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Background and Purpose: The impact of therapeutic embolization as a stand-alone treatment of head and neck paragangliomas considered surgically high-risk remains insufficiently understood. The aim of this study was to investigate the procedural risks and long-term volumetric development in head and neck paragangliomas with high surgical risk following therapeutic endovascular embolization as a stand-alone treatment., Materials and Methods: A retrospective database review of patients who underwent endovascular embolization as primary treatment for head and neck paragangliomas lacking appropriate curative treatment options at our institution (from January 2000 to February 2023) was conducted. Tumor volumetric analyses were performed before embolization and during follow-up. To assess the changes in tumor volume over time, the measurements were performed after embolization, first at 6 months and then on a yearly basis up to 6 years (mean follow-up time was 33.7 ± 24.4 months). Subgroup analyses were conducted for vagal and jugular/jugulotympanic paragangliomas., Results: A total of 32 head and neck paragangliomas in 28 patients (mean age, 56.1 years ± 16.5 [standard deviation]; 18 female) with therapeutic embolization as stand-alone treatment were evaluated, of which 11 were vagal paragangliomas, 15 jugular/jugulotympanic paragangliomas, and 6 carotid body tumors. After a mean follow-up duration of 33.7 ± 24.4 months, tumor control was achieved in 75%, with significant median tumor volume reduction at 6 months ( P = .02, n = 21). Vagal paragangliomas responded the most to embolization with a significantly decreased median volume from 22.32 cm 3 to 19.09 cm 3 ( P = .008, n = 8). Transient complications occurred in 3.4%., Conclusions: Therapeutic embolization as a stand-alone treatment offers a low-risk control of tumor growth in surgically high-risk lesions, with a significant reduction in tumor volume after treatment. Among the different subtypes, vagal paragangliomas exhibited the strongest and longest regression of the tumor volume., (© 2024 by American Journal of Neuroradiology.)

Hybrid PET/MRI has the potential to transform neuro-oncologic imaging, particularly in diagnosis and treatment planning of somatostatin receptor-expressing tumors of the head and neck. Hybrid PET/MRI combines high-resolution MRI with functional information from PET, providing precise anatomic information and overcoming difficulties in localization inherent to PET alone. There is a range of tumors in the head and neck that overexpress somatostatin receptors and are therefore amenable to evaluation with somatostatin receptor PET/MRI. These include meningiomas, paragangliomas, olfactory neuroblastomas, pituitary neuroendocrine tumors, middle ear neuroendocrine tumors, and medullary thyroid carcinomas. The combination of PET and MRI is superior to either modality alone and can address several unique diagnostic challenges associated with these lesions. The authors discuss the superior capabilities of somatostatin receptor PET/MRI, including improved lesion localization, more sensitive demonstration of disease extent, enhanced surveillance, optimized radiation therapy planning, and accurate prediction of response to somatostatin analog therapy. Although there are only a few dedicated PET/MRI units available in clinical practice, commercial software is now available that can automatically fuse PET/CT data with recently acquired MRI data, increasing the availability of this approach. Radiologists should be aware of the advantages of somatostatin receptor PET/MRI in evaluation of head and neck tumors as well as the potential pitfalls of this approach so that they can accurately advise clinicians and better interpret these studies. © RSNA, 2024 See the invited commentary by Shatzkes and Strauss in this issue.

Objective: To compare the diagnostic performance of [ 68 Ga]DOTATATE PET/CT, [ 18 F]FDG PET/CT, MRI of the spine, and whole-body CT and MRI for the detection of pheochromocytoma/paraganglioma (PPGL)-related spinal bone metastases., Materials and Methods: Between 2014 and 2020, PPGL participants with spinal bone metastases prospectively underwent [ 68 Ga]DOTATATE PET/CT, [ 18 F]FDG PET/CT, MRI of the cervical-thoracolumbar spine (MRI spine ), contrast-enhanced MRI of the neck and thoraco-abdominopelvic regions (MRI WB ), and contrast-enhanced CT of the neck and thoraco-abdominopelvic regions (CT WB ). Per-patient and per-lesion detection rates were calculated. Counting of spinal bone metastases was limited to a maximum of one lesion per vertebrae. A composite of all functional and anatomic imaging served as an imaging comparator. The McNemar test compared detection rates between the scans. Two-sided p values were reported., Results: Forty-three consecutive participants (mean age, 41.7 ± 15.7 years; females, 22) with MRI spine were included who also underwent [ 68 Ga]DOTATATE PET/CT (n = 43), [ 18 F]FDG PET/CT (n = 43), MRI WB (n = 24), and CT WB (n = 33). Forty-one of 43 participants were positive for spinal bone metastases, with 382 lesions on the imaging comparator. [ 68 Ga]DOTATATE PET/CT demonstrated a per-lesion detection rate of 377/382 (98.7%) which was superior compared to [ 18 F]FDG (72.0%, 275/382, p < 0.001), MRI spine (80.6%, 308/382, p < 0.001), MRI WB (55.3%, 136/246, p < 0.001), and CT WB (44.8%, 132/295, p < 0.001). The per-patient detection rate of [ 68 Ga]DOTATATE PET/CT was 41/41 (100%) which was higher compared to [ 18 F]FDG PET/CT (90.2%, 37/41, p = 0.13), MRI spine (97.6%, 40/41, p = 1.00), MRI WB (95.7%, 22/23, p = 1.00), and CT WB (81.8%, 27/33, p = 0.03)., Conclusions: [ 68 Ga]DOTATATE PET/CT should be the modality of choice in PPGL-related spinal bone metastases due to its superior detection rate., Clinical Relevance Statement: In a prospective study of 43 pheochromocytoma/paraganglioma participants with spinal bone metastases, [ 68 Ga]DOTATATE PET/CT had a superior per-lesion detection rate of 98.7% (377/382), compared to [ 18 F]FDG PET/CT (p < 0.001), MRI of the spine (p < 0.001), whole-body CT (p < 0.001), and whole-body MRI (p < 0.001)., Key Points: • Data regarding head-to-head comparison between functional and anatomic imaging modalities to detect spinal bone metastases in pheochromocytoma/paraganglioma are limited. • [ 68 Ga]DOTATATE PET/CT had a superior per-lesion detection rate of 98.7% in the detection of spinal bone metastases associated with pheochromocytoma/paraganglioma compared to other imaging modalities: [ 18 ]F-FDG PET/CT, MRI of the spine, whole-body CT, and whole-body MRI. • [ 68 Ga]DOTATATE PET/CT should be the modality of choice in the evaluation of spinal bone metastases associated with pheochromocytoma/paraganglioma., (© 2024. This is a U.S. Government work and not under copyright protection in the US; foreign copyright protection may apply.)

