Contemporary Imaging and Reporting Strategies for Head and Neck Cancer: MRI, FDG PET/MRI, NI-RADS, and Carcinoma of Unknown Primary-AJR Expert Panel Narrative Review.

CT, MRI, and FDG PET/CT play major roles in the diagnosis, staging, treatment planning, and surveillance of head and neck cancers. Nonetheless, an evolving understanding of head and neck cancer pathogenesis, advances in imaging techniques, changing treatment regimens, and a lack of standardized guidelines have led to areas of uncertainty in the imaging of head and neck cancer. This narrative review aims to address four issues in the contemporary imaging of head and neck cancer. The first issue relates to the standard and advanced sequences that should be included in MRI protocols for head and neck cancer imaging. The second issue relates to approaches to surveillance imaging after treatment of head and neck cancer, including the choice of imaging modality, the frequency of surveillance imaging, and the role of standardized reporting through the Neck Imaging Reporting and Data System. The third issue relates to the role of imaging in the setting of neck carcinoma of unknown primary. The fourth issue relates to the role of simultaneous PET/MRI in head and neck cancer evaluation. The authors of this review provide consensus opinions for each issue.

18F-FSPG PET/CT Imaging of System xC- Transporter Activity in Patients with Primary and Metastatic Brain Tumors.

Background The PET tracer (4S)-4-(3-[18F]fluoropropyl)-l-glutamate (18F-FSPG) targets the system xC- cotransporter, which is overexpressed in various tumors. Purpose To assess the role of 18F-FSPG PET/CT in intracranial malignancies. Materials and Methods Twenty-six patients (mean age, 54 years ± 12; 17 men; 48 total lesions) with primary brain tumors (n = 17) or brain metastases (n = 9) were enrolled in this prospective, single-center study (ClinicalTrials.gov identifier: NCT02370563) between November 2014 and March 2016. A 30-minute dynamic brain 18F-FSPG PET/CT scan and a static whole-body (WB) 18F-FSPG PET/CT scan at 60-75 minutes were acquired. Moreover, all participants underwent MRI, and four participants underwent fluorine 18 (18F) fluorodeoxyglucose (FDG) PET imaging. PET parameters and their relative changes were obtained for all lesions. Kinetic modeling was used to estimate the 18F-FSPG tumor rate constants using the dynamic and dynamic plus WB PET data. Imaging parameters were correlated to lesion outcomes, as determined with follow-up MRI and/or pathologic examination. The Mann-Whitney U test or Student t test was used for group mean comparisons. Receiver operating characteristic curve analysis was used for performance comparison of different decision measures. Results 18F-FSPG PET/CT helped identify all 48 brain lesions. The mean tumor-to-background ratio (TBR) on the whole-brain PET images at the WB time point was 26.6 ± 24.9 (range: 2.6-150.3). When 18F-FDG PET was performed, 18F-FSPG permitted visualization of non-18F-FDG-avid lesions or allowed better lesion differentiation from surrounding tissues. In participants with primary brain tumors, the predictive accuracy of the relative changes in influx rate constant Ki and maximum standardized uptake value to discriminate between poor and good lesion outcomes were 89% and 81%, respectively. There were significant differences in the 18F-FSPG uptake curves of lesions with good versus poor outcomes in the primary brain tumor group (P < .05) but not in the brain metastases group. Conclusion PET/CT imaging with (4S)-4-(3-[18F]fluoropropyl)-l-glutamate (18F-FSPG) helped detect primary brain tumors and brain metastases with a high tumor-to-background ratio. Relative changes in 18F-FSPG uptake with multi-time-point PET appear to be helpful in predicting lesion outcomes. Clinical trial registration no. NCT02370563 © RSNA, 2022 Online supplemental material is available for this article.

Optic Perineuritis Associated With Cryptococcal Meningitis Presenting With a "Hot Orbit" in a Patient With Chronic Lymphocytic Leukemia.

