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We evaluated the potential of 18 F-fluoromethyldimethyl-2-hydroxyethyl-ammonium (FCH) PET/CT in the detection of recurrent disease or distant metastases and correlated its diagnostic accuracy with prostate-specific antigen (PSA) levels in prostate cancer patients with biochemical evidence of recurrence. Furthermore, the influences of androgen deprivation therapy (ADT) and its duration on 18 F-FCH PET were assessed in this study. Methods: This prospective study included 250 prostate cancer patients with PSA relapse who underwent 18 F-FCH PET/CT. At the time of 18 F-FCH PET/CT imaging, the mean PSA level was 46.9 6 314.7 ng/mL and 55.2% (138/250) of patients were receiving ADT. Overall, ADT was performed on 67.2% (168/250) of patients after initial treatment. Imaging was performed on an integrated PET/CT system. Acquisition started 1 min after intravenous injection of 18 F-FCH (4.07 MBq/kg of body weight) with dynamic PET images in the pelvic region during 8 min (1 min/frame) followed by a static semi-wholebody acquisition. The final diagnosis of positive PET lesions was based on histopathology or a consensus of clinical findings, additional imaging, or follow-up imaging modalities. Results: 18 F-FCH PET/CT was able to correctly detect malignant lesions in 74% (185/250) of patients but was negative in 26% (65/250). In 28% of patients, only 1 lesion was detected (69/250); from these, 65.2% (45 patients) had a local recurrence, 18.8% (13 patients) a single lymph node, and 15.9% (11 patients) a solitary bone metastasis. The sensitivity of the 18 F-FCH PET was significantly higher (P 5 0.001) in patients with ongoing ADT (85%; confidence interval, 80%-91%) than in patients without ADT (59.5%; confidence interval, 50%-69%). 18 F-FCH PET sensitivity was 77.5%, 80.7%, 85.2%, and 92.8% for the trigger PSA levels of more than 0.5, 1.0, 2.0, and 4.0 ng/mL, respectively. Scan sensitivity was 33% in patients with a trigger PSA level of less than 0.3 ng/mL and 77% in patients with a trigger PSA level of greater than 0.3 ng/mL, respectively (P 5 0.001). Using a binary logistic regression analysis model, we showed trigger PSA and ADT to be the only significant predictors of positive PET findings. Conclusion:18 F-FCH PET/CT proved its potential as a noninvasive 1-stop diagnostic modality enabling us to correctly detect occult disease in 74% of patients and to differentiate localized from systemic disease. In patients with biochemical recurrence, it also guides to an optimal treatment approach after initial treatment. Trigger PSA and ADT are the 2 significant predictors of 18 F-FCH-positive PET lesions. ADT seems not to impair 18 F-FCH uptake in hormone-refractory prostate cancer patients.

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Background: Nuclear medicine investigations are essential diagnostic tools in paediatric urology. Child-orientated examination techniques and the avoidance of sedation or anaesthesia vary in different institutions. We aimed at evaluating child friendly measures in our department to identify the potential for improvement. Based on these data, we changed the standards regarding the sedation policy and consequently re-evaluated sedation rates. Methods: Four-hundred thirty-five consecutive investigations were evaluated regarding the need for sedation, outcome and patient satisfaction at our department. After the revision of our department standards, we re-evaluated 159 examinations. Statistical analysis was performed with JUMBO (Java-supported Münsterian biometrical platform). Results: Eighty-six percent (60/70) would agree to perform an investigation under identical conditions again. Seventy-seven percent (17/22) of eligible patients >5 years of age felt good during the investigation. By changing our sedation policy, we could reduce the sedation rate from 27.1% to 7.5% (p < 0.0001; OR 0.219 95% CI 0.111–0.423). Conclusion: The evaluation of child friendly examination protocols demonstrated high reliability and patient satisfaction using situational sedation with a relatively high proportion of patients being sedated. Through protocol adaption with clear age limits, individual indication and education of staff, as well as the use of optimized sedatives, the need for sedation could be further reduced whilst maintaining a high patient satisfaction.

