[Results of a survey on the current management of chronic rhinosinusitis with nasal polyps in Germany]. / Ergebnisse einer Umfrage zur aktuellen Behandlung der chronischen Rhinosinusitis mit nasalen Polypen.

INTRODUCTION: With a prevalence of 0.55% to 4%, chronic rhinosinusitis with nasal polyps (CRSwNP) is a relevant part of the daily work of German otolaryngologists. The aim of the questionnaire-based data collection was to assess the current treatment status of CRSwNP in Germany. MATERIAL AND METHODS: For this purpose, 24 questions within an anonymized online questionnaire were sent to all German ENT departments. RESULTS: Of 160 contacted ENT departments, 50 participated in the survey (31.3%). Among these, 76% performed more than 100 sinus surgeries annually and 38% treated more than 50 patients with biologics. Saline irrigations (80%) and intranasal glucocorticoids (GCS, 96%) were the most common conservative therapies. Systemic GCSs (52%) and intranasal GCS irrigation (20%) were less common. 80% of departments used biologics in the therapy of CRSwNP with an overall preference for dupilumab (70%). For therapy of aspirin intolerance, biologics (52%) were preferred to aspirin desensitization (26%). Prior to treatment with biologics clinical workup included the nasal polyp score (90%), the SNOT-22 questionnaire (84%), surrogate markers of type 2 inflammation (60%-72%), and computer tomography (50%). Final treatment success was assessed after 24 weeks (50%). CONCLUSION: Mostly, the responding departments followed German and European recommendations for diagnosis and therapy of CRSwNP. Therapy with biologics is widely used. The value of preoperative systemic GCS and the frequent performance of CT before initiation of therapy with a biologic should be debated in regard to its currently widespread use.

Concordance Analysis of the Pressure Chamber and Tubomanometer According to Estève for the Determination of Eustachian Tube Opening Pressure.

INTRODUCTION: For the diagnosis of Eustachian tube dysfunction (ETD), clinical procedures such as tympanometry, micro-otoscopy, and maneuvers according to Toynbee and Valsalva only allow an indirect assessment for the moment. With a prevalence of up to 5%, the selection of patients with ETD and its subtypes is clinically relevant. Dynamic methods of Eustachian tube function assessment include a hypo/hyperbaric pressure chamber and Estève's tubomanometer (TMM). One method of assessing ETD is the evaluation of Eustachian tube opening pressure (ETOP). MATERIAL AND METHODS: We performed a concordance analysis between pressure chamber and TMM to determine ETOP. For this purpose, we analyzed the measurements of both methods from 28 healthy subjects using Bland-Altman plots, regression according to Passing-Bablok and Lin's concordance correlations coefficient. The maximum tolerated clinical deviation of measured values was set at 10%. RESULTS: A maximum of 53 measurements of ETOP between pressure chamber and TMM were compared. Mean ETOP for TMM was 28.7 hPa, passive opening was 32 hPa, Toynbee maneuver was 28.4 hPa, and Valsalva maneuver was 54.6 hPa. Concordance analysis revealed following results: passive opening versus TMM: Bland-Altman mean difference 3.3 hPa, limits of agreement ±31.8 hPa; Passing-Bablok regression y = 0.67x + 9.36; Lin's rccc = 0.18. Toynbee versus TMM: Bland-Altman mean difference 0.7 hPa, limits of agreement ±35.8 hPa; Passing-Bablok regression y = 0.47x + 14.03; Lin's rccc = 0.14. Valsalva versus TMM: Bland-Altman mean difference 24.2 hPa, limits of agreement ±117.5 hPa; Passing-Bablok regression y = 0.17x + 25.12; Lin's rccc = 0.18. CONCLUSION: Estève's tubomanometer and pressure chamber measurements of ETOP are not concordant. The two methods cannot be interchanged without reservation.

Two different methods to digitally visualize continuous electrocochleography potentials during cochlear implantation: a first description of feasibility.