Objective: This study is to define a subclassification system of jugular foramen paragangliomas (JFPs) and to demonstrate corresponding microsurgical outcomes of JFPs., Study Design: Retrospective study., Setting: A single-center study., Methods: We conducted a retrospective review of the clinical data of 44 patients with JFPs who underwent surgical management. Extrabulbar(Be) tumor and intrabulbar(Bi) tumor are defined based on the growth patterns, receiver operating characteristic (ROC) curves of the imaging profile were generated and was confirmed based on intraoperative findings. Area Under Curve (AUC), accuracy, sensitivity, and specificity for diagnostic imaging were revealed. We also compared the correlation between the two growth patterns with Fisch's classification, blood loss, lower cranial nerves (LCNs) deficit., Results: There are 27 (69%) cases of Bi tumor and 17 (39%) cases of Be tumor. Significant radiomics features between the two growth patterns were demonstrated, ROC curves achieved excellent AUCs for MRI sequences (T1W1 MRI, MR contrast-enhanced sequence, MR complex sequences and MR complex + DSA by 0.833, 0.833, 0.875, 0.944) and had statistically significant in diagnosis of two growth patterns (P<0.05). There was no statistical correlation between growth patterns of JFPs and intra-operative blood loss. Preoperative LCNs deficits and Fisch's classification of tumors were correlated with the growth patterns of JFPs (P < 0.05)., Conclusion: We proposetd two growth patterns of JFPs in term of the inferior petrous sinus involvement. Identification of Bi or Be growth patterns preoperatively is helpful to design optimal surgical strategies and minimize postoperative complications., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Retroperitoneal neuroendocrine tumours are exceptionally rare. The excision of tumours located in the renal hilum near the renal vessels can be challenging. We report a case of a paraganglioma located at the renal hilum which was excised successfully in a child who presented with abdominal pain, breathlessness, left varicocele and hypertension., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Few reports have highlighted the rare presence of somatic ATRX variants in clinically aggressive, metastatic pheochromocytoma/paraganglioma (PCC/PGL); however, none have addressed detailed clinical presentation (including biochemistry and imaging) and management of these patients. Here, we address these clinical features and management based on four PCC patients with somatic ATRX variants from our National Institutes of Health PCC/PGL cohort. A total of 192 patients underwent exome sequencing (germline, somatic, or both), and four males were found to have somatic ATRX variants (with additional somatic VHL and FH oncogenic variants in patients 2 and 4, respectively). Per-lesion and per-patient comparisons were performed among functional imaging scans performed at the NIH. Biochemical phenotype and response to systemic treatment were evaluated. This mini-series supports prior studies showing aggressive/metastatic PCC in patients with somatic ATRX variants, as all developed widespread metastatic disease. All four PCC patients presented with noradrenergic biochemical phenotype, and some with significant elevation in 3-methoxytyramine. 18 F-FDOPA PET/CT was found to be the superior functional imaging modality, with 100% lesion detection rate when compared to that of 68 Ga-DOTATATE, 18 F-FDG, 18 F-FDA, and 123 I-MIBG scans. While patients did not respond to chemotherapy or tyrosine kinase inhibitors, they responded to targeted radiotherapy using high-specific-activity 131 I-MIBG (Azedra ® ) or 177 Lu-DOTATATE (Lutathera ® )., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2024 Cortez, Kuo, Jha, Patel, Carrasquillo, Prodanov, Charles, Talvacchio, Derkyi, Lin, Taïeb, Del Rivero and Pacak.)

Dopamine-secreting paragangliomas is known to be rare. The average annual incidence rate was reported 0.8 per 100,000 person-years. Approximately 1 to 2% of paragangliomas occur in the chest. We describe a patient with a large dopamine-secreting cardiac paraganglioma, right adrenal tumor and carotid body tumor. A 26-year-old man with progressive exertional dyspnea was referred to our hospital for further management of multiple paragangliomas. Positron emission tomography (PET) and PET-computed tomography (CT) detected those three legions. The diameter of cardiac paraganglioma was over 45 mm and was biggest among three tumors. Firstly, therefore, we planned cardiac paraganglioma resection. Through left lateral thoracotomy in the 4th intercostal space via, cardiac paraganglioma was resected under cardiopulmonary bypass and beating heart. Postoperative course was uneventful. Tumor cells were positive for synaptophysin and chromogranin A. Free metanephrines in the serum and urinary fractionated metanephrines normalized after cardiac surgery while the other two tumors remained untreated.

Background: The aim of this study is comparison the effectiveness of stereotactic, hypofractionated and conventional radiotherapy assessed by the tumor volume changes of paraganglioma located in the head and neck region concerning fractional and total doses., Methods: We analyzed 76 patients after radiotherapy due to paraganglioma who were assigned to 3 groups considering fractional (≤2 Gy, 3-5.5 Gy, ≥6 Gy) and total (≤20 Gy, 21-40 Gy, >40 Gy) doses. The volumes of irradiated tumors were measured and compared based on diagnostic images performed before and after the treatment., Results: The mean tumor volume after the treatment with the lowest fractional dose (≤2 Gy) was decreased by 14.4 cm 3 . In patients treated with higher fractional doses (>2 Gy), the mean tumor volumes decreased by less than 1 cm 3 for hypofractionated and stereotactic radiotherapy. 15.9 cm 3 reduction of the mean tumor volume after the treatment with the highest RT total dose (>40 Gy) was stated. In patients treated with total doses ≤20 Gy and 21-40 Gy, the mean tumor volume was stable and reduced by 1.15 cm 3 , respectively. The analysis demonstrates a statistically significant (p < 0.05) treatment advantage in patients after the lowest fractional and highest total doses., Conclusion: The reduction of the tumor's volume was reported after conventional and unconventional radiotherapy. The most significant depletion of the paraganglioma volume was noted after a factional dose ≤2 Gy and a total dose >40 Gy., (© 2024 The Author(s). Cancer Medicine published by John Wiley & Sons Ltd.)

Pheochromocytomas and Paragangliomas (PPGLs) are rare adrenal and extra-adrenal tumors that have metastatic potential. Management of patients with PPGLs mainly depends on the makeup of their genetic cluster: SDHx, VHL/EPAS1, kinase, and sporadic. CT is the preferred modality for precise localization of PPGLs, such that their metastatic progression can be assessed. However, the variable size, morphology, and appearance of these tumors in different anatomical regions can pose challenges for radiologists. Since radiologists must routinely track changes across patient visits, manual annotation of PPGLs is quite time-consuming and cumbersome to do across all axial slices in a CT volume. As such, PPGLs are only weakly annotated on axial slices by radiologists in the form of RECIST measurements. To ameliorate the manual effort spent by radiologists, we propose a method for the automated detection of PPGLs in CT via a proxy segmentation task. Weak 3D annotations (derived from 2D bounding boxes) were used to train both 2D and 3D nnUNet models to detect PPGLs via segmentation. We evaluated our approaches on an in-house dataset comprised of chest-abdomen-pelvis CTs of 255 patients with confirmed PPGLs. On a test set of 53 CT volumes, our 3D nnUNet model achieved a detection precision of 70% and sensitivity of 64.1%, and outperformed the 2D model that obtained a precision of 52.7% and sensitivity of 27.5% (p< 0.05). SDHx and sporadic genetic clusters achieved the highest precisions of 73.1% and 72.7% respectively. Our state-of-the art findings highlight the promising nature of the challenging task of automated PPGL detection., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Published by Elsevier Ltd.)