ABSTRACT: A 75-year-old man presented with 3 days of progressive left retro-orbital pain, eyelid swelling, tearing, and pain with extraocular movement. His medical history was significant for type II diabetes mellitus and chronic lymphocytic leukemia, stable on no therapy since diagnosis 8 years prior. The initial examination was significant for diffuse restriction of left ocular motility, marked lid edema, and mild dyschromatopsia. Computed tomography demonstrated asymmetric left periorbital soft tissue swelling and intraconal fat stranding with an irregular left optic nerve sheath complex and clear paranasal sinuses. He was hospitalized for orbital cellulitis and treated empirically with broad-spectrum intravenous antibiotics, but his visual acuity declined over the ensuing 2 days. Subsequent MRI demonstrated left-greater-than-right circumferential optic nerve sheath enhancement, and leptomeningeal enhancement. An orbital biopsy demonstrated monoclonal B-cell lymphocyte aggregation, whereas a lumbar puncture was positive for Cryptococcus antigen with subsequent demonstration of abundant Cryptococcus by Papanicolaou stain. The final diagnosis was optic perineuritis secondary to cryptococcal meningitis presenting with orbital inflammation. Although his clinical course was complicated by immune reconstitution inflammatory syndrome, symptoms and signs of optic neuropathy ultimately resolved after 1 month of intensive antifungal therapy.

COVID-19-induced anosmia associated with olfactory bulb atrophy.

As the global COVID-19 pandemic evolves, our knowledge of the respiratory and non-respiratory symptoms continues to grow. One such symptom, anosmia, may be a neurologic marker of coronavirus infection and the initial presentation of infected patients. Because this symptom is not routinely investigated by imaging, there is conflicting literature on neuroimaging abnormalities related to COVID-19-related anosmia. We present a novel case of COVID-19 anosmia with definitive olfactory bulb atrophy compared with pre-COVID imaging. The patient had prior MR imaging related to a history of prolactinoma that provided baseline volumes of her olfactory bulbs. After a positive diagnosis of COVID-19 and approximately 2 months duration of anosmia, an MRI was performed that showed clear interval olfactory bulb atrophy. This diagnostic finding is of prognostic importance and indicates that the olfactory entry point to the brain should be further investigated to improve our understanding of COVID infectious pathophysiology.

Arterial-spin labeling MRI identifies residual cerebral arteriovenous malformation following stereotactic radiosurgery treatment.

BACKGROUND AND PURPOSE: Brain arteriovenous malformation (AVM) treatment by stereotactic radiosurgery (SRS) is effective, but AVM obliteration following SRS may take two years or longer. MRI with arterial-spin labeling (ASL) may detect brain AVMs with high sensitivity. We determined whether brain MRI with ASL may accurately detect residual AVM following SRS treatment. MATERIALS AND METHODS: We performed a retrospective cohort study of patients who underwent brain AVM evaluation by DSA between June 2010 and June 2015. Inclusion criteria were: (1) AVM treatment by SRS, (2) follow-up MRI with ASL at least 30 months after SRS, (3) DSA within 3 months of the follow-up MRI with ASL, and (4) no intervening AVM treatment between the MRI and DSA. Four neuroradiologists blindly and independently reviewed follow-up MRIs. Primary outcome measure was residual AVM indicated by abnormal venous ASL signal. RESULTS: 15 patients (12 females, mean age 29 years) met inclusion criteria. There were three posterior fossa AVMs and 12 supratentorial AVMs. Spetzler-Martin (SM) Grades were: SM1 (8%), SM2 (33%), SM3 (17%), SM4 (25%), and SM5 (17%). DSA demonstrated residual AVM in 10 patients. The pooled sensitivity, specificity, positive predictive value, and negative predictive value of venous ASL signal for predicting residual AVM were 100% (95% CI: 0.9-1.0), 95% (95% CI: 0.7-1.0), 98% (95% CI: 0.9-1.0), and 100% (95% CI: 0.8-1.0), respectively. High inter-reader agreement as found by Fleiss' Kappa analysis (k = 0.92; 95% CI: 0.8-1.0; P < 0.0001). CONCLUSIONS: ASL is highly sensitive and specific in the detection of residual cerebral AVM following SRS treatment.

Cerebral Blood Flow Predicts the Infarct Core: New Insights From Contemporaneous Diffusion and Perfusion Imaging.