PURPOSE: The study explores the potential of real-time electrocochleographic potentials (ECochG) visualization during electrode insertion using digital microscopes such as RoboticScope (BHS®). Collaborative software development of the MAESTRO Software (MED-EL®) offers continuous ECochG monitoring during implantation and postoperative hearing evaluation, addressing previous time constraints. The study aims to assess software applicability and the impact of real-time visualization on long-term residual hearing preservation. METHODS: Eight patients with residual hearing underwent cochlear implantation with Flex26 or Flex28 electrode according to the Otoplan evaluation. ECochG responses were measured and visualized during electrode insertion, with insertion times recorded. Two randomized display methods (graph and arrows) tracked ECochG potentials. Postoperative behavioral thresholds determined hearing preservation. Successful real-time intraoperative ECochG visualization was achieved in all cases, enabling surgeon adaptation. Mean electrode insertion time was 114 s, with postoperative thresholds comparable to preoperative values. Visualization did not affect surgeon workload. ECochG amplitudes differed between patients with and without residual hearing. CONCLUSION: The study demonstrates effective implementation of advanced ECochG software combined with real-time visualization, enabling residual hearing preservation during CI. Visualization had no apparent effect on surgeon performance or workload. Future investigation involving a larger population will assess the long-term impact of ECochG on hearing threshold and structure preservation.

Digital live imaging of intraoperative electrocochleography during cochlear implantation: the first 50 patients.

INTRODUCTION: Real-time visualization of intraoperative electrocochleography (ECochG) potentials via a digital microscope during cochlear implantation can provide direct feedback during electrode insertion. The aim of this prospective, randomized study of 50 patients was to obtain long-term data with a focus on residual hearing preservation and speech understanding. MATERIAL AND METHODS: Cochlear implantations were performed in 50 patients (26 female, 24 male) with residual hearing using a digital microscope. Patients were randomized into two groups. Intraoperative ECochG potentials were either displayed directly in the surgeon's field of view (picture-in-picture display, PiP) or not directly in the field of view (without picture-in-picture display, without PiP). Residual hearing preservation and speech comprehension were recorded within a 1-year follow-up period, compared between groups (PiP versus without PiP) and to a control group of 26 patients implanted without ECochG. RESULTS: Mean insertion time was significantly longer in the picture-in-picture group (p = 0.025). Residual hearing preservation after 6 weeks at 250 Hz was significantly better in the picture-in-picture group (p = 0.017). After one year, 76% of patients showed residual hearing in the picture-in-picture group (62% without picture-in-picture technique, p = n.s.). Use of the picture-in-picture technique resulted in better long-term pure tone residual hearing preservation at 250, 500, and 1000 Hz. Speech intelligibility improved by 46% in the picture-in-picture group (38% without picture-in-picture). DISCUSSION: This study is the first to describe long-term results in a large cohort of cochlear implant patients in whom digital visualization of intraoperative ECochG was used. Our results show that visualization of intraoperative ECochG has a positive effect on residual hearing preservation.

[Increased rate of complications of pediatric acute otitis media and sinusitis in 2022/2023]. / Häufung von Komplikationen der akuten Otitis media und Sinusitis bei Kindern 2022/2023.

BACKGROUND: Acute mastoiditis and orbital complications of acute rhinosinusitis are among the most common complications of pediatric infections in otolaryngology. OBJECTIVE: The aim of this study was to investigate the frequency of pediatric acute mastoiditis in the setting of acute otitis media as well as pediatric orbital complications in the setting of acute rhinosinusitis. Data from before the pandemic were compared to data after the end of the COVID-19 restrictions. MATERIALS AND METHODS: Included were hospitalized children who presented with acute mastoiditis from acute otitis media or with orbital complications from acute rhinosinusitis during the period from April 2017 to March 2023. Compared were three periods using descriptive statistics: April 2017 to March 2020 (before the pandemic in Germany), April 2020 to March 2022 (during the contact restrictions of the pandemic), and April 2022 to March 2023 (after the contact restrictions were lifted). RESULTS: A total of 102 children (43 with acute mastoiditis, 42%, and 59 with orbital complications of acute sinusitis, 58%) were included. During the 2022/2023 period, more than twice as many children with acute mastoiditis and approximately three times as many children with orbital complications of acute rhinosinusitis were hospitalized compared to the average of the periods 2017/2018, 2018/2019, and 2019/2020. In the 2021/2022 period, the number of these patients was below the average of previous years. CONCLUSION: This year's seasonal cluster of upper respiratory tract infections is associated with a higher-than-average incidence of orbital complications and mastoiditis.