Objective: The objective of this study was to evaluate the clinical effect and safety of the postauricular infratemporal fossa approach (ITFA) in resecting jugular foramen lesions., Methods: All 25 patients undergoing microsurgery via postauricular ITFA from March 2015 to May 2023 in the Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University were included. The clinical and radiological data were retrospectively analyzed. Regular follow-up was carried out., Results: The mean age of all patients was 50.5±8.9 years, and 14 of them were female and 11 were male. Among the cases, lower cranial nerve schwannoma accounted for 60 % (15/25) of all tumors, jugular foramen paraganglioma accounted for 20 % (5/25), and the remaining 20 % included meningioma, chondrosarcoma, plasmacytoma, and salivary gland tumors. Total tumor resection was performed in 18 cases, subtotal tumor resection in 7 cases and partial resection in 1 case. Seven patients underwent gamma knife radiotherapy after surgery. Transient lower cranial nerve dysfunction occurred in 8 patients, and permanent lower cranial nerve dysfunction occurred in 2 patients after surgery. One patient developed facial paralysis, and one patient presented hearing loss., Conclusions: The postauricular ITFA achieved a relatively high total tumor resection rate and a lower incidence of neurological functional disorders. It is an alternative and suitable surgical approach for resecting jugular foramen lesions. Maximizing the preservation of neurological function is preferred, especially when radical resection cannot be achieved. Stereotactic radiotherapy could be used for residual tumors., Competing Interests: Declaratio of Competing Interest The authors have no conflicts of interest regarding the data used in this study., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Abstract: We present the imaging findings of a 48-year-old woman that metastasized to multiple bones with a history of duodenal gangliocytic paraganglioma. 68Ga-DOTATATE PET/CT showed multiple osteolytic bone destruction with intense uptake. Multiple bone metastases originating from duodenal gangliocytic paraganglioma confirmed histopathological results of a biopsy on the chest-back bone., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Paragangliomas (PGLs) are rare and encapsulated neuroendocrine tumors (NET), located in the adrenal gland or the extra-adrenal paraganglia. Extra-adrenal PGLs may develop a gangliocytic component with ganglion cells which are called gangliocytic paragangliomas (GPs). The most common location is the duodenum, and they appear with digestive symptoms or as an incidental finding. We described a 43 years old patient, with epigastric pain, nausea and vomiting. The CT-scan reveals a nodular image in the duodenum. An ultrasound-guided FNA was performed and the pathological report revealed neuroendocrine cell groups and neural tissue. Surgery was the chosen treatment. As the patient did not present lymphatic or pancreatic parenchyma invasion, radiotherapy (RT) was not administered. The management of GPs is not well established and multidisciplinary team approach is recommended to lead to therapeutic options. Surgical resection is still key in the treatment, and adjuvant RT may be considered in cases of lymph node invasion., (Copyright © 2024 SEEN and SED. Published by Elsevier España, S.L.U. All rights reserved.)

Rationale and Objectives: Using different machine learning models CT-based radiomics to integrate clinical radiological features to discriminating the risk stratification of pheochromocytoma/paragangliomas (PPGLs)., Materials and Methods: The present study included 201 patients with PPGLs from three hospitals (training set: n = 125; external validation set: n = 45; external test set: n = 31). Patients were divided into low-risk and high-risk groups using a staging system for adrenal pheochromocytoma and paraganglioma (GAPP). We extracted and selected CT radiomics features, and built radiomics models using support vector machines (SVM), k-nearest neighbors, random forests, and multilayer perceptrons. Using receiver operating characteristic curve analysis to select the optimal radiomics model, a combined model was built using the output of the optimal radiomics model and clinical radiological features, and its accuracy and clinical applicability were evaluated using calibration curves and clinical decision curve analysis (DCA)., Results: Finally, 13 radiomics features were selected to construct machine learning models. In the radiomics model, the SVM model demonstrated higher accuracy and stability, with an AUC value of 0.915 in the training set, 0.846 in external validation set, and 0.857 in external test set. Combining the outputs of SVM models with two clinical radiological features, a combined model constructed has demonstrated optimal risk stratification ability for PPGLs with an AUC of 0.926 for the training set, 0.883 for the external validation set, and 0.899 for the external test set. The calibration curve and DCA show good calibration accuracy and clinical effectiveness for the combined model., Conclusion: Combined model that integrates radiomics and clinical radiological features can discriminate the risk stratification of PPGLs., Competing Interests: Competing Interests The authors declare that they have no competing interests., (Copyright © 2024 The Association of University Radiologists. Published by Elsevier Inc. All rights reserved.)