Background and Purpose- The aim of this study is to determine the spatial and volumetric accuracy of infarct core estimates from relative cerebral blood flow (rCBF) by comparison with near-contemporaneous diffusion-weighted imaging (DWI), and evaluate whether it is sufficient for patient triage to reperfusion therapies. Methods- One hundred ninety-three patients enrolled in the DEFUSE 2 (Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution) and SENSE 3 (Sensitivity Encoding) stroke studies were screened, and 119 who underwent acute magnetic resonance imaging with DWI and perfusion imaging within 24 hours of onset were included. Infarct core was estimated using reduced rCBF at 12 thresholds (<0.20-<0.44) and compared against DWI (apparent diffusion coefficient <620 10-6mm2/s). For each threshold, volumetric agreement between the rCBF and DWI core estimates was assessed using Bland-Altman, correlation, and linear regression analyses; spatial agreement was assessed using receiver operating characteristic analysis. Results- An rCBF threshold of 0.32 yielded the smallest mean absolute volume difference (14.7 mL), best linear regression fit (R2=0.84), and best spatial agreement (Youden index, 0.38; 95% CI, 0.34-0.41) between rCBF and DWI, with high correlation (r=0.91, P<0.05), a small mean volume difference (1.3 mL) and no fixed bias (P<0.05). At this threshold, 110 of 119 (92.4%) patients were correctly triaged when applying 70 mL as the volume limit for thrombectomy. Spatial agreement was better for prediction of large infarcts (>70 mL) than small infarcts (≤70 mL), with Youden indices of 0.53 (95% CI, 0.49-0.56) and 0.34 (95% CI, 0.30-0.37), respectively. Conclusions- Strong correlation and agreement with near-contemporaneous DWI indicate that infarct core estimates obtained using rCBF are sufficiently accurate for patient triage to reperfusion therapies. The identified optimal rCBF threshold of 0.32 closely approximates the threshold currently used in clinical practice.

Automated Detection of Intracranial Large Vessel Occlusions on Computed Tomography Angiography: A Single Center Experience.

Background and Purpose- Endovascular thrombectomy is highly effective in acute ischemic stroke patients with an anterior circulation large vessel occlusion (LVO), decreasing morbidity and mortality. Accurate and prompt identification of LVOs is imperative because these patients have large volumes of tissue that are at risk of infarction without timely reperfusion, and the treatment window is limited to 24 hours. We assessed the accuracy and speed of a commercially available fully automated LVO-detection tool in a cohort of patients presenting to a regional hospital with suspected stroke. Methods- Consecutive patients who underwent multimodal computed tomography with thin-slice computed tomography angiography between January 1, 2017 and December 31, 2018 for suspected acute ischemic stroke within 24 hours of onset were retrospectively identified. The multimodal computed tomographies were assessed by 2 neuroradiologists in consensus for the presence of an intracranial anterior circulation LVO or M2-segment middle cerebral artery occlusion (the reference standard). The patients' computed tomography angiographies were then processed using an automated LVO-detection algorithm (RAPID CTA). Receiver-operating characteristic analysis was used to determine sensitivity, specificity, and negative predictive value of the algorithm for detection of (1) an LVO and (2) either an LVO or M2-segment middle cerebral artery occlusion. Results- CTAs from 477 patients were analyzed (271 men and 206 women; median age, 71; IQR, 60-80). Median processing time was 158 seconds (IQR, 150-167 seconds). Seventy-eight patients had an anterior circulation LVO, and 28 had an isolated M2-segment middle cerebral artery occlusion. The sensitivity, negative predictive value, and specificity were 0.94, 0.98, and 0.76, respectively for detection of an intracranial LVO and 0.92, 0.97, and 0.81, respectively for detection of either an intracranial LVO or M2-segment middle cerebral artery occlusion. Conclusions- The fully automated algorithm had very high sensitivity and negative predictive value for LVO detection with fast processing times, suggesting that it can be used in the emergent setting as a screening tool to alert radiologists and expedite formal diagnosis.

Imaging changes over 18 months following stereotactic radiosurgery for brain metastases: both late radiation necrosis and tumor progression can occur.