Glial cell changes in the corpus callosum in chronically-starved mice.

Anorexia nervosa (AN) is characterized by emaciation, hyperactivity, and amenorrhea. Imaging studies in AN patients have revealed reductions in grey and white matter volume, which correlate with the severity of neuropsychological deficits. However, the cellular basis for the observed brain atrophy is poorly understood. Although distinct hypothalamic centers, including the arcuate nucleus (ARC) are critically involved in regulating feeding behavior, little is known about potential hypothalamic modifications in this disorder. Since glia e.g. astrocytes and microglia influence neuronal circuits, we investigated the glial changes underlying pathophysiology of starvation in the corpus callosum (CC) and hypothalamus. Female mice were given a limited amount of food once a day and had unlimited access to a running wheel until a 20% weight reduction was achieved (acute starvation). This weight reduction was maintained for two weeks to mimic chronic starvation. Immunohistochemistry was used to quantify the density of astrocytes, microglia, oligodendrocytes, and the staining intensity of neuropeptide Y (NPY), a potent orexigenic peptide. Chronic starvation induced a decreased density of OLIG2+ oligodendrocytes, GFAP+ astrocytes, and IBA1+ microglia in the CC. However, the densities of glial cells remained unchanged in the ARC following starvation. Additionally, the staining intensity of NPY increased after both acute and chronic starvation, indicating an increased orexigenic signaling. Chronic starvation induced glial cell changes in the CC in a mouse model of AN suggesting that glia pathophysiology may play a role in the disease.

The eating disorder anorexia nervosa (AN) leads to extreme body weight loss, increased physical activity, and the absence of menstrual periods. Studies have revealed reduced brain volumes in patients with AN, which are associated with the severity of cognitive impairments. The cellular basis for this brain volume loss is mostly unclear. Glial cells, recognized for their role as supporting tissue for neuronal cells, may be involved as they can influence neuronal mechanisms. Although distinct brain regions, like the hypothalamus, are critically involved in regulating feeding behavior, little is known about cell changes in that brain region of patients with AN. To investigate these changes, an animal model mimicking the symptoms of AN was used. Glial cell changes in the corpus callosum, which connects the two hemispheres of the brain, were observed. Furthermore, no glial cell changes in the arcuate nucleus of the hypothalamus were obtained. The findings indicate that glial cell changes in the corpus callosum may play a role in the disease.

HPV-associated head and neck cancer is characterized by distinct profiles of CD8+ T cells and myeloid-derived suppressor cells.

Patients with HPV--localized head and neck cancer (HNC) show inferior outcomes after surgery and radiochemotherapy compared to HPV-associated cancers. The underlying mechanisms remain elusive, but differences in immune status and immune activity may be implicated. In this study, we analyzed immune profiles of CD8+ T cells and myeloid-derived suppressor cells (MDSC) in HPV+ versus HPV- disease.The overall frequency of CD8+ T cells was reduced in HNC versus healthy donors but substantially increased after curative therapy (surgery and/or radiochemotherapy). In HPV+ patients, this increase was associated with significant induction of peripheral blood CD8+/CD45RA-/CD62L- effector memory cells. The frequency of HPV-antigen-specific CD8+ cells was low even in patients with virally associated tumors and dropped to background levels after curative therapy. Pre-therapeutic counts of circulating monocytic MDSC, but not PMN-MDSC, were increased in patients with HPV- disease. This increase was accompanied by reduced fractions of terminally differentiated CD8+ effector cells. HPV- tumors showed reduced infiltrates of CD8+ and CD45RO+ immune cells compared with HPV+ tumors. Importantly, frequencies of tumor tissue-infiltrating PMN-MDSC were increased, while percentages of Granzyme B+ and Ki-67+ CD8 T cells were reduced in patients with HPV- disease.We report differences in frequencies and relative ratios of MDSC and effector T cells in HPV- HNC compared with more immunogenic HPV-associated disease. Our data provide new insight into the immunological profiles of these two tumor entities and may be utilized for more tailored immunotherapeutic approaches in the future.

