging-based non-invasive liver disease assessment for staging liver fibrosis in chronic liver disease: A systematic review supporting the AASLD Practice Guideline.

BACKGROUND AND AIMS: Transient elastography (TE), shear-wave elastography (SWE), and/or magnetic resonance elastography (MRE), each providing liver stiffness measurement (LSM), are the most studied imaging-based noninvasive liver disease assessment (NILDA) techniques. To support the American Association for the Study of Liver Diseases guidelines on NILDA, we summarized the evidence on the accuracy of these LSM methods to stage liver fibrosis (F). APPROACH AND RESULTS: A comprehensive search for studies assessing LSM by TE, SWE, or MRE for the identification of significant fibrosis (F2-4), advanced fibrosis (F3-4), or cirrhosis (F4), utilizing histopathology as standard of reference by liver disease etiology in adults or children from inception to April 2022 was performed. We excluded studies with <50 patients with a single disease entity and mixed liver disease etiologies (with the exception of HCV/HIV co-infection). Out of 9447 studies, 240 with 61,193 patients were included in this systematic review. In adults, sensitivities for the identification of F2-4 ranged from 51% to 95%, for F3-4 from 70% to 100%, and for F4 from 60% to 100% across all techniques/diseases, whereas specificities ranged from 36% to 100%, 74% to 100%, and 67% to 99%, respectively. The largest body of evidence available was for TE; MRE appeared to be the most accurate method. Imaging-based NILDA outperformed blood-based NILDA in most comparisons, particularly for the identification of F3-4/F4. In the pediatric population, imaging-based NILDA is likely as accurate as in adults. CONCLUSION: LSM from TE, SWE, and MRE show acceptable to outstanding accuracy for the detection of liver fibrosis across various liver disease etiologies. Accuracy increased from F2-4 to F3-4 and was the highest for F4. Further research is needed to better standardize the use of imaging-based NILDA, particularly in pediatric liver diseases.

Radiographic paradoxical response in metastatic castrate-resistant prostate cancer (mCRPC) managed with new generation anti-androgens: a retrospective analysis.

BACKGROUND: Prostatic specific antigen (PSA) has well-recognized limitations as a marker for treatment response and disease progression. Post hoc analysis of the PREVAIL trial reported 24.5% of chemotherapy naïve metastatic castration-resistant prostate cancer (mCRPC) patients on enzalutamide had radiographic progression on conventional imaging with nonrising PSA. In this study, we sought to study the discordance of imaging with PSA kinetics in mCRPC patients on second generation anti-androgens (SGA) post-chemotherapy using combined conventional imaging, and new generation imaging in the form of C-11 choline positron emission tomography/computed tomography (C[11] choline PET/CT) scan. METHODS: We retrospectively reviewed the medical records of 123 patients with mCRPC treated with SGA (Abiraterone or Enzalutamide) after docetaxel between 2016 and 2019. Patients underwent PSA testing, and C[11] choline PET/CT scan at baseline level before starting treatment with SGA, then every 3-6 months as part of their follow up evaluation. Loss of response to SGA was defined by increase in corrected maximum standardized uptake value (SUVmax) of pretreatment lesions on C-11 Choline PET/CT, and/or development of new lesions. Suspicious new lesions were confirmed by biopsy and/or conventional imaging. RESULTS: We identified 123 mCRPC patients who received SGA (Abiraterone, n = 106; Enzalutamide, n = 17) after docetaxel. Median duration of therapy was 13.9 months (interquartile range: 8.75-21.14). Approximately 43% (n = 53) of subjects in this study exhibited an increase in choline avidity while on SGA. Of this group, 60.4% of patients experienced a parallel rise in PSA (Group-A), whereas 39.6% displayed a paradoxical response (PR) (Group-B), defined as increased choline avidity combined with stable or down-trending PSA. Median PSA at time of increase in choline avidity was 3.1 ng/ml for Group-A, and 1.3 ng/ml for Group-B (p = 0.0176). Median SUVmax was similar in both groups (4.9 for Group-A, 4.6 for Group-B; p = 0.6072). The median time for increase in choline avidity was 9.5 versus 3.9 months for Group-A versus Group-B, respectively (Log-Rank = 0.0063). CONCLUSION: Nearly 40% of mCRPC patients placed on SGA post docetaxel chemotherapy will exhibit paradoxical responses to therapy, therefore, warranting close follow up with imaging. C-11 choline PET/CT imaging is a useful tool that can help in early predication of disease progression or treatment failure.

