Aim of the study was to evaluate the diagnostic performance and feasibility of transabdominal ultrasound shear wave elastography (SWE) in assessing sonoelastographic features of the uterus. Twenty-seven premenopausal women were enrolled between 2021 and 2022. Transabdominal SWE measured myometrial stiffness in various uterine segments. Additionally, tissue stiffness of the quadriceps femoris muscle and autochthonous back muscle was measured. Statistical analysis employed non-parametric tests, t test, and a robust mixed linear model. Stiffness values of the uterus and the two investigated muscle types exhibited a similar spectrum: 6.38 ± 2.59 kPa (median 5.61 kPa; range 2.76–11.31 kPa) for the uterine myometrium, 7.22 ± 1.24 kPa (6.82 kPa; 5.11–9.39 kPa) for the quadriceps femoris musle, and 7.43 ± 2.73 kPa (7.41 kPa; 3.10–13.73 kPa) for the autochthonous back muscle. A tendency for significant differences in myometrial stiffness was observed concerning the type of labor mode (mean stiffness of 9.17 ± 1.35 kPa after vaginal birth vs. 3.83 ± 1.35 kPa after Caesarian section, p = 0.01). No significant differences in myometrial stiffness were observed concerning age, BMI, previous pregnancies, uterine flexion and menstrual cycle phase. Transabdominal SWE of uterine stiffness seems to be a fast and practicable method in a clinical setting. Uterine stiffness appears to be largely independent of various factors, except for the mode of delivery. However, further studies are needed to validate these results.

Background: Pancreatic adenocarcinoma (PaC) still has a dismal prognosis, and despite medical advances, a bleak 5-year survival rate of only 8%, largely due to late diagnosis and limited curative surgical options for most patients. Frontline palliative treatment shows some survival advantages. However, the high disease mortality is accompanied by high morbidity including cancer-related pain and additional symptoms, which strongly impair patients’ quality of life (QOL). At present, there is no established strategy for local therapy for PaC primarily aiming to manage local tumor growth and alleviate associated symptoms, particularly pain. In recent years, non-invasive high-intensity focused ultrasound (HIFU) has shown promising results in reducing cancer pain and tumor mass, improving patients’ QOL with few side effects. Study design: This is the first randomized controlled trial worldwide including 40 patients with inoperable pancreatic adenocarcinoma randomized into two groups: group A undergoing standard chemotherapy; and group B undergoing standard chemotherapy plus local HIFU treatment. This study aims to establish a robust evidence base by examining the feasibility, safety, and efficacy of US-guided HIFU in combination with standard palliative systemic therapy for unresectable PaC. Primary endpoint assessments will focus on parameters including safety issues (phase I), and local response rates (phase II).

The aim of this study is to assess the clinical outcome and mid-term efficacy of ultrasound-guided high-intensity focused ultrasound (USgHIFU) as a treatment for symptomatic uterine fibroids at two major European HIFU centers. This bi-center longitudinal clinical study involved the treatment of 100 patients with symptomatic uterine fibroids using USgHIFU (n = 59 in Germany, n = 41 in Bulgaria). Clinical outcomes were evaluated at 6 weeks, 6 months, and 1 year follow-up utilizing the uterine fibroid symptoms-quality of life questionnaire for fibroid-related symptoms and health-related quality of life as well as MRI imaging for determining the fibroid volume. The mean fibroid volume reduction rate was 33.2 ± 22.9

Uterine fibroids are the most common benign tumors of the uterus. Approximately 20–50% of women with myomas experience a variety of symptoms such as vaginal bleeding, abdominal pain, pelvic pain and pressure, and urological problems, possibly interfering with fertility and pregnancy. Although surgery remains the standard treatment option for fibroids, non-invasive therapeutic options, such as high-intensity focused ultrasound (HIFU), have emerged over the last dec ade. During HIFU, ultrasound is focused on the target tissue causing coagulation necrosis. HIFU has, meanwhile, become an established method for treating uterine fibroids in many countries. Clinical data have shown that it effectively alleviates fibroid-related symptoms and reduces fibroid size with a very low rate of side effects. However, there is a lack of data on how this treatment affects laboratory parameters and structural features of uterine tissue. As our center is the only one in German-speaking countries where ultrasound-guided HIFU technology is currently established, the aim of this prospective, monocentric, single-arm trial is not only to evaluate the safety and efficacy of local US-guided HIFU in symptomatic uterine fibroid patients according to GCP standards but also to explore its effects on blood parameters and the structural integrity of uterine tissue using elastographic methods.