Following stereotactic radiosurgery (SRS) for brain metastases, the median time range to develop adverse radiation effect (ARE) or radiation necrosis is 7-11 months. Similarly, the risk of local tumor recurrence following SRS is < 5% after 18 months. With improvements in systemic therapy, patients are living longer and are at risk for both late (defined as > 18 months after SRS) tumor recurrence and late ARE, which have not previously been well described. An IRB-approved, retrospective review identified patients treated with SRS who developed new MRI contrast enhancement > 18 months following SRS. ARE was defined as stabilization/shrinkage of the lesion over time or pathologic confirmation of necrosis, without tumor. Local failure (LF) was defined as continued enlargement of the lesion over time or pathologic confirmation of tumor. We identified 16 patients, with a median follow-up of 48.2 months and median overall survival of 73.0 months, who had 19 metastases with late imaging changes occurring a median of 32.9 months (range 18.5-63.2 months) after SRS. Following SRS, 12 lesions had late ARE at a median of 33.2 months and 7 lesions had late LF occurring a median of 23.6 months. As patients with cancer live longer and as SRS is increasingly utilized for treatment of brain metastases, the incidence of these previously rare imaging changes is likely to increase. Clinicians should be aware of these late events, with ARE occurring up to 5.3 years and local failure up to 3.8 years following SRS in our cohort.

Detection of Cortical Venous Drainage and Determination of the Borden Type of Dural Arteriovenous Fistula by Means of 3D Pseudocontinuous Arterial Spin-Labeling MRI.

OBJECTIVE: The risk of intracranial dural arteriovenous fistula is linked to its pattern of venous drainage (Borden type), in particular the presence of cortical venous drainage. The purpose of this study was to assetss the accuracy of 3D pseudocontinuous arterial spin-labeling (ASL) MRI for noninvasive delineation of venous drainage. MATERIALS AND METHODS: This retrospective study included 34 patients with a dural arteriovenous fistula who had undergone both digital subtraction angiography (DSA) and 3D pseudocontinuous ASL MRI. Two neuroradiologists blinded to the DSA results independently assessed ASL images for the presence of cortical vein hyperintensity (cortical venous drainage) and the distribution of venous hyperintensity (Borden type). DSA was used as the reference standard. The sensitivity and specificity of 3D pseudocontinuous ASL MRI for the detection of cortical venous drainage were determined. Intermodality and interobserver agreement for Borden type was determined by use of the weighted kappa statistic. RESULTS: Three-dimensional pseudocontinuous ASL MRI had high sensitivity (91%) and specificity (96%) for the detection of cortical venous drainage. Borden type was correctly identified with very good intermodality (weighted κ = 0.82) and interobserver (weighted κ = 0.85) agreement in 88% of patients. CONCLUSION: Three-dimensional pseudocontinuous ASL MRI is highly accurate for the detection of cortical venous drainage and determination of Borden type. With this technique, high-risk fistulas requiring treatment can be reliably differentiated from low-risk lesions. Although it cannot replace DSA, incorporating 3D pseudocontinuous ASL into an MRI protocol for assessment of dural arteriovenous fistula can facilitate treatment planning.

Ameloblastoma: a clinical review and trends in management.

Ameloblastoma is a rare odontogenic neoplasm of the mandible and maxilla, with multiple histologic variants, and high recurrence rates if improperly treated. The current mainstay of treatment is wide local excision with appropriate margins and immediate reconstruction. Here we review the ameloblastoma literature, using the available evidence to highlight the change in management over the past several decades. In addition, we explore the recent molecular characterization of these tumors which may point towards new potential avenues of personalized treatment.

Glioblastoma Multiforme Recurrence: An Exploratory Study of (18)F FPPRGD2 PET/CT.