Prognostic role of 11C-choline PET/CT scan in patients with metastatic castrate resistant prostate cancer undergoing primary docetaxel chemotherapy.

BACKGROUND: We sought to assess the prognostic utility of 11C-choline positron emission tomography/computed tomography (PET/CT) in patients with metastatic castrate resistant prostate cancer (mCRPC) undergoing primary docetaxel chemotherapy. METHODS: We performed a single institution retrospective analysis of 77 mCRPC patients who were treated with 6 cycles of docetaxel chemotherapy, and who also underwent 11C-choline PET/CT scans at baseline (before chemotherapy), mid-course (after 3 cycles), and posttherapy (after 6 cycles). We evaluated treatment response based on percent change in blood pool-corrected maximum standardized uptake value (SUVmax) of the target lesion on PET/CT, as well as percent change in serum prostate specific antigen (PSA). Logistic regression analysis was used to identify factors associated with complete treatment response. Progression free survival (PFS) analysis was performed using log-rank test and shown on Kaplan-Meier plot. RESULTS: Percent change in blood pool-corrected SUVmax on mid-course scan was a significant predictor of complete response (odds ratio [OR]: 0.98, 95% confidence interval [CI]: 0.96-0.99, p = .0003), whereas percent change in PSA was not (OR: 0.99, 95% CI: 0.99-1.01, p = .6025). 57 of 77 patients (74%) achieved ≥20% reduction in blood pool-corrected SUVmax on mid-course; these patients were 3.6 times more likely to achieve complete response after full 6 cycles of docetaxel chemotherapy, compared to patients with <20% reduction in blood pool-corrected SUVmax (OR: 3.56, 95% CI: 1.04-16.52, p = .0420). Median PFS in the complete response group was 35.1 months (95% CI: 26.0-52.7 months), compared to 9.4 months (95% CI: 6.9-13.0 months) in the incomplete response group (p = .0005). CONCLUSIONS: Our study showed that mid-course and posttherapy 11C-choline PET/CT evaluation for mCRPC patients undergoing primary docetaxel chemotherapy can predict full course treatment response and PFS, respectively. 11C-choline PET/CT imaging may provide valuable prognostic information to guide treatment choices for patients with mCRPC.

Twitter Use by Academic Nuclear Medicine Programs: Pilot Content Analysis Study.

BACKGROUND: There is scant insight into the presence of nuclear medicine (NM) and nuclear radiology (NR) programs on social media. OBJECTIVE: Our purpose was to assess Twitter engagement by academic NM/NR programs in the United States. METHODS: We measured Twitter engagement by the academic NM/NR community, accounting for various NM/NR certification pathways. The Twitter presence of NM/NR programs at both the department and program director level was identified. Tweets by programs were cross-referenced against potential high-yield NM- or NR-related hashtags, and tabulated at a binary level. A brief survey was done to identify obstacles and benefits to Twitter use by academic NM/NR faculty. RESULTS: For 2019-2020, 88 unique programs in the United States offered NM/NR certification pathways. Of these, 52% (46/88) had Twitter accounts and 24% (21/88) had at least one post related to NM/NR. Only three radiology departments had unique Twitter accounts for the NM/molecular imaging division. Of the other 103 diagnostic radiology residency programs, only 16% (16/103) had a presence on Twitter and 5% (5/103) had tweets about NM/NR. Only 9% (8/88) of NM/NR program directors were on Twitter, and three program directors tweeted about NM/NR. The survey revealed a lack of clarity and resources around using Twitter, although respondents acknowledged the perceived value of Twitter engagement for attracting younger trainees. CONCLUSIONS: Currently, there is minimal Twitter engagement by the academic NM/NR community. The perceived value of Twitter engagement is counterbalanced by identifiable obstacles. Given radiologists' overall positive views of social media's usefulness, scant social media engagement by the NM community may represent a missed opportunity. More Twitter engagement and further research by trainees and colleagues should be encouraged, as well as the streamlined use of unique hashtags.