Purpose: Ultrasound-guided high-intensity focused ultrasound (USgHIFU) represents a safe and effective non-invasive thermoablative technique for managing inoperable pancreatic cancer. This treatment method significantly alleviates disease-related symptoms and reduces pancreatic tumor volume. However, the current body of evidence is constrained by a lack of randomized controlled trials. The utilization of USgHIFU is primarily indicated for patients with unresectable, locally advanced, or metastatic pancreatic cancer, particularly those experiencing symptoms due to a locally advanced primary tumor.Methods: This collaborative consensus paper, involving European and Chinese HIFU centers treating pancreatic cancer, delineates criteria for patient selection, focusing on those most likely to benefit from USgHIFU treatment. Consideration is given to endpoints encompassing symptom alleviation, local response rates, other oncological outcomes, as well as overall and progression-free survival. Additionally, this paper defines relevant contraindications, side effects, and complications associated with USgHIFU. The publication also explores the feasibility and role of USgHIFU within the context of palliative care, including standard systemic chemotherapy.Results: The non-invasive local treatment of advanced pancreatic cancer using HIFU should be regarded as an adjunctive option alongside systemic chemotherapy or best supportive care for managing this aggressive disease. Based on the ability of USgHIFU therapy to mitigate pain and reduce primary tumor volume, it should be considered as a complementary therapy for symptomatic patients with inoperable pancreatic cancer and as a potential means of tumor debulking. The underutilized yet promising USgHIFU exhibits the potential to enhance patients' quality of life by alleviating cancer-related pain. Experts in the field should evaluate this treatment option be evaluated by experts in this field, with this consensus paper potentially serving as a guiding resource for the medical community.Conclusions: US-guided HIFU for advanced pancreatic cancer addresses treatment goals, available options, success rates, and limitations. As a non-invasive, effective local therapy, complementary to chemotherapy and best supportive care, it plays a pivotal role in pain relief, reducing of tumor volume, and potentially improving survival rates.

Purpose: The most important prognostic factor for survival in ovarian cancer patients is complete cytoreduction. The preoperative prediction of suboptimal cytoreduction, considered as any residual disease at the end of surgery, could prevent futile surgery and morbidity. Here, we aimed to identify markers in the preoperative abdominal CT scans of an unselected cohort of patients with ovarian cancer that are predictive of incomplete cytoreduction. Methods: This is a single-institution retrospective analysis of 105 epithelial ovarian cancer (EOC) patients treated with surgical cytoreduction between 2010 and 2020. Twenty-two variables on preoperative abdominal CT scans were compared to the intraoperative macroscopic findings by Fisher's exact test. Parameters with a significant correlation between intraoperative findings and imaging were analyzed by multivariate binary logistic regression analysis regarding the surgical outcome of complete versus incomplete cytoreduction. Results: Complete cytoreduction (CC), indicated by the absence of macroscopic residual disease, was achieved in 79 (75.2%) of 105 patients and 46 (63.9%) of 72 International Federation of Gynecology and Obstetrics (FIGO) stage III and IV patients. Twenty patients (19%) were incompletely cytoreduced due to miliary carcinomatosis of the small bowel, and six patients (5.7%) had various locations of residual disease. Thirteen variables showed a significant correlation between imaging and surgical findings. Large-volume ascites, absence of numerically increased small lymph nodes at the mesenteric root, and carcinomatosis of the transverse colon in FIGO stage III and IV patients decreased the rate of CC to 26.7% in the multivariate analysis. Conclusion: Large-volume ascites, the absence of numerically increased small lymph nodes at the mesenteric root, and carcinomatosis of the transverse colon are markers in preoperative CT scans predicting a low chance for complete cytoreduction in unselected ovarian cancer patients in a real-world setting.