PURPOSE: To prospectively evaluate fluorine 18 ((18)F) 2-fluoropropionyl-labeled PEGylated dimeric arginine-glycine-aspartic acid (RGD) peptide (PEG3-E[c{RGDyk}]2) (FPPRGD2) positron emission tomography (PET) in patients with glioblastoma multiforme (GBM). MATERIALS AND METHODS: The institutional review board approved this HIPAA-compliant protocol. Written informed consent was obtained from each patient. (18)F FPPRGD2 uptake was measured semiquantitatively in the form of maximum standardized uptake values (SUV(max)) and uptake volumes before and after treatment with bevacizumab. Vital signs and laboratory results were collected before, during, and after the examinations. A nonparametric version of multivariate analysis of variance was used to assess safety outcome measures simultaneously across time points. A paired two-sample t test was performed to compare SUV(max). RESULTS: A total of 17 participants (eight men, nine women; age range, 25-65 years) were enrolled prospectively. (18)F FPPRGD2 PET/computed tomography (CT), (18)F fluorodeoxyglucose (FDG) PET/CT, and brain magnetic resonance (MR) imaging were performed within 3 weeks, prior to the start of bevacizumab therapy. In eight of the 17 patients (47%), (18)F FPPRGD2 PET/CT was repeated 1 week after the start of bevacizumab therapy; six patients (35%) underwent (18)F FPPRGD2 PET/CT a third time 6 weeks after starting bevacizumab therapy. There were no changes in vital signs, electrocardiographic findings, or laboratory values that qualified as adverse events. One patient (6%) had recurrent GBM identified only on (18)F FPPRGD2 PET images, and subsequent MR images enabled confirmation of recurrence. Of the 17 patients, 14 (82%) had recurrent GBM identified on (18)F FPPRGD2 PET and brain MR images, while (18)F FDG PET enabled identification of recurrence in 13 (76%) patients. Two patients (12%) had no recurrent GBM. CONCLUSION: (18)F FPPRGD2 is a safe PET radiopharmaceutical that has increased uptake in GBM lesions. Larger cohorts are required to confirm these preliminary findings.

Metronidazole-induced encephalopathy: not always a reversible situation.

BACKGROUND: Metronidazole is a nitroimidazole antimicrobial drug prescribed to treat infections caused by anaerobic bacteria and protozoa. Uncommonly, it causes central nervous system (CNS) toxicity manifesting as metronidazole-induced encephalopathy (MIE). METHODS: Case report. RESULTS: A 65-year-old woman with hepatitis B cirrhosis (Child-Pugh class C, MELD 21) developed progressive encephalopathy to GCS 4 during a 3-week course of metronidazole for cholecystitis. Initial MRI was consistent with CNS metronidazole toxicity, with symmetrical T2 hyperintensity and generally restricted diffusion in bilateral dentate nuclei, corpus callosum, midbrain, superior cerebellar peduncles, internal capsules, and cerebral white matter. Laboratory values did not demonstrate significant electrolyte shifts, and continuous EEG was without seizure. High-dose thiamine was empirically administered. Lumbar puncture was not performed due to coagulopathy and thrombocytopenia. Despite discontinuation of metronidazole and keeping ammonia levels near normal, the patient did not improve. MRI was repeated 1 week after discontinuation of metronidazole. Although there was decreased DWI hyperintensity in the dentate nuclei, diffuse T2 hyperintensity persisted and even progressed in the brainstem, basal ganglia, and subcortical white matter. Petechial hemorrhages developed in bilateral corticospinal tracts and subcortical white matter. T1 hypointensity appeared in the corpus callosum. She was transitioned to comfort measures only and died 12 days later. CONCLUSION: MIE is an uncommon adverse effect of treatment with metronidazole that characteristically affects the dentate nuclei but may also involve the brainstem, corpus callosum, subcortical white matter, and basal ganglia. While the clinical symptoms and neuroimaging changes are usually reversible, persistent encephalopathy with poor outcome may occur.

Sensitivity of Magnetic Resonance Imaging in Detection of Choroidal Metastases.

Introduction: The objective of this study was to determine the sensitivity of brain magnetic resonance imaging (MRI) in the detection of choroidal metastasis (CM) from systemic primary cancers. Methods: A retrospective chart review identified patients with clinically confirmed CM seen on the Oncology Service (Byers Eye Institute) between January 2018 and March 2022. Patients had an MRI brain and/or orbits performed within 3 months of CM diagnosis. Evaluation of CM detection by MRI was then divided into two parts: an initial "standard read," where determination of CM detection was based solely on the original radiology report, to reflect real-world performance, and a subsequent "dedicated read," for which a board-certified neuroradiologist, blinded to the laterality and location of the CM, reevaluated the studies to provide an objective "gold standard" interpretation regarding the radiographic detection of CM. Results: The study included 42 eyes of 40 patients with confirmed CM. On standard read, MRI detection of CM occurred in 21 of 42 eyes (50%), with no significant difference between MRI brain and orbit protocols (p = 0.249). Features associated with improved detection were increased tumor basal diameter (p < 0.001) and ultrasonographic tumor thickness (p = 0.003). On dedicated read, MRI detection of CM improved to 26 of 33 eyes (76%; limited to eyes with full complement of pre- and post-gadolinium sequences). Post-gadolinium 3D fluid-attenuated inversion recovery (FLAIR) sequence with fat suppression was the most sensitive (88%) for CM detection. 42% and 58% of lesions were visualized using conventional pre-gadolinium T1- and T2-weighted imaging, respectively. Conclusions: MRI sensitivity to detect CM improved from 50% to 76% with focused reinterpretation. Increased utilization of the post-gadolinium 3D FLAIR sequence and increased ocular scrutiny in cancer patients undergoing brain imaging may facilitate earlier diagnosis of CM.