How We Do It: A Multidisciplinary Approach to 177Lu DOTATATE Peptide Receptor Radionuclide Therapy.

Lutetium 177 (177Lu) DOTA-0-Tyr3-Octreotate (DOTATATE) peptide receptor radionuclide therapy (PRRT) is an effective treatment for advanced gastroenteropancreatic neuroendocrine tumors. This review presents a clinical practice workflow that has been successful since 177Lu DOTATATE PRRT was approved by the U.S. Food and Drug Administration. The workflow relies heavily on the input of a multidisciplinary team and involves a nuclear medicine consultation service, tumor board, and specific preparations in advance of therapy and day-of-therapy procedures. A systematic checklist designed to ensure appropriate selection of treatment candidates and identification of any concerns to address to safely administer PRRT is provided. All patients were evaluated with gallium 68 DOTATATE PET/CT, and in cases of high-grade tumors, they were also evaluated with fluorine 18 fluorodeoxyglucose PET/CT, with imaging findings reviewed as part of the systematic checklist before PRRT. Adverse effects are discussed and imaging follow-up regimens are reviewed, including alternative diagnostic contrast materials. Approaches to multiple challenging patient scenarios are illustrated through case examples. Finally, alternative theranostic radionuclides and treatment strategies are discussed.

Catechol-Based Functionalizable Ligands for Gallium-68 Positron Emission Tomography Imaging.

Four tris-bidentate catecholamide (CAM) ligands were synthesized, characterized, and evaluated as ligands for radiolabeling of gallium-68 for positron emission tomography (PET). Three of those ligands, 2,2-Glu-CAM, 3,3-Glu-CAM, and TREN-bisGlyGlu-CAM, incorporate ligand caps that contain a pendant carboxylic group for further conjugation to targeting moieties. The acyclic ligands all exhibited high (>80%) radiolabeling yields after short reaction times (<10 min) at room temperature, a distinct advantage over macrocyclic analogues that display slower kinetics. The stabilities of the four GaIII complexes are comparable to or higher than those of other acyclic ligands used for gallium-68 PET imaging, such as desferrioxamine, with pGa values ranging from 21 to >24, although the functionalizable ligands are less stable than the parent GaIII-TREN-CAM. In vivo imaging studies and ex vivo pharmacokinetic and biodistribution studies indicate that the parent [68Ga]Ga-TREN-CAM is stable in vivo but is rapidly cleared in <15 min, probably via a renal pathway. The rapid and mild radiolabeling conditions, high radiolabeling yields, and high stability in human serum (>95%) render TREN-bisGlyGlu-CAM a promising candidate for gallium-68 chelation.

Unusual manifestations of diffuse-type tenosynovial giant cell tumor in two patients: importance of radiologic-pathologic correlation.

Diffuse-type tenosynovial giant cell tumor (TSGCT) is a rare, locally aggressive neoplasm. It most commonly occurs in the knee, followed by the hip, and has distinctive imaging features, including mass-like foci of low T2 signal intensity, "blooming" on gradient-echo MRI, and pronounced uptake on FDG PET/CT. Histologically, TSGCT demonstrates a neoplastic population of mononuclear cells admixed with hemosiderin-laden macrophages, foamy histiocytes, inflammatory cells, and osteoclast-like giant cells. In cases where diffuse-type TSGCT presents in an uncommon location or with atypical features, the imaging diagnosis may be challenging. Furthermore, because of its polymorphous appearance, it may be mistaken microscopically for other neoplastic and non-neoplastic histiocytic lesions. Herein, we present two cases of diffuse-type TSGCT presenting as large masses, and underscore the importance of radiologic-pathologic correlation for accurate diagnosis.

Stroke detection with 3 different PET tracers.