New Prognostic Score (Essen Score) to Predict Postoperative Morbidity after Resection of Lung Metastases.

BACKGROUND: Pulmonary metastasectomy (PM) is a widely accepted surgical procedure. This study aims to investigate postoperative morbidity and mortality after PM and develop a score to predict high-risk patients. METHODS: We retrospectively investigated all patients undergoing a PM in our institution from November 2012 to January 2023. Complications were defined as the diagnosis of any new disease after the PM up to 30 days after the operation. RESULTS: 1284 patients were identified. At least one complication occurred in 145 patients (11.29%). Only one patient died during the hospital stay. Preoperative cardiovascular comorbidities (OR: 2.99, 95% CI: 1.412-3.744, p = 0.01), major lung resections (OR: 2.727, 95% CI: 1.678-4.431, p < 0.01), repeated pulmonary metastasectomy (OR: 1.759, 95% CI: 1.040-2.976, p = 0.03) and open thoracotomy (OR: 0.621, 95% CI: 0.415-0.930, p = 0.02) were identified as independent factors for postoperative complications. Based on the above independent factors for postoperative morbidity, the Essen score was developed (overall correct classification: 94.6%, ROC-Analysis: 0.828, 95% CI: 0.795-0.903). CONCLUSION: PM is a safe surgical procedure with acceptable morbidity and low mortality. The aim of the Essen score is to identify patients that are associated with risk for postoperative complications after PM.

Nonfunctional TGF-ß/ALK1/ENG signaling pathway supports neutrophil proangiogenic activity in hereditary hemorrhagic telangiectasia.

The transforming growth factor ß (TGF-ß)/ALK1/ENG signaling pathway maintains quiescent state of endothelial cells, but at the same time, it regulates neutrophil functions. Importantly, mutations of this pathway lead to a rare autosomal disorder called hereditary hemorrhagic telangiectasia (HHT), characterized with abnormal blood vessel formation (angiogenesis). As neutrophils are potent regulators of angiogenesis, we investigated how disturbed TGF-ß/ALK1/ENG signaling influences angiogenic properties of these cells in HHT. We could show for the first time that not only endothelial cells, but also neutrophils isolated from such patients are ENG/ALK1 deficient. This deficiency obviously stimulates proangiogenic switch of such neutrophils. Elevated proangiogenic activity of HHT neutrophils is mediated by the increased spontaneous degranulation of gelatinase granules, resulting in high release of matrix-degrading matrix metalloproteinase 9 (MMP9). In agreement, therapeutic disturbance of this process using Src tyrosine kinase inhibitors impaired proangiogenic capacity of such neutrophils. Similarly, inhibition of MMP9 activity resulted in significant impairment of neutrophil-mediated angiogenesis. All in all, deficiency in TGF-ß/ALK1/ENG signaling in HHT neutrophils results in their proangiogenic activation and disease progression. Therapeutic strategies targeting neutrophil degranulation and MMP9 release and activity may serve as a potential therapeutic option for HHT.

Establishment of a Murine Chronic Anorexia Nervosa Model.