Uterine fibroids are the most common benign uterine tumors and can cause various severe symptoms as abnormal menstrual bleeding or pelvic pain. Therefore, the primary objective in the treatment of uterine fibroids is a sufficient symptom relief. Ultrasound (US)-guided High-intensity focused ultrasound (HIFU) is an effective non-invasive treatment strategy for ablation of uterine fibroids that can achieve a significant tumor volume reduction. The aim of the study is to evaluate if US-guided HIFU treatment can reduce fibroid-associated symptoms leading to an improvement of health-related quality of life. Fifty-five women with symptomatic uterine fibroids underwent US-guided HIFU ablation. Clinical evaluation was performed on the basis of the Uterine Fibroid Symptom and Health-Related Quality of Life Questionnaire (UFS-QOL) at baseline, 6 weeks, 3, 6, 9 and 12 months after HIFU. Imaging follow-up included contrast-enhanced ultrasound (CEUS) and contrast-enhanced MRI. A significant reduction of the Symptom Severity Scale (SSS) was observed between 6 weeks and 12 months after HIFU (49.9 ± 19.4 at baseline vs. 42.2 ± 20.1 at 6 weeks and 23.6 ± 12.7 at 12 months after treatment, p < 0.001) correlating with a significant improvement ( p < 0.001) of Health-related Quality of Life (HRQL) (52.5 ± 22.7 at baseline vs. 59.8 ± 22 at 6 weeks and 77.9 ± 17.3 at 12 months after treatment). Significant postinterventional improvement was observed in every subscale of HRQL. In the majority of patients, only minor, short-lasting and self-limiting side effects were observed, e.g. soft tissue edema of the anterior lower abdominal wall in the acoustic pathway or transient moderate lower abdominal pain as during menstruation. One patient with a very large fibroid experienced strong short-lasting pain after the procedure; two patients experienced post-procedurally a transient sciatic nerve irritation. US-guided HIFU of uterine fibroids reduces disease-related symptoms and improves health-related quality of life.

OBJECTIVES:Pancreatic cancer patients often have a high symptom burden, significantly impairing patients' quality of life (QOL). Nevertheless, there are hardly any reports on the impact of high-intensity focused ultrasound (HIFU) on the QOL of treated patients. For the first time, this study evaluated the effect of HIFU on QOL and compared these results in two European centers.METHODS:Eighty patients with advanced pancreatic cancer underwent HIFU (50 in Germany, 30 in Bulgaria). Clinical assessment included evaluation of QOL and symptoms using the EORTC QLQ-C30 questionnaire at baseline and 1, 3, and 6 months after HIFU. Pain intensity was additionally evaluated with the numerical rating score (NRS).RESULTS:Compared to baseline, global health significantly improved 3 and 6 months after HIFU treatment (p = 0.02). Functional subscales including physical, emotional, and social functioning were considerably improved at 6 months (p = 0.02, p = 0.01, and p = 0.01, respectively) as were leading symptom pain (p = 0.04 at 6 months), fatigue (p = 0.03 at 3 and p = 0.01 at 6 months), and appetite loss (p = 0.01 at 6 months). Moreover, pain intensity measured by NRS revealed effective and strong pain relief at all time points (p < 0.001). Reported effects were independent of tumor stage, metastatic status, and country of treatment.CONCLUSIONS:This study showed that HIFU represents an effective treatment option of advanced pancreatic cancer improving QOL by increasing global health and mitigation of physical complaints with a low rate of side effects, independent of the examiner. Therefore, HIFU is a worthwhile additional treatment besides systemic palliative chemotherapy or best supportive care in management of this aggressive disease.KEY POINTS:• In a prospective two-center study, it was shown that HIFU represents an effective treatment option of advanced pancreatic cancer improving QOL. • HIFU in pancreatic cancer patients is associated with a low rate of side effects, independent of the performer. • HIFU is a worthwhile additional treatment besides systemic palliative chemotherapy or best supportive care in management of this aggressive disease.

Introduction High-intensity focused ultrasound (HIFU) is an innovative noninvasive procedure for local ablation of different benign and malignant tumors. Preliminary data of animal studies suggest an ablation-associated immune response after HIFU that is induced by cell necrosis and release of intracellular components. The aim of this study is to evaluate if a HIFU-induced early sterile inflammatory reaction is initiated after ablation of uterine fibroids (UF) and pancreatic carcinoma (PaC) which might contribute to the therapeutic effect.Material and methods A hundred patients with PaC and 30 patients with UF underwent US-guided HIFU treatment. Serum markers of inflammation (leukocytes, CRP, IL-6) and LDH in both collectives as well as tumor markers CA 19-9, CEA and CYFRA in PaC patients were determined in sub-cohorts before and directly after HIFU (0, 2, 5 and 20 h post-ablation) as well as at 3, 6, 9 and 12 months follow-up. Peri-/post interventional imaging included contrast-enhanced MRI of both cohorts and an additional CT scan of PaC patients.Results An early post-ablation inflammatory response was observed in both groups with a significant increase of leukocytes, CRP and LDH within the first 20 h after HIFU. Interestingly, IL-6 was increased at 20 h after HIFU in PaC patients. A significant reduction of tumor volumes was observed during one year follow-up (p < .001) for both tumor entities demonstrating effective treatment outcome.Conclusion Tumor ablation with HIFU induces an early sterile inflammation that might serve as a precondition for long-term tumor immunity and a sustainable therapeutic effect.