NeuroMix with MR Angiography: A Fast MR Protocol to Reduce Head and Neck CT Angiography for Patients with Acute Neurological Presentations.

BACKGROUND AND PURPOSE: Overuse of computed tomography (CT)-based cerebrovascular imaging in the emergency department (ED) and inpatient settings, notably CT angiography of the head and neck (CTAHN) for minor and non-focal neurological presentations, stresses imaging services and exposes patients to radiation and contrast. Furthermore, such CT-based imaging is often insufficient for definitive diagnosis, necessitating additional MR imaging. Recent advances in fast MRI may allow for timely assessment and reduced need for CTAHN in select populations. MATERIALS AND METHODS: We identified inpatients or ED patients who underwent CTAHN (including non-contrast and post-contrast CTH, with or without CT perfusion [CTP] imaging) followed within 24 hours by a 3T MRI study that included NeuroMix (an unenhanced 2.5 min multi-contrast sequence) and intracranial time-of-flight MR angiography (MRA; a 5 min sequence) during a 9-month period (April to December 2022). Cases were classified by 4 radiologists in consensus as to whether NeuroMix and NeuroMix+MRA detected equivalent findings, detected unique findings, or missed findings relative to CTAHN. RESULTS: 174 cases (mean age 67±16 yrs; 56% female) met the inclusion criteria. NeuroMix alone and NeuroMix+MRA protocols were determined to be equivalent or better compared to CTAHN in 71% and 95% of patients, respectively. NeuroMix always provided equivalent or better assessment of the brain parenchyma, with unique findings on NeuroMix and NeuroMix+MRA in 35% and 36% of cases, respectively, most commonly acute infarction or multiple microhemorrhages. In 8/174 cases (5%), CTAHN identified vascular abnormalities not seen on the NeuroMix+MRA protocol due to CTAHN's wider coverage of the cervical arteries. CONCLUSIONS: A fast MR imaging protocol consisting of NeuroMix+MRA provided equivalent or better information compared to CTAHN in 95% of cases in our population of patients with an acute neurological presentation. The findings provide a deeper understanding of the benefits and challenges of a fast unenhanced MR-first approach with NeuroMix+MRA, which could be used to design prospective trials in select patient groups, with the potential to reduce radiation dose, mitigate adverse contrast-related patient and environmental effects, and lessen the burden on radiologists and healthcare systems. ABBREVIATIONS: CTAHN = CTA Head and Neck including non-contrast and delayed post-contrast CT Head with or without CT perfusion, NeuroMix = unenhanced multi-contrast MR brain sequence.

A rare non-gadolinium enhancing sarcoma brain metastasis with microenvironment dominated by tumor-associated macrophages.

Brain metastases occur in 1% of sarcoma cases and are associated with a median overall survival of 6 months. We report a rare case of a brain metastasis with unique radiologic and histopathologic features in a patient with low grade fibromyxoid sarcoma (LGFMS) previously treated with immune checkpoint inhibitor (ICI) therapy. The lone metastasis progressed in the midbrain tegmentum over 15 months as a non-enhancing, T2-hyperintense lesion with peripheral diffusion restriction, mimicking a demyelinating lesion. Histopathology of the lesion at autopsy revealed a rich infiltrate of tumor-associated macrophages (TAMs) with highest density at the leading edge of the metastasis, whereas there was a paucity of lymphocytes, suggestive of an immunologically cold environment. Given the important immunosuppressive and tumor-promoting functions of TAMs in gliomas and carcinoma/melanoma brain metastases, this unusual case provides an interesting example of a dense TAM infiltrate in a much rarer sarcoma brain metastasis.

MRI Safety of Stapes Prostheses: A Systematic Review.