The resection of middle ear paragangliomas can be challenging given their vascular nature and the small volume of the tympanic cavity, particularly when the tumor in the hypotympanum is close or attached to the internal carotid artery (ICA). We performed combined underwater endoscopic and microscopic surgery for a Class B1 middle ear paraganglioma according to the modified Fisch classification. The suspicious bone in the hypotympanum and around the petrous ICA was drilled with underwater endoscopy. The feeding arteries, the caroticotympanic and inferior tympanic arteries, were suctioned and cauterized under microscopy. To the best of our knowledge, no case of middle ear paraganglioma treated with underwater endoscopy has been reported. Underwater endoscopy, providing a clear operative field with blood and bone dust irrigation, is a good indication for middle ear paragangliomas. In contrast, microscopic preparation for unexpected bleeding is important, particularly when the tumor closely extends to vital structures, such as the ICA or the jugular bulb., Competing Interests: Declaration of conflicting interestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Purpose: To investigate the [ 68 Ga]DOTATOC PET radiomic profile of head and neck paragangliomas (HNPGLs) and identify radiomic characteristics useful as predictors of succinate dehydrogenase genes (SDHx) pathogenic variants., Methods: Sporadic and SDHx HNPGL patients, who underwent [ 68 Ga]DOTATOC PET/CT, were retrospectively included. HNPGLs were analyzed using LIFEx software, and extracted features were harmonized to correct for batch effects and confronted testing for multiple comparison. Stepwise discriminant analysis was conducted to remove redundancy and identify best discriminating features. ROC analysis was used to define optimal cut-offs. Multivariate decision-tree analysis was performed using CHAID method., Results: 34 patients harboring 60 HNPGLs (51 SDHx in 25 patients) were included. Three sporadic and nine SDHx HNPGLs were metastatic. At stepwise discriminant analysis, both GLSZM-Zone Size Non-Uniformity (ZSNU, reflecting tumor heterogeneity) and IB-TLSRE (total lesion somatostatin receptor expression) were independent predictors of genetic status, with 96.4% of lesions and 91.6% of patients correctly classified after cross validation (p < 0.001). Among non-metastatic patients, GLSZM-ZSNU and IB-TLSRE were significantly higher in sporadic than SDHx HNPGLs (p < 0.001). No differences were revealed in metastatic patients. Decision-tree analysis highlights multifocality and IB-TLSRE as useful variables, correctly identifying 6/9 sporadic and 24/25 SDHx patients. Model failed to classify one SDHA and three sporadic patients (2 metastatic)., Conclusion: Radiomics features GLSZM-ZSNU and IB-TLSRE appear to reflect HNPGLs SDHx status and tumor behavior (metastatic vs. non-metastatic). If validated, especially IB-TLSRE might represent a simple and time-efficient radiomic index for SDHx variants early screening and prediction of tumor behavior in HNPGL cases., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Patients and Methods: The primary endpoints were objective response rate (ORR) and disease control rate (DCR). Secondary endpoints were duration of response, blood pressure control, safety, overall and progression-free survival rates, MIBG uptake, and correlations with genetic background., Results: The study included 25 patients. Twenty-four patients had distant metastases, 17 (68%) had hormonally active tumors, and 13 (52%) had previously received antineoplastic treatment. In 24 evaluable patients, the ORR was 38%, including 2 patients with complete response, and the DCR was 83%; median time to response was 12.5 months (95% confidence interval, 4.6-25.1). Twelve patients had sporadic disease, among whom the ORR was 25% and DCR was 83%. Twelve patients had hereditary disease ( SDHB , VHL , RET ); among these, the ORR was 50%, and DCR was 83%. Plasma metanephrines normalized in 30% of patients and improved by greater than 50% in 46%. Sixteen patients had hormonally active tumors and hypertension; in 9 (56%) of these, blood pressure normalized, leading to discontinuation of antihypertensive therapy.The most common adverse events were grades 1-2 nausea/vomiting and transient bone marrow suppression. One patient developed premature ovarian failure. Reversible grades 3-4 myelosuppression were seen in 7 patients (28%). One patient had fatal pneumonitis., Conclusions: HSA- 131 I-MIBG is associated with a high DCR in patients with MPPGL, regardless of underlying genetic mutation., Competing Interests: Conflicts of interest and sources of funding: YL has received research support from Lantheus Pharmaceuticals. CJ has received research support from Progenics/Lantheus Pharmaceuticals, Exelixis, and MSD. RAW, VBB, SS, CLP, GX, SGW, JV, and MAH do not have disclosures., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Introduction: Preclinical and animal studies have suggested that excess catecholamines can lead to bone mineral loss. However, to date, no systematic review is available that has analyzed the impact of catecholamine excess in the context of pheochromocytoma/paraganglioma (PPGL) on bone metabolism. We conducted this meta-analysis to address this knowledge gap., Methods: Electronic databases were searched for studies evaluating bone metabolism, including assessments of bone mineral density (BMD), quantitative computed tomography (qCT), trabecular bone score (TBS), or bone turnover markers in patients with PPGL. These markers included those of bone resorption, such as tartrate-resistant acid phosphatase 5b (TRACP-5b) and cross-linked C-telopeptide of type I collagen (CTx), as well as markers of bone formation, such as bone-specific alkaline phosphatase (BS ALP)., Results: Out of the initially screened 1614 articles, data from six studies published in four different patient cohorts with PPGL that met all criteria were analysed. Individuals with PPGL had significantly lower TBS [Mean Difference (MD) -0.04 (95% CI: -0.05--0.03); p < 0.00001; I2 = 0%], higher serum CTx [MD 0.13 ng/ml (95% CI: 0.08-0.17); p < 0.00001; I2 = 0%], and higher BS-ALP [MD 1.47 U/L (95% CI: 0.30-2.64); p = 0.01; I2 = 1%]. TBS at 4-7 months post-surgery was significantly higher compared to baseline [MD 0.05 (95% CI: 0.02-0.07); p < 0.0001]. A decrease in CTx has been documented post-surgery., Conclusion: Bone health deterioration is a major concern in patients with PPGL. In addition to providing a definitive cure for catecholamine excess, monitoring and treating osteoporosis is essential for individuals with secondary osteoporosis due to PPGL. Long-term studies on bone health outcomes in PPGL are warranted., Competing Interests: Declaration of competing interest The authors declare there is no conflict of interests., (Copyright © 2024 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.)

This continuing education aims to present in a clear and easy-to-understand manner the biology of paragangliomas and pheochromocytomas (PPGLs), the functional imaging studies available for their diagnosis and therapeutic planning, the requirements necessary to administer radioligand therapy (RLT) and the characteristics of these treatments (inclusion criteria, administration protocols, adverse effects and future perspectives). In this pathology we have two RLT options: [ 131 I]MIBG and [ 177 Lu]Lu-DOTA-TATE. The indication for treatment is determined by the expression of its therapeutic target in functional imaging studies, allowing precision and personalized medicine. Although most of the results we have for both treatments have as origin small retrospective series, RLT is presented as a safe and well-tolerated therapeutic option in PPGLs with slow-moderate progression or with uncontrollable symptoms, obtaining high disease control rates., (Copyright © 2024 Sociedad Española de Medicina Nuclear e Imagen Molecular. Published by Elsevier España, S.L.U. All rights reserved.)