Anorexia nervosa (AN) is associated with hyperactivity, amenorrhea, and brain atrophy. The underlying pathophysiology is mostly unknown, and new targets for therapeutic interventions are needed. This study aimed to systematically establish a murine AN model with the parameter extent of starvation, animal age, and length of starvation for functional studies. The activity-based anorexia (ABA) model combines food restriction with running wheel access. Early adolescent and adolescent mice received 40% of their baseline food intake until a 20% or 25% weight reduction was reached (acute starvation). To mimic chronic starvation, body weight loss was maintained for another two weeks. Running activity was examined using wheel sensors, while amenorrhea was investigated by analysis of vaginal smears. Brain sections were used to analyze cerebral cortex volumes. Acute starvation did not lead to either AN-related symptoms, whereas chronic starvation led to hyperactivity and amenorrhea except in the adolescent cohort with 20% weight reduction. Only ABA mice with 25% weight reduction revealed a cortex volume reduction. The optimal parameters to mirror AN-related symptoms included a 25% weight reduction, early adolescent or adolescent mice, and chronic starvation. The ABA model enables functional analysis of the impact of chronic AN on the underlying hormonal, behavioral, and brain pathophysiology.

[Recommendations of the German Society of Otorhinolaryngology, Head and Neck Surgery (DGHNO-KHC) for the granting of resident training program authorizations]. / Empfehlungen der Deutschen Gesellschaft für HNO-Heilkunde, Kopf- und Hals-Chirurgie (DGHNO-KHC) für die Erteilung der fachspezifischen Weiterbildungsbefugnis.

The 2018 template for otorhinolaryngology specialist training of the German Medical Association is increasingly implemented by the federal associations. In this regard, the German Society recommended an otorhinolaryngology resident training plan for Otorhinolaryngology, Head and Neck Surgery (DGHNO-KHC) together with the Professional Association of German Otorhinolaryngologists as a suggested guideline for the federal medical associations. In this context, the state medical associations currently work on criteria on the basis of which otorhinolaryngologists and their training institutions can be granted authority for such a certified otorhinolaryngology resident training program.The DGHNO-KHC last made recommendations for the granting of authorizations for specialist training in otorhinolaryngology in 1999. Many contents have changed as a result of the 2018 model specialist training regulations. Therefore, a scientifically formulated proposal for the granting of continuing education authorizations is herewith provided as recommendation to the federal state medical associations.

Cognitive deficits in patients with peripheral vestibular dysfunction.

BACKGROUND AND PURPOSE: Previous studies demonstrated cognitive deficits in patients with peripheral vestibulopathy (PVP) with dysfunction of spatial navigation and orientation, but also documented cognitive decline in nonspatial abilities. This study evaluates cognitive deficits in patients with unilateral vestibulopathy (UVP) as well as bilateral vestibulopathy (BVP) in multiple cognitive domains using common screening tests to reliably detect these deficits in clinical practice. METHODS: This prospective study compared patients with UVP and BVP to age- and sex-matched healthy controls (HC). Tests included the Alzheimer's Disease Assessment Scale (ADAS), Mini-Mental Status Examination (MMSE), Trail Making Test Part A and B, Clock Drawing Task, Executive Interview-25 (EXIT25), Dementia Detection (DemTect), and the Judgment of Line Orientation (JLO). The Montgomery-Åsberg Depression Rating Scale was used to control for depression. Videonystagmography objectively reconfirmed PVP. The Vertigo Symptoms Scale and the Dizziness Handicap Inventory were used to assess for symptom severity and restrictions of activities of daily living. RESULTS: Eighty-one patients (65 UVP, 16 BVP) were compared to 55 HC. Patients showed impairment in ADAS, MMSE, DemTect, EXIT25, and JLO. No differences between UVP and BVP were detected. The relative risk (RR) estimates of developing cognitive deficits following PVP were increased. The RR for the ADAS was higher in BVP (RR = 4.91, 95% confidence interval [CI] = 1.87-12.9, p = 0.001) than in UVP (RR = 3.75, 95% CI = 1.65-8.51, p = 0.002), but was similar for the MMSE and DemTect between groups. CONCLUSIONS: Patients with PVP showed deficits in multiple cognitive domains including nonspatial cognitive abilities. Vestibulopathy could be a risk factor for the development of cognitive impairment.