Stroke is a common cause of patient morbidity and mortality, being the fifth leading cause of death in the United States. Positron emission tomography (PET) is a proven tool for oncology patients, and may have utility in patients with stroke. We demonstrate findings of stroke incidentally detected on oncologic PET/CTs using 18F-FDG, 11C-Choline, and 68Ga-DOTATATE radiotracers. Specifically, focal 11C-Choline or 68Ga-DOTATATE uptakes localized in areas of MRI confirmed ischemia, and paradoxically increased 18F-FDG activity was visualized surrounding a region of hemorrhage, in different patients. These cases demonstrate that PET may have utility in evaluating patients with stroke based on flow dynamics, metabolic activity, and receptor expression.

Sarcoidosis with Multiorgan Involvement and Cutaneous Manifestations after Colonic Adenocarcinoma Resection.

Sarcoidosis is a systemic chronic granulomatous disease. It mostly involves the lungs and hilar lymph nodes and produces epithelioid granulomas. Granulomatous (sarcoid) reaction is known to be associated with malignancies; however, it is uncommonly seen with colon carcinomas. Furthermore, systemic sarcoidosis following cancer diagnosis is less commonly seen. To the best of our knowledge, cutaneous sarcoidosis related with an underlying colon carcinoma has not been reported previously in the literature. In this report, we present a very rare case with sarcoidosis development after resection of sigmoid adenocarcinoma, presenting with multiorgan involvement including the skin, eye, joints, and lymph nodes. 18F-fluorodeoxyglucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) images showed the skin, lung, spleen, mediastinal, and hilar lymph node involvement. Histopathological examination of skin lesions demonstrated granulomatous dermatitis. This case demonstrates that sarcoidosis can cause intensely FDG-avid lesions on 18F-FDG-PET/CT scans, mimicking metastasis in colon cancer patients. Histopathological evaluation is essential for confirming the diagnosis. 18F-FDG-PET/CT scan provides important information for evaluation of disease extension, progression, and clinical follow-up.

Therapy With 177Lu-DOTATATE: Clinical Implementation and Impact on Care of Patients With Neuroendocrine Tumors.

OBJECTIVE. The purpose of this article is to enhance knowledge of the clinical implementation of peptide receptor radionuclide therapy (PRRT) and its impact on care of patients with neuroendocrine tumors. CONCLUSION. Most well differentiated and some moderately and poorly differentiated neuroendocrine tumors express large numbers of somatostatin receptors on their cell surfaces. PRRT targets these cells with 177Lu-DOTATATE, which is a medium-energy beta emitter. Since this agent received U.S. Food and Drug Administration approval in 2018, tremendous effort has been exerted at institutions throughout the United States toward proper implementation of this promising therapy. This review summarizes clinical implementation of PRRT and its impact on patient care.

The molecular basis and genotype-phenotype correlations of congenital adrenal hyperplasia (CAH) in Anatolian population.

Congenital adrenal hyperplasia (CAH) is an autosomal recessive genetic disorder due to presence of mutations in the genes involved in the metabolism of steroid hormones in adrenal gland. There are two main forms of CAH, classic form and non-classic form. While classic form stands for the severe form, the non-classic form stands for the moderate and more frequent form of CAH. The enzyme deficiencies such as 21-hydroxylase, 11-beta-hydroxylase, 3-beta-hydroxysteroid dehydrogenase, 17-alpha-hydroxylase deficiencies are associated with CAH. In this study, we aimed to investigate CYP21A2, CYP11B1, HSD3B2 genes which are associated with 21-hydroxylase, 11-beta-hydroxylase and 3-beta-hydroxysteroid dehydrogenase enzyme deficiencies, respectively, in 365 individuals by using Sanger sequencing method. We emphasized the classification of variants according their disease causing potential, and evaluated variants' frequencies including newly discovered novel variants. As a result, 32 variants of CYP21A2 including 10 novel variants, 9 variants of CYP11B1 including 3 novel variants and 6 variants of HSD3B2 including 4 novel variants were identified. The conclusions of our study showed that in Anatolia, discovery of novel variants is quite common on account of tremendous ratios of consanguineous marriages which increases the frequency of CAH. These results will contribute to the understanding of molecular pathology of the disease.