Background: Hypertension (HT) is one of the most common manifestations in patients with catecholamine-secreting neuroendocrine tumors. Although the cardiovascular manifestations of these tumors have been described, there have been no large-scale investigations of the profile of HT and changes in cardiac structure and function that occur in patients with pheochromocytomas and paragangliomas (PPGL)., Materials and Methods: In this study, we investigated the prevalence of HT and left ventricular remodeling (LVR) in a cohort of 598 patients who underwent surgery for PPGL at our center between January 2001 and April 2022. Information on demographics, reason for hospitalization, medical history, biochemical parameters, findings on echocardiography, and tumor characteristics were recorded. The LVR index was compared according to whether or not there was a history of HT., Results: The average age was 47.07 ± 15.07 years, and 277 (46.32%) of the patients were male. A history of HT was found in 423 (70.74%) of the 598 patients. Paraganglioma was significantly more common in the group with HT (26.00% vs. 17.71%, P = 0.030) and significantly less likely to be found incidentally during a health check-up in this group (22.93% vs. 59.43%, P < 0.001). Among 365 patients with complete echocardiography data, left ventricular mass index (86.58 ± 26.70 vs. 75.80 ± 17.26, P < 0.001) and relative wall thickness (0.43 ± 0. 08 vs. 0.41 ± 0.06, P = 0.012) were significantly higher in patients with PPGL and a history of HT. The proportions with left ventricular hypertrophy (LVH) (19.40% vs. 8.25%, P = 0.011) and LVR (53.73% vs. 39.18%, P = 0.014) were also higher when there was a history of HT. After adjusting for age, gender, body mass index, alcohol consumption, smoking status, diabetes, stroke, creatinine level, tumor location, and tumor size, a history of HT was significantly correlated with LVH (odds ratio 2.71, 95% confidence interval 1.18-6.19; P = 0.018) and LVR (odds ratio 1.83, 95% confidence interval 1.11-3.03; P = 0.018)., Conclusion: HT is common in patients with PPGL (70.74% in this cohort). PPGL without a history of HT is more likely to be found incidentally (59.43% in our cohort). HT is associated with LVR in PPGL patients with complete echocardiography data. These patients should be observed carefully for cardiac damage, especially those with a history of HT., (© 2024. The Author(s).)

This study aimed to compare tumor lesion detectability and diagnostic accuracy of whole-body magnetic resonance imaging (WB-MRI) and radioiodine-labeled meta-iodo-benzylguanidine (mIBG) imaging techniques in patients with metastatic pheochromocytoma and paraganglioma (PPGL). This retrospective study included 13 patients had pheochromocytoma and 5 had paraganglioma, who were all suspected of having metastatic tumors. Each patient underwent WB-MRI and 123 I-mIBG as a pretreatment screening for 131 I-mIBG therapy. Two expert reviewers evaluated WB-MRI, 123 I-mIBG images, and post-therapy 131 I-mIBG images for the presence of metastatic lesions in the lungs, bones, liver, lymph nodes, and other organs. Diagnostic measures for detecting metastatic lesions, including sensitivity, specificity, accuracy, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristics (ROC)-area under the curve (AUC), were calculated for each imaging technique. We analyzed WB-MRI images for detecting metastatic lesions, which demonstrated sensitivity, specificity, accuracy, PPV, NPV, and AUC of 82%, 97%, 90%, 96%, 86%, and 0.92, respectively. These values were 83%, 95%, 89%, 94%, 86%, and 0.90 in 123 I-mIBG images and 85%, 92%, 89%, 91%, 87%, and 0.91 in post-therapy 131 I-mIBG images, respectively. Our results reveal the comparable diagnostic accuracy of WB-MRI to one of the mIBG images., (© 2024. The Author(s).)

Background: This paper reports the first case of basaloid squamous cell carcinoma clinically and radiologically masquerading as a head and neck paraganglioma., Case Presentation: A 66-year-old Sinhalese male with unilateral hearing impairment and 7th-12th (excluding 11th) cranial nerve palsies was diagnosed radiologically with a head and neck paraganglioma by magnetic resonance imaging of the brain, which revealed a hypointense and hyperintense punctate mass centered at the jugular fossa with intracranial extension. The ascending pharyngeal artery, recognized as the major feeder, was embolized by percutaneous embolization following digital subtraction angiography. Gross total resection of the tumor was followed by an uneventful postoperative recovery. Combined immunohistochemistry and histopathological morphology revealed a basaloid squamous cell carcinoma, following which the patient completed radiotherapy and is at 3-month follow-up currently., Conclusion: This case report discusses the diagnostic pitfalls and management challenges of this rare entity on the basis of prior evidence, as well as a literature review and clinical and surgical analysis., (© 2024. The Author(s).)

Purpose: To compare the detection ability of 68 Ga-labelled DOTA-l-Nal3-octreotide ([ 68 Ga]Ga-DOTA-NOC) and 6-[ 18 F]fluoro-L-3,4-dihydroxyphenylalanine ([ 18 F]DOPA) in patients with phaeochromocytomas and paragangliomas (PPGLs) of different origins and gene mutations, such as germline succinate dehydrogenase complex genes (SDHx)., Methods: Eighty-five patients with histopathologically confirmed PPGLs who underwent both [ 68 Ga]Ga-DOTA-NOC and [ 18 F]DOPA PET/CT from March 2017 to June 2023 were enrolled in this retrospective study. For comparative analyses, PPGLs were classified as phaeochromocytoma (PCC), sympathetic paraganglioma (sPGL), and head/neck paraganglioma (HNPGL). Detection rates were analyzed on per-patient and per-lesion bases and compared using the Chi-square/Fischer's exact test., Results: Among 85 patients with PPGLs (48 males; 43 years ± 17 [SD]), the patient-based detection rates of [ 68 Ga]Ga-DOTA-NOC and [ 18 F]DOPA PET/CT were 87.1% (74/85) and 89.4% (76/85), respectively (p = 0.634), and the lesion-based detection rates were 80.8% (479/593) and 71.2% (422/593), respectively (p < 0.001). Only one patient with a recurrent PCC presented double-negative imaging, while 66 patients exhibited double-positive imaging. The remaining patients were either [ 68 Ga]Ga-DOTA-NOC-negative/[ 18 F]DOPA-positive (n = 10) or [ 68 Ga]Ga-DOTA-NOC-positive/[ 18 F]DOPA-negative (n = 8). In subgroup analyses, [ 68 Ga]Ga-DOTA-NOC PET/CT detected significantly more metastases of sPGL (91.1%, 236/259) and SDHx-related PPGL (89.6%, 86/96) than [ 18 F]DOPA PET/CT (48.6%[126/259] and 50.0%[48/96], respectively; both p < 0.001). However, [ 18 F]DOPA showed significantly higher detection rates of PCC in both primary/recurrent and metastatic lesions (94.3%[50/53] vs. 62.3%[33/53] and 87.9%[174/198] vs. 69.2%[137/198], respectively; both p < 0.001). Regarding metastases in different organs, [ 68 Ga]Ga-DOTA-NOC PET/CT detected more lesions than [ 18 F]DOPA PET/CT in bone (96.2%[176/183] vs. 66.1%[121/183]; p < 0.001) and lymph nodes (82.0%[73/89] vs. 53.9%[48/89]; p < 0.001) but less lesions in peritoneum (20%[4/20] vs. 100%[20/20]; p < 0.001)., Conclusion: [ 68 Ga]Ga-DOTA-NOC and [ 18 F]DOPA are complementary in diagnosing PPGL under the appropriate clinical setting. [ 68 Ga]Ga-DOTA-NOC should be considered as the ideal first-line tracer for detecting metastases of sPGL and SDHx-related tumours, whereas [ 18 F]DOPA may be the optimal tracer for evaluating non-SDHx-related PCC, especially in detecting primary lesions and monitoring recurrence., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Objective: To report our initial clinical experience with N-hexyl cyanoacrylate (NHCA), a novel liquid agent for neurovascular embolization., Methods: Four paragangliomas were treated with percutaneous embolization using NHCA as the sole embolic material. In one dural arteriovenous fistula (dAVF), NHCA was used in combination with other embolic materials. Procedural specifics, complications and angiographic results were retrospectively evaluated., Results: Total or subtotal devascularization was obtained in 3 of the 4 paragangliomas. In the largest tumor, only partial devascularization could be achieved. The dAVF was completely occluded. Catheter entrapment did not occur. After dAVF treatment, the patient had an asymptomatic lacunar infarction, while there was no procedural morbidity related to paraganglioma treatment., Conclusions: In this series, neurovascular embolization with NHCA was feasible and effective. It may be particularly beneficial for small and tortuous vessels that require low-profile catheterization and a slow and controlled polymerization. Further studies are necessary to prove the benefits of NHCA over established embolic agents., Competing Interests: Declaration of conflicting interestsThe author(s) declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Xxxxxxx.CK serves as consultant for Acandis GmbH (Pforzheim, Germany) and as proctor for MicroVention Inc./Sequent Medical (Aliso Viejo, CA, USA), and for CERUS Endovascular (Fremont, CA, USA). The other authors declare that they have no competing interests.