OBJECTIVE: To assess magnetic resonance imaging (MRI) safety of stapes prostheses. DATA SOURCES: Ovid MEDLINE, Embase, Cochrane Central Register of Controlled Trials, Web of Science, and Scopus databases were searched from inception to November 2021 following PRISMA guidelines. REVIEW METHODS: Studies reporting evidence of stapes prosthesis displacement or interaction in adult or pediatric implant recipients undergoing MRI. Cadaveric, animal, and basic studies with nonhuman data were also included. RESULTS: From an initial search of 123 articles, 42 full-text studies were evaluated for eligibility and 19 studies that met the inclusion criteria were included. Motion artifact was reported in a few stainless steel prosthesis types in vitro; however, such displacement was not observed in human cadaver temporal bone studies and had no adverse reported outcomes. A small subgroup of patients in the 1980s received a ferromagnetic stainless steel stapes implant that was recalled and has not been used since 1987. Patients with implants performed in the 1980s should be directed to 1.5T scanners from an abundance of caution. CONCLUSION: Modern (post-1987) stapes prostheses do not pose a risk in vivo when exposed to the magnetic fields of MRI scanners.

International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors.

BACKGROUND: Sinonasal neoplasms, whether benign and malignant, pose a significant challenge to clinicians and represent a model area for multidisciplinary collaboration in order to optimize patient care. The International Consensus Statement on Allergy and Rhinology: Sinonasal Tumors (ICSNT) aims to summarize the best available evidence and presents 48 thematic and histopathology-based topics spanning the field. METHODS: In accordance with prior International Consensus Statement on Allergy and Rhinology documents, ICSNT assigned each topic as an Evidence-Based Review with Recommendations, Evidence-Based Review, and Literature Review based on the level of evidence. An international group of multidisciplinary author teams were assembled for the topic reviews using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses format, and completed sections underwent a thorough and iterative consensus-building process. The final document underwent rigorous synthesis and review prior to publication. RESULTS: The ICSNT document consists of four major sections: general principles, benign neoplasms and lesions, malignant neoplasms, and quality of life and surveillance. It covers 48 conceptual and/or histopathology-based topics relevant to sinonasal neoplasms and masses. Topics with a high level of evidence provided specific recommendations, while other areas summarized the current state of evidence. A final section highlights research opportunities and future directions, contributing to advancing knowledge and community intervention. CONCLUSION: As an embodiment of the multidisciplinary and collaborative model of care in sinonasal neoplasms and masses, ICSNT was designed as a comprehensive, international, and multidisciplinary collaborative endeavor. Its primary objective is to summarize the existing evidence in the field of sinonasal neoplasms and masses.

Impact of positron emission tomography/computed tomography surveillance at 12 and 24 months for detecting head and neck cancer recurrence.

BACKGROUND: In head and neck cancer (HNC), 3-month post-treatment positron emission tomography (PET)/computed tomography (CT) reliably identifies persistent/recurrent disease. However, further PET/CT surveillance has unclear benefit. The impact of post-treatment PET/CT surveillance on outcomes is assessed at 12 and 24 months. METHODS: A 10-year retrospective analysis of HNC patients was carried out with long-term serial imaging. Imaging at 3 months included either PET/CT or magnetic resonance imaging, with all subsequent imaging comprised of PET/CT. PET/CT scans at 12 and 24 months were evaluated only if preceding interval scans were negative. Of 1114 identified patients, 284 had 3-month scans, 175 had 3- and 12-month scans, and 77 had 3-, 12-, and 24-month scans. RESULTS: PET/CT detection rates in clinically occult patients were 9% (15 of 175) at 12 months, and 4% (3 of 77) at 24 months. No difference in outcomes was identified between PET/CT-detected and clinically detected recurrences, with similar 3-year disease-free survival (41% vs 46%, P = .91) and 3-year overall survival (60% vs 54%, P = .70) rates. Compared with 3-month PET/CT, 12-month PET/CT demonstrated fewer equivocal reads (26% vs 10%, P < .001). Of scans deemed equivocal, 6% (5 of 89) were ultimately found to be positive. CONCLUSIONS: HNC patients with negative 3-month imaging appear to derive limited benefit from subsequent PET/CT surveillance. No survival differences were observed between PET/CT-detected and clinically detected recurrences, although larger prospective studies are needed for further investigation.