Little is known about the specific anaesthesiological and multidisciplinary management of high-intensity focused ultrasound (HIFU) in uterine fibroids. This observational single-center study is the first reporting on an interdisciplinary approach to optimize outcome following ultrasound (US)-guided HIFU in German-speaking countries. A sample of forty patients with symptomatic uterine fibroids was treated by HIFU. Relevant treatment parameters such as total treatment time for intervention, anaesthesia, and sonication time as well as total energy, body temperature, peri-interventional medication and complications were analyzed. Interventional variables did not correlate significantly either with opioid dose or with body temperature. The average fibroid volume reduction rate was 37.8% ± 23.5%, 48.5% ± 22.0% and 70.2% ± 25.5% after 3, 6 and 12 months, respectively. No major anaesthesiological complications occurred apart from an epileptic seizure prior to HIFU treatment in one patient. Peri-procedural hyperthermia (> 37.5 °C) occurred in two patients. Post-procedural two patients experienced a sciatic nerve irritation up to one year; one patient with very large treated fibroid experienced strong short-lasting post-procedural pain. There were two complication-free pregnancies of HIFU-treated patients. Multidisciplinary management is crucial to optimize safety and outcome of US-guided HIFU for uterine fibroids. Peri-procedural pain and temperature management are critical points where an adequate collaboration between anesthesiologist and interventionalist is mandatory.

Introduction To evaluate treatment response of uterine fibroids after ultrasound guided high-intensity focused ultrasound (USgHIFU) with a special focus on fibroid size and characterization based on Funaki classification scheme, as well as clinical response to treatment of leading fibroid-associated symptoms. Materials and methods Uterine fibroids treated by USgHIFU were assigned to Funaki type 1-3 based on T2-w-MRI. Differences in size, non-perfused volume ratio (NPVR) and volume reduction over time were determined using T1-/T2-w MRI sequences and contrast-enhanced sonography. Treatment effects on three leading fibroid-associated symptoms were also evaluated. Measurements were compared by mixed model, Bland-Altman's plot and Spearman's correlation. Results In this prospective single-center study, 35 patients with 44 symptomatic uterine fibroids were treated by USgHIFU (n = 22, n = 12 and n = 10 assigned to Funaki type 1, 2 and 3, respectively). NPVRs of Funaki type 1 and 2 fibroids were significantly higher compared to type 3 (p = .0023). A significant fibroid shrinkage was observed independent of Funaki type compared to baseline: 38.8 +/- 26.9%, 46.7 +/- 30.3% and 54.5 +/- 29.3% at 3, 6 and 12 months, respectively (each p < .05). Moreover, patients experienced a significant improvement of fibroid-associated hypermenorrhea (3.9 +/- 1.3 vs. 2.3 +/- 1.3), pressure in the pelvic area (3.5 +/- 1.3 vs. 2.1 +/- 0.9) and frequent urination (2.8 +/- 1.5 vs. 1.9 +/- 0.8) one year post-procedure (each p < .05), regardless of fibroid Funaki type. Conclusion Following USgHIFU, a significant shrinkage of uterine fibroids and improvement of leading fibroid-associated symptoms were demonstrated regardless of the Funaki type.

Introduction High-intensity focused ultrasound (HIFU) for pancreatic cancer is a growing therapeutic field which has been proven to reduce cancer pain and provide a local tumor control additionally to standard palliative care. However, less is known about the multidisciplinary and especially anesthesiological management of HIFU treatment although an interdisciplinary approach is crucial for treatment success. Material and methods Anesthesiological and radiological records of 71 HIFU-treated pancreatic cancer patients were analyzed with regard to the following items: intervention time, sonication time, total energy, anesthesia time, peri-interventional medication, body temperature maximum and minimum, pain scores before and 1 day, 6 weeks and 3 months after intervention, peri-interventional complications. Effects on pain scores were estimated with a mixed panel data model. Bivariate associations between interventional variables were examined with the Spearman’s correlation. Results HIFU treatment was performed without major adverse events. Peri-procedural hyperthermia >37.5 °C occurred in 2 patients, hypothermia <35 °C in 8 cases. Interventional variables did not correlate significantly with pain scores, opioid dose, nor body temperature. 85.5% of patients experienced significant early pain relief within the first week after intervention. Post-interventional pain relief is associated with morphine equivalent opioid dose (p = 0.025) and treatment time (p = 0.040). Conclusion While HIFU can be considered safe and effective treatment option, procedure-associated pain and temperature management represent challenges for the interdisciplinary HIFU intervention team. Especially short-term pain relief depends on the combined effort of the radiologist and anesthesiologist.