Introduction: Tympanojugular paragangliomas (TJ PGLs) are rare tumors characterized by bone infiltration and erosion and a close relationship with critical structures, such as cranial nerves and internal carotid artery. For these reasons, their management represents a tough challenge. Since the fifties, radio-therapy (RT) has been proposed as an alternative treatment aimed at avoiding tumor progression. However, the indolent nature of the tumor, characterized by slow growth, is a crucial factor that needs to be considered before offering radiation., Methods: This study aims to examine tumor progression in RT patients through a systematic review of the literature and in TJ PGL patients who underwent solely wait and scan at our department., Results: The rate of tumor progression in the RT group was 8.9%, while in the wait and scan cohort was 12.9%. This data suggests the innate slow growth of PGLs. However, it is not possible to draw certain conclusions because of the wide heterogeneity of the studies., Conclusion: When complete surgical excision of TJ PGLs is not feasible, appropriate counseling and patient selection, including comprehensive tumor classification, should be performed before proposing RT to control tumor progression, since wait and scan may represent a reasonable option in selected cases., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Purpose: This retrospective study aimed to assess the safety and technical efficacy of preoperative direct puncture embolization using a nonadhesive ethylene vinyl alcohol (EVOH) copolymer-based liquid embolic agent (LEA) combined with balloon occlusion at the origin of the external carotid artery for head and neck paragangliomas (HNP)., Methods: We conducted a review of all consecutive cases of HNPs treated with direct puncture embolization using EVOH-based LEAs between 2017 and 2022 in 2 tertiary high-volume hospitals., Results: A total of 25 cases of HNPs in 24 patients underwent direct puncture embolization (12 males, 12 females, mean age 50.9 ± 15.6 years). The average lesion volume was 299.95 mm 3 . The mean procedure time was 139.11 min, and the mean volume of EVOHs used per case was 19.38 mL. Successful complete devascularization was achieved in all cases, with a homogeneous and deep penetration of the embolic agent into the tumor vessel bed regardless of the LEA type., Conclusion: Preoperative embolization of HNPs using a direct puncture technique and EVOHs is a safe, efficient, and feasible treatment option with a low risk of complications. This procedure facilitates surgery by transforming tumors into avascular masses that are well-delineated against the surrounding normal tissue., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany.)

Background: Pheochromocytoma, or paraganglioma (PPGL), is a tumor that arises from catecholamine-producing chromaffin cells of the adrenal medulla or paraganglion. Systemic therapy, such as the combination of cyclophosphamide, vincristine, and dacarbazine or therapeutic radiopharmaceuticals such as [131I] meta-iodobenzylguanidine (MIBG), may be administered in cases of locally advanced tumors or distant metastases. However, the current therapies are limited in terms of efficacy and implementation. [211At] meta-astatobenzylguanidine (MABG) is an alpha-emitting radionuclide-labeled ligand that has demonstrated remarkable tumor-reducing effects in preclinical studies, and is expected to have a high therapeutic effect on pheochromocytoma cells., Methods: We are currently conducting an investigator-initiated first-in-human clinical trial to evaluate the pharmacokinetics, safety, and efficacy of [211At] MABG. Patients with locally unresectable or metastatic PPGL refractory to standard therapy and scintigraphically positive [123I] MIBG aggregation are being recruited, and a 3 + 3 dose escalation design was adopted. The initial dose of [211At] MABG is 0.65 MBq/kg, with a dose escalation in a 1:2:4 ratio in each cohort. Dose-limiting toxicity is observed for 6 weeks after a single bolus dose of [211At] MABG, and the patients are observed for 3 months to explore safety and efficacy profiles. The primary endpoint is dose-limiting toxicity to determine both maximum tolerated and recommended doses. The secondary endpoints include radiopharmacokinetics, urinary radioactive excretion rate, urinary catecholamine response rate, objective response rate, progression free survival, [123I] MIBG scintigraphy on reducing tumor accumulation, and quality of life., Trials Registration: jRCT2021220012 registered on 17 June 2022., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Kobayakawa et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Pheochromocytomas/paragangliomas are unique in their highly variable molecular landscape driven by genetic alterations, either germline or somatic. These mutations translate into different clusters with distinct tumor locations, biochemical/metabolomic features, tumor cell characteristics (eg, receptors, transporters), and disease course. Such tumor heterogeneity calls for different imaging strategies in order to provide proper diagnosis and follow-up. This also warrants selection of the most appropriate and locally available imaging modalities tailored to an individual patient based on consideration of many relevant factors including age, (anticipated) tumor location(s), size, and multifocality, underlying genotype, biochemical phenotype, chance of metastases, as well as the patient's personal preference and treatment goals. Anatomical imaging using computed tomography and magnetic resonance imaging and functional imaging using positron emission tomography and single photon emission computed tomography are currently a cornerstone in the evaluation of patients with pheochromocytomas/paragangliomas. In modern nuclear medicine practice, a multitude of radionuclides with relevance to diagnostic work-up and treatment planning (theranostics) is available, including radiolabeled metaiodobenzylguanidine, fluorodeoxyglucose, fluorodihydroxyphenylalanine, and somatostatin analogues. This review amalgamates up-to-date imaging guidelines, expert opinions, and recent discoveries. Based on the rich toolbox for anatomical and functional imaging that is currently available, we aim to define a customized approach in patients with (suspected) pheochromocytomas/paragangliomas from a practical clinical perspective. We provide imaging algorithms for different starting points for initial diagnostic work-up and course of the disease, including adrenal incidentaloma, established biochemical diagnosis, postsurgical follow-up, tumor screening in pathogenic variant carriers, staging and restaging of metastatic disease, theranostics, and response monitoring., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society.)