SUVmax Above 20 in 18F-FDG PET/CT at Initial Diagnostic Workup Associates with Favorable Survival in Patients with Cancer of Unknown Primary.

Cancer of unknown primary (CUP) is a heterogeneous entity with a limited prognosis. Novel prognostic markers are needed for patient stratification in prospective clinical trials exploring innovative therapies. Methods: In CUP patients treated at the West German Cancer Center Essen, the prognostic value of 18F-FDG PET/CT at the initial diagnostic workup was analyzed by comparing overall survival (OS) in patients who underwent 18F-FDG PET/CT with those who did not. Results: Of 154 patients with a CUP diagnosis, 76 underwent 18F-FDG PET/CT at the initial diagnostic workup. The median overall survival (OS) of the full analysis set was 20.0 mo. Within the PET/CT subgroup, an SUVmax above 20 was associated with significantly superior OS (median OS, not reached vs. 32.0 mo; hazard ratio, 0.261; 95% CI, 0.095-0.713; P = 0.009). Conclusion: Our retrospective work shows that an SUVmax above 20 on 18F-FDG PET/CT at the initial diagnostic workup is a favorable prognostic factor in patients with CUP. This finding deserves further prospective studies for validation.

S2k Guideline - Merkel cell carcinoma (MCC, neuroendocrine carcinoma of the skin) - Update 2022.

Merkel cell carcinoma (MCC, ICD-O M8247/3) is a rare, malignant, primary skin tumor with epithelial and neuroendocrine differentiation. The tumor cells share many morphologic, immunohistochemical, and ultrastructural features with cutaneous Merkel cells. Nevertheless, the cell of origin of MCC is unclear. MCC appears clinically as a reddish to purple spherical tumor with a smooth, shiny surface and a soft to turgid, elastic consistency, usually showing rapid growth. Spontaneous and often complete regressions of the tumor are observed. These likely immunologically-mediated regressions explain the cases in which only lymph node or distant metastases are found at the time of initial diagnosis and why the tumor responds very well to immunomodulatory therapies even at advanced stages. Due to its aggressiveness, the usually given indication for sentinel lymph node biopsy, the indication of adjuvant therapies to be evaluated, as well as the complexity of the necessary diagnostics, clinical management should already be determined by an interdisciplinary tumor board at the time of initial diagnosis.

Immunological priming of mesenchymal stromal/stem cells and their extracellular vesicles augments their therapeutic benefits in experimental graft-versus-host disease via engagement of PD-1 ligands.

Mesenchymal stromal cells (MSCs) and their extracellular vesicles (EVs) exert profound anti-inflammatory and regenerative effects in inflammation and tissue damage, which makes them an attractive tool for cellular therapies. In this study we have assessed the inducible immunoregulatory properties of MSCs and their EVs upon stimulation with different combinations of cytokines. First, we found that MSCs primed with IFN-γ, TNF-α and IL-1ß, upregulate the expression of PD-1 ligands, as crucial mediators of their immunomodulatory activity. Further, primed MSCs and MSC-EVs, compared to unstimulated MSCs and MSC-EVs, had increased immunosuppressive effects on activated T cells and mediated an enhanced induction of regulatory T cells, in a PD-1 dependent manner. Importantly, EVs derived from primed MSCs reduced the clinical score and prolonged the survival of mice in a model of graft-versus-host disease. These effects could be reversed in vitro and in vivo by adding neutralizing antibodies directed against PD-L1 and PD-L2 to both, MSCs and their EVs. In conclusion, our data reveal a priming strategy that potentiates the immunoregulatory function of MSCs and their EVs. This concept also provides new opportunities to improve the clinical applicability and efficiency of cellular or EV-based therapeutic MSC products.

Assessing Medial Olivocochlear Reflex Strengths via Auditory Brainstem Response: Measurement and Variability in Normal-Hearing Individuals.