Abstract Purpose Pancreatic cancer (PaC) is a life-limiting tumor with a wide range of incapacitating symptoms such as cancer pain in more than 80 % of patients. This prospective interventional study addresses the clinical effectiveness of ultrasound-guided high-intensity focused ultrasound (HIFU) treatment for patients with advanced-stage PaC, including pain perception, tumor size and survival benefit. Materials and Methods 50 patients with late-stage PaC underwent HIFU. Clinical assessment included evaluation of tumor volume by imaging and pain burden (pain severity, pain sensation, interference with daily activities) using the Brief Pain Inventory at baseline and follow-up. Median overall survival, progression-free survival and time to local progression were estimated using Kaplan-Meier analysis. Results In 84 % of patients, significant early relief of cancer-induced abdominal pain was achieved by HIFU independent of metastatic status; it persisted during follow-up. Tumor volume reduction was 37.8 ± 18.1 % after 6 weeks and 57.9 ± 25.9 % after 6 months. 21 % of HIFU-treated patients had local tumor progression with a median time of 14.4 months from intervention. The median overall survival and progression-free survival were 16.2 and 16.9 months from diagnosis and 8.3 and 6.8 months from intervention. Conclusion In patients with advanced pancreatic cancer and otherwise limited treatment options, HIFU resulted in significant early and long-lasting pain relief and tumor size reduction over time independent of metastatic status. Clinical data suggest an additional potential survival benefit.

We read with interest the article by Dr. Bojunga in Ultraschall in der Medizin entitled “Ultrasound for Thyroid Nodules” [1]. This is a well-written and clearly structured education article. However, there is one statement that needs clarification. On pages 490 and 491, the author explains that “echogenicity is subdivided into hyperechoic, isoechoic, hypoechoic as well as distinctly hypoechoic, in each case related to the striated neck muscles”. In our opinion, this is not correct and only applies for the distinction of (moderate) hypoechoic (for example TIRADS 4) to distinctly hypoechoic (for example TIRADS 5) lesions [2]. In the captions, for example for figure 2, the author even clearly compares the echogenicity of the isoechoic nodule to the surrounding thyroid parenchyma and not to the neck muscles.

Zusammenfassung Hintergrund Das lokal fortgeschrittene Pankreaskarzinom ist ein lebenslimitierender Tumor mit einer Vielzahl von Symptomen, u. a. Tumorschmerz. Lokal ablative Verfahren, die thermische oder auch nichtthermische Techniken anwenden, können als moderne Therapieoptionen zur Tumorkontrolle und symptomatischen Verbesserung eingesetzt werden. Dieser Artikel gibt einen Überblick über die derzeit verfügbaren Behandlungsverfahren und -ergebnisse, einschließlich unserer eigenen Erfahrungen mit dem hoch-intensiven fokussierten Ultraschall (HIFU). Methode Unsere Erfahrungen mit der HIFU-Therapie beim Pankreaskarzinom basieren auf 89 Patienten (UICC III-IV). Neben den HIFU-Ergebnissen wurden Ergebnisse zur lokalen Tumorkontrolle, Sicherheit sowie Mortalität und behandlungsabhängigen Veränderung von Symptomen aus publizierten Studien zur Radiofrequenz-, Mikrowellen- und Kryoablation, irreversiblen Elektroporation und stereotaktischen Strahlentherapie einbezogen. Ergebnisse Obwohl die unterschiedlichen Modalitäten überwiegend sicher durchführbar sind, bietet der HIFU mit seiner Nicht-Invasivität einen entscheidenden methodischen Vorteil. Mit HIFU konnte bei 85% der Patienten eine effektive und lang anhaltende Schmerzlinderung erreicht werden; bei 50% war nach 6 Wochen keinerlei analgetische Medikation erforderlich. Leider sind Schmerzlinderung und Lebensqualität bei den anderen lokalen Behandlungsmethoden nur selten untersucht. Eine Tumormassenreduktion konnte mit allen ablativen Therapien erreicht werden, wobei diese 6 Monate nach HIFU im Mittel bei 60% lag. Unterschiede in der behandlungsassoziierten Morbidität wurden berichtet, sind jedoch aufgrund der unausgewogenen Studienpopulationen nur eingeschränkt vergleichbar. Schlussfolgerung Eine Vielzahl an lokal ablativen Behandlungsmodalitäten sind zur Tumormassenreduktion beim fortgeschrittenen Pankreaskarzinom verfügbar, bieten aber unterschiedlichen symptomatischen Nutzen. Eine effektive und lang anhaltende Reduktion von Tumorschmerzen ohne Einführen von Nadeln oder Elektroden in den Tumorbereich bietet ausschließlich das HIFU-Verfahren. Randomisierte, kontrollierte klinische Studien zum direkten Vergleich der hier vorgestellten Modalitäten sind in der näheren Zukunft zu befürworten.