Purpose: We sought to summarize the value of contrast-enhanced computed tomography (CECT) in the differential diagnosis of bladder paraganglioma (BPG) and bladder cancer., Methods: The medical records of 19 patients with BPG (13 males, 6 females) and 56 patients with bladder cancer (49 males, 7 females) between November 2007 and June 2023 were retrospectively reviewed. All patients underwent unenhanced and contrast-enhanced CT scanning., Results: Patient age (46.4 ± 11.1 years vs. 58.6 ± 16.0 years), tumor calcification (1/19 vs. 18/56), stalk (0/19 vs. 10/56), internal vessels (15/19 vs. 19/56) and the enlarged adjacent supplying artery (14/19 vs. 10/56) were significantly different between BPG and bladder cancer (P < 0.05). The CT value in the corticomedullary phase (92.4 ± 16.6 HU vs. 64.0 ± 14.5 HU) and the contrast-enhanced value in the corticomedullary phase (54.5 ± 17.4 HU vs. 28.5 ± 12.8 HU) were significantly greater in BPG patients than in bladder cancer patients (P < 0.001), with corresponding area under the curve values of 0.930 and 0.912, respectively. The optimal cutoff values were 83.2 HU and 38.5 HU, respectively. A CT value > 83.2 HU in the corticomedullary phase and a contrast-enhanced CT value > 38.5 HU in the corticomedullary phase were used to indicate BPG with sensitivities of 78.9% and 89.5%, respectively, and specificities of 94.6% and 75.0%, respectively., Conclusion: The corticomedullary phase of CECT plays an important role in the preoperative differential diagnosis of BPG and bladder cancer., (© 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Background and Objectives: Paragangliomas (PGLs) are rare neuroendocrine extra-adrenal tumors that could be secreting mass. The symptoms are the typical triad of paroxysmal headache, hypertension and sweating, but could also be accompanied by symptoms involving multiple organs. Surgery is the gold standard treatment for both PGLs and pheochromocytomas (PHEOs). Material and Methods: We used a computerized endocrine surgery registry to record the demographic and clinical data of 153 patients who underwent surgery for PPGL between 2010 and 2023 at our hospital. Results: Thirteen patients (8.43%) with paragangliomas underwent surgery at our institute. Five patients presented symptomatic syndrome. Preoperative investigations included enhanced abdominal CT (nine patients) and enhanced MRI (seven patients). In cases of suspicious mass, we performed 131I-MIBG scans (two patients) or 68GA-DOTATOC PET-CT scans (11 patients). Laparoscopic approach was used in four cases (30.7%) and abdominal laparotomy in the other nine (69.3%). Biochemical tests were performed on all patients. Conclusions: In this retrospective study, we discuss the multidisciplinary management in our institute of this rare disease, from its challenging diagnosis to the surgical strategy for PGLs. Laparoscopic surgery is the gold standard, but a tailored approach should be adopted for each patient.

Here, we report a case of a woman in her 50s who was referred for an incidentally discovered lesion anterior to the origin of inferior vena cava suspicious for a paraganglioma following a CT scan for vaginal bleeding. A follow-up 68 Ga-DOTATATE PET-CT and MRI of the abdomen reinforced the radiological impression of an extra-adrenal paraganglioma (EAP). The EAP was deemed non-functional given normal urine biogenic amine, supine plasma fractionated metanephrines and chromogranin A levels. The mass was resected laparoscopically without perioperative blockade. Histological examination revealed a venous malformation. Extrahepatic abdominal venous malformations are rare and can be indistinguishable from an EAP on imaging preoperatively. Although benign, the lesion nevertheless warrants excision as it is associated with a risk of haemorrhage., Competing Interests: Competing interests: None declared., (© BMJ Publishing Group Limited 2024. No commercial re-use. See rights and permissions. Published by BMJ.)

Abstract: Primary pulmonary paragangliomas are rare neuroendocrine tumors and are often discovered incidentally as nonfunctioning masses. We report a case of 58-year-old woman recently diagnosed with multifocal right breast cancer and suspicious right axillary lymph nodes. 18 F-FDG PET/CT showed a well-defined marginated lesion in the lower lobe of the right lung with intense FDG uptake. Findings were suspicious for pulmonary metastases. CT-guided biopsy results were consistent with a paraganglioma. Paragangliomas can mimic metastases, especially if they are large or have a high degree of FDG uptake, and careful evaluation of imaging features and clinical findings can help differentiate these entities. Most of the time biopsy is necessary to confirm the diagnosis., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Cauda Equina Neuroendocrine Tumors (CE-NET), previously referred to as paragangliomas are a rare subset of spinal tumors, with limited data on imaging. Herein, we present a retrospective review of clinical and imaging findings of CE-NETs in ten patients who were evaluated at our institution over the past two decades. All patients had well-defined intradural lesions in the lumbar spine which demonstrated slow growth. A review of imaging findings revealed the presence of an eccentric vascular pedicle along the dorsal aspect of the tumor in 8 of the 10 patients (eccentric vessel sign), a distinctive finding that has not previously been reported with this tumor and may help improve the accuracy of imaging-based diagnosis. In all cases, a gross-total resection was performed, with resolution of symptoms in most of the cases., Competing Interests: Declaration of conflicting interestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Background: Head and Neck Paragangliomas are characterized by having a rich blood supply. Presurgical embolization with Onyx as a neoadjuvant treatment is not a consensus regarding its efficacy and safety. Our study aimed to answer this matter through a single-arm meta-analysis., Methods: We systematically reviewed 4 databases. Sixteen studies were described and suitable papers were selected for meta-analysis of estimated intraoperative blood loss (EBL), percentage of tumor devascularization, and complications associated with embolization., Results: The study identified 198 patients with 203 tumors, aged between 8 and 70 years. Commonly reported symptoms included neck mass perception and cranial nerve impairment. Carotid Body Tumors were most prevalent (127, 62.5 %), followed by jugular (48, 23.6 %), or vagal (29, 14.2 %) tumors. Eight studies reported estimated intraoperative blood loss (EBL) averaging 261.89 ml (95 %CI: 128.96 to 394.81 ml). In an analysis of 9 studies, 99 % (95 %CI: 96 to 100 %) achieved 70 % or more devascularization, and 79 % (95 %CI: 58 to 100 %) achieved 90 % or more devascularization. Complications from endovascular procedures were observed in 3 % (95 %CI: 0 to 8 %) of 96 patients across 10 studies, including 4 facial nerve deficits. Eighteen postoperative neurological deficits were reported across 15 articles., Conclusion: Despite acknowledged limitations, with refined indications, EVOH, especially Onyx embolization may significantly bolster patient safety, decreasing EBL and easing surgical resection. Further research with larger studies will refine criteria, optimize techniques, and improve patient care and treatment outcomes in the management of head and neck paragangliomas., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Introduction: Pheochromocytomas and paragangliomas (PPGLs) are rare neuroendocrine tumours that produce catecholamines. [131I] metaiodobenzylguanidine (MIBG)-avid unresectable or metastatic PPGLs are treated with [131I] MIBG radionuclide therapy. A high metabolic tumour volume (MTV) and total lesion glycolysis (TLG) can be poor prognostic factors. Therefore, we evaluated the metabolic responses to [131I] MIBG therapy with respect to other clinical factors., Methods: A retrospective study was performed on a series of 20 patients who underwent FDG-PET before and after [131I] MIBG therapy. We administered a single dose comprising 5.5 GBq of [131I] MIBG (usually three times; for some cases, the number was increased or decreased considering treatment efficacy and side effects). Semi-quantitative parameters (SUVmax, MTV, and TLG) were calculated using the liver SUV (mean + 3 × standard deviation) as a threshold on Metavol software. The semi-quantitative FDG-PET parameters for determining response were complete response (CR), partial remission (PR), stable disease (SD), and progressive disease (PD). We divided our study participants into the PD and non-PD groups (i.e., SD + PR + CR) and compared the overall survival (OS) between the two groups. Subsequently, we evaluated the relationships between metabolic response and age, sex, tumour type, metastatic site, chemotherapy or external radiation history, and 24-h urine catecholamine levels by univariate logistic regression analyses., Results: Both MTV-based and TLG-based criteria for PD versus non-PD were significant prognostic factors (p = 0.014). However, treatment response as evaluated based on the SUVmax was not a significant predictor. Higher urinary dopamine levels were associated with poor metabolic response as assessed by MTV and TLG (OR 1.002, p = 0.029). The other clinical parameters were non-significant., Conclusion: Poor metabolic response (measured with MTV and TLG) to [131I] MIBG therapy in unresectable or metastatic PPGLs was related to shorter OS. The poor metabolic response can be predicted using the urinary dopamine level., (© 2023 The Author(s). Published by S. Karger AG, Basel.)