PURPOSE: Optimal measurement settings to measure the medial olivocochlear reflex (MOCR) in humans have not yet been defined. The purpose of this study was to advance the representation of the MOCR in auditory brainstem response (ABR) as an addition to the current diagnostic portfolio. PARTICIPANTS AND METHOD: Twelve female and 14 male normal-hearing adults participated in the study. Potential effects of a contralateral acoustic stimulus (CAS) on amplitude changes were investigated by recording ABR waveform profiles on the left side at click intensities of 50/60/70 dB nHL with and without CAS (60 dB SPL). Secondly, to detect potential chronological order influences, measurement settings were rearranged on the right side and measurements were repeated. Additionally, ABR thresholds were recorded with and without a CAS in 10 patients. RESULTS: When the effect of contralateral suppression was analyzed on the basis of amplitude changes, there was a change under administration of the CAS signal that was statistically significant. Interestingly, the order of recordings affected the degree of amplitude change. In three out of 10 patients, reproducible suppression effects on ABR thresholds were detectable upon CAS presentation. CONCLUSIONS: To our knowledge, this is the largest study dealing with the recording of the MOCR elicited by a contralateral noise via ABR in normal-hearing individuals. Effects of MOCR are measurable via amplitude changes upon CAS administration. Chronological orders influence the impact of this effect on amplitude changes. Optimal measurement settings have not yet been defined. However, experiments such as this study may help to further improve measurements, and thus advance the representation of the MOC reflex in ABR as an addition to the current diagnostic portfolio.

PSMA-Directed Imaging and Therapy of Salivary Gland Tumors: A Single-Center Retrospective Study.

We analyzed the diagnostic performance of prostate-specific membrane antigen (PSMA) PET/CT and the dosimetry, efficacy, and safety of 177Lu-PSMA-617 radioligand therapy (RLT) in salivary gland malignancies (SGMs). Methods: We identified 28 SGM patients with PSMA PET/CT from our database. CT and PSMA PET/CT images were evaluated separately by 3 masked readers in joint reading sessions. Pathologic findings were grouped into 6 TNM regions, and lesion-based disease extent was classified as no disease (n = 1, 4%), unifocal (n = 2, 7%), oligometastatic (n = 9, 32%), multifocal (n = 3, 11%), or disseminated (n = 13, 47%). For each region, the SUVmax of the lesion with the highest uptake was measured and the visual PSMA expression score was evaluated on a per-patient basis using PROMISE criteria. The association between PSMA expression and clinical and histopathologic markers was tested using the Student t test. Five patients underwent PSMA RLT with intratherapeutic dosimetry. Response was assessed using RECIST 1.1, and adverse events were graded according to version 5.0 of the Common Terminology Criteria for Adverse Events. Results: Compared with CT, PSMA PET/CT demonstrated additional metastatic lesions in 11 of 28 (39%) patients, leading to upstaging of TNM and lesion-based disease extent in 3 (11%) and 6 (21%) patients, respectively. PSMA PET/CT detected CT-occult local tumor, regional lymph nodes, nonregional lymph nodes, and bone metastases in 1 (4%), 4 (14%), 2 (7%), and 4 (14%) patients, respectively; no additional lesions were detected in the other predefined regions. PSMA expression level was higher than liver in 6 patients (25%). A significantly higher SUVmax was observed in male than female patients (15.8 vs. 8.5, P = 0.007) and in bone than lung lesions (14.2 vs. 6.4, P = 0.006). PSMA RLT was discontinued after 1 cycle in 3 of 5 patients because of insufficient tumor doses. No adverse events of grade 4 or higher occurred. Conclusion: In SGMs, PSMA PET/CT demonstrated a superior detection rate and led to upstaging in about one third of patients when compared with CT. The male sex and the presence of bone metastases were associated with significantly higher PSMA expression. PSMA RLT was well tolerated, but most patients did not have more than 1 cycle because of insufficient tumor doses.