Mit Interesse haben wir den Artikel der Arbeitsgruppe um die Professoren Maintz und Güll gelesen, die in 2 Publikationen über den magnetresonanzgesteuerten hochintensiven fokussierten Ultraschall(MRg-HIFU) berichten; im Teil 1 [1] über die technischen Aspekte und die etablierten Applikationen, in einem zweiten Artikel mit einem Überblick über neue Anwendungsgebiete [2]. Wir möchten den Autoren zuerst zu diesem gelungenen Überblick gratulieren.

Background Locally advanced pancreatic cancer is a life-limiting tumor with a wide range of incapacitating symptoms such as cancer-associated pain. Several local ablative therapies with both thermal and non-thermal sources have recently received significant attention as modern treatment options for local tumor control and symptomatic improvement. The following review article provides an overview of currently available techniques and their outcomes including our own experience with high-intensity focused ultrasound (HIFU) being one of the most exciting and innovative modalities. Method Our experiences with HIFU treatment are based on 89 pancreatic cancer patients (UICC III-IV). Outcomes such as treatment-related changes in symptoms particularly in cancer pain and quality of life as well as local tumor response, safety and survival were compared to reported studies concerning HIFU, radiofrequency and microwave ablation, cryoablation, irreversible electroporation and stereotactic body radiation therapy. Results Even though all strategies appeared to be feasible, the unique feature of noninvasiveness represents a substantial advantage of the HIFU procedure. In 85 % of HIFU-treated patients, long-lasting pain relief was achieved. 50 % of patients did not require any analgesic treatment 6 weeks post-ablation. Unfortunately, pain palliation and quality-of-life outcomes are only rarely reported for other local treatment modalities. Tumor mass reduction could be achieved with all ablative therapies, with a mean tumor volume reduction of 60 % after 6 months in HIFU-treated pancreatic tumors. Differences in treatment-associated morbidity were reported. However, they are only partially comparable due to unbalanced study populations. Conclusion Various local ablative treatment modalities are available and feasible for tumor mass reduction of advanced pancreatic cancer but with different symptomatic benefit for patients. An effective and long-lasting reduction of cancer-related pain was observed following HIFU without insertion of needles or electrodes. Randomized controlled studies for head-to-head comparison of these modalities are warranted in the near future.

Periprosthetic loosening, either aseptic or induced by periprosthetic joint infection remains a major long term complication and challenge in orthopedics and trauma surgery. Sensitivity of potential loosening of the material and other causes of a painful prosthesis is essential for choosing the respective treatment option and providing the needed resources. 18F-Fluoride is a radiopharmaceutical which shows a high affinity to bone and a rapid blood clearance. The objective of this study was to assess 18F-Fluoride PET/CT´s sensitivity and specificity in diagnosing periprosthetic loosening in total hip and knee arthroplasty. We included 26 patients with 24 hip and 13 knee prostheses in our retrospective study with radiological or clinical suspicion of peri-prosthetic loosening at least one year after implantation. Results of 18F-Fluoride PET/CT imaging were compared with surgical results or clinical follow-up if surgery was not performed. On the basis of our data we found a sensitivity of 95.00 %, a specificity of 87.04 % and an accuracy of 89.19 % for 18F-Fluoride PET/CT. The results of our study show that 18F-Fluoride PET/CT is a useful and promising technique in diagnosing periprosthetic loosening of total hip and knee arthroplasties. Further investigation should focus on different uptake patterns of the isotope in periprosthetic joint infection and therefore distinguishing aseptic from septic loosening and enhancing the diagnostic value of this imaging method.