Vagal paragangliomas (VPs) are rare tumors arising from paraganglionic tissue within the vagal nerve's perineurium. Usually, benign vascular tumors, VPs tend to invade the surrounding structures. Herein, we report the case of a VP presenting as a neck mass, which was evaluated as a glomus caroticum tumor preoperatively. A 65-year-old female complaining of a left-sided neck mass and intermittent hoarseness was assessed and operated on for possible glomus caroticum tumor. During the tumor excision, the vagal nerve was also involved, and hence, sacrificed. Histopathological examination revealed an encapsulated tumor associated with a nerve and ganglion and immunohistochemical staining tested positive for succinate dehydrogenase, confirming the diagnosis of VP. Postoperative residual hoarseness was corrected by vocal rehabilitation. While evaluating a retropharyngeal prestyloid neck mass, a VP should always be considered. Surgical excision involving vagal scarification, followed by vocal rehabilitation may be the appropriate treatment strategy.

Aim: The differentiation of paragangliomas, schwannomas, meningiomas, and other neuroaxis tumors in the head and neck remains difficult when conventional MRI is inconclusive. This study assesses the utility of 68 Ga-DOTATATE PET/CT as an adjunct to hone the diagnosis., Patients and Methods: This retrospective study considered 70 neuroaxis lesions in 52 patients with 68 Ga-DOTATATE PET/CT examinations; 22 lesions (31%) had pathologic confirmation. Lesions were grouped based on pathological diagnosis and best radiologic diagnosis when pathology was not available. Wilcoxon rank sum tests were used to test for differences in SUV max among paragangliomas, schwannomas, and meningiomas. Receiver operator characteristic curves were constructed., Results: Paragangliomas had a significantly greater 68 Ga-DOTATATE uptake (median SUV max , 62; interquartile range [IQR], 89) than nonparagangliomas. Schwannomas had near-zero 68 Ga-DOTATATE uptake (median SUV max , 2; IQR, 1). Intermediate 68 Ga-DOTATATE uptake was seen for meningiomas (median SUV max , 19; IQR, 6) and other neuroaxis lesions (median SUV max , 7; IQR, 9). Receiver operator characteristic analysis demonstrated an area under the curve of 0.87 for paragangliomas versus all other lesions and 0.97 for schwannomas versus all other lesions., Conclusions: Marked 68 Ga-DOTATATE uptake (>50 SUV max ) favors a diagnosis of paraganglioma, although paragangliomas exhibit a wide variability of uptake. Low to moderate level 68 Ga-DOTATATE uptake is nonspecific and may represent diverse pathophysiology including paraganglioma, meningioma, and other neuroaxis tumors but essentially excludes schwannomas, which exhibited virtually no uptake., Competing Interests: Conflicts of interest and sources of funding: none declared., (Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Paragangliomas are the most common tumors at jugular foramen and pose a great surgical challenge. Careful clinical history and physical examination must be performed to adequately evaluate neurological deficits and its chronologic evolution, also to delineate an overview of the patient performance status. Complete imaging evaluation including MRI and CT scans should be performed, and angiography is a must to depict tumor blood supply and sigmoid sinus/internal jugular vein patency. Screening for multifocal paragangliomas is advisable, with a whole-body imaging. Laboratory investigation of endocrine function of the tumor is necessary, and adrenergic tumors may be associated with synchronous lesions. Preoperative prepare with alpha-blockage is advisable in norepinephrine/epinephrine-secreting tumors; however, it is not advisable in exclusively dopamine-secreting neoplasms. Best surgical candidates are young otherwise healthy patients with smaller lesions; however, treatment should be individualized each case. Variations of infratemporal fossa approach are employed depending on extensions of the mass. Regarding facial nerve management, we avoid to expose or reroute it if there is preoperative function preservation and prefer to work around facial canal in way of a fallopian bridge technique. If there is preoperative facial nerve compromise, the mastoid segment of the nerve is exposed, and it may be grafted if invaded or just decompressed. A key point is to preserve the anteromedial wall of internal jugular vein if there is preoperative preservation of lower cranial nerves. Careful multilayer closure is essential to avoid at most cerebrospinal fluid leakage. Residual tumors may be reoperated if growing and presenting mass effect or be candidate for adjuvant stereotactic radiosurgery., (© 2024. The Author(s), under exclusive license to Springer Nature Switzerland AG.)