Aim: 11C-and 18F-choline PET/CT have been established as a promising modality in the assessment of prostate cancer patients1. However, it suffers to detect small malignant lesions. 68Ga-PSMA (PSMA) PET/CT showed promising in the detection of small lesions with a high tumor to background contrast2. This study was designed for comparison of detection rate between PSMA and 18F-fluoromethylcholine (FCH) PET/CT scan in pre or postop prostate cancer patients. Methods: In this prospective study 15 consecutive prostate cancer patients (mean age 67.9, range 57-83) underwent both PSMA and FCH PET/CT with a maximum interval of 4 weeks without any treatment in between. The imaging modalities were performed in 9 patients (mean age: 70.3; range: 63-83) in pre-and 6 Patients (mean age: 64.2; range: 57-71) in post-operative setting. Prostate cancer patients with histopathologic verification or biochemical recurrence were included in this study. Patients with systemic therapy and known second cancer were excluded. Pathologic findings in each imaging modalities have to be clarified histopathologically or by conventional imaging modalities and/or clinical follow-up. Results: Staging: The mean of PSA was 35.1 ng/ml (range: 3.44 -81.17 ng/ml). Pathologically increased tracer uptake was detected on both imaging modalities in the prostate gland in all patients [mean size on PSMA PET/CT: 20 mm (range: 12-43); FCH PET/CT: 23.6 mm (range: 12-34) & mean SUVmax on PSMA PET/CT: 16.2 (range: 6.1-28.1); FCH PET/CT: 7.4 (range: 3.6-15.9)]. Overall, a total number of 15 and 14 positive lymph nodes were detected on PSMA PET/CT and FCH PET/CT images, respectively. Malignant lymph nodes showed significantly higher uptake on PSMA-comparing FCH PET/CT [mean SUVmax on PSMA PET/CT: 12.8 (range: 2.8-34); FCH PET/CT: 6.6 (range: 2.3-11.9)]. However, there was no appreciable difference in the tracer intensity of the detected bony lesions in each modality. Restaging: The mean of PSA was 2.3 ng/ml (range: 0.48 -5.35). Local recurrence with pathologically increased tracer uptake was detected in one patient on both imaging modalities, However, it shows markedly higher uptake on PSMA PET/CT (SUVmax: PSMA: 12.4; FCH: 4.9). In addition, PSMA PET/CT was able to detect higher number of metastatic lymph nodes compared with FCH PET/CT (14 vs. 10) with significantly better tumor to background ratio (SUVmax 8.7 on PSMA vs 4.45 on FCH).One false positive bone lesion was detected on PSMA PET/CT study. Although the MRI was negative, follow-up imaging was planned within 4-6 months. Also, two false positive bone lesions were detected on FCH PET/CT images in bilateral femurs. Moreover, PSMA PET/CT was false negative in one bony lesion detected by FCH PET/CT. Conclusion: PSMA PET/CT reveals a more promising role for staging and re-staging of prostate cancer patients even with low PSA level. Markedly higher tumor to background contrast is seen on PSMA PET/ CT which allows higher detection rate especially in the small lesions. However, the value of this modality in the assess...

Background Bone stock preservation in total hip replacement is essential to allow for later revisions in an increasingly younger and fitter index patient population. While contemporary modular press-fit acetabular cups lead to rigid fixation with equatorial stress and central osteolysis, more elastic fixation may cause different peri-acetabular bone remodelling. The purpose of this study was to investigate changes in peri-acetabular bone mineral density (BMD) in uncemented elastic fixation with monoblock press-fit cups. Methods This prospective observational study included 45 patients with monoblock cups. We evaluated peri-acetabular BMD using dual-energy X-ray absorptiometry and reported functional outcomes and complications. Results At a mean follow-up of 24.2 ± 2.2 months, we found that BMD stabilised in DeLee and Charnley zones I and III and recovered to baseline value in zone II. The mean Harris Hip Scores improved significantly from 56.9 ± 20.0 to 97.2 ± 4.0 (p <  0001). Other than one peri-operative dislocation, we saw no post-operative complications. Conclusions We found favourable adaptive bone changes with BMD stabilisation in the equatorial zones and recovery to pre-operative values in the central zone. Additionally, excellent clinical outcomes and few prosthesis-related complications strengthened the favourable results of monoblock acetabular cups. Trial registration Registration number DRKS00017076.

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