Impact of gonad shielding for AP pelvis on dose and image quality on different female sizes : a phantom study

Introduction In clinical practice AP pelvis standard protocols are suitable for average size patients. However, as the average body size has increased over the past decades, radiographers have had to improve their practice in order to ensure that adequate image quality with minimal radiation dose to the patient is achieved. Gonad shielding has been found to be an effective way to reduce the radiation dose to the ovaries. However, the effect of increased body size, or fat thickness, in combination with gonad shielding is unclear. The goal of the study was to investigate the impact of gonad shielding in a phantom of adult female stature with increasing fat thicknesses on SNR (as a measure for image quality) and dose for AP pelvis examination. Methods An adult Alderson female pelvis phantom was imaged with a variety of fat thickness categories as a representation of increasing BMI. 72 images were acquired using both AEC and manual exposure with and without gonad shielding. The radiation dose to the ovaries was measured using a MOSFET system. The relationship between fat thickness, SNR and dose when the AP pelvis was performed with and without shielding was investigated using the Wilcoxon signed rank test. P-values < 0.05 were considered to be statistically significant. Results Ovary dose and SNR remained constant despite the use of gonad shielding while introducing fat layers. Conclusion The ovary dose did not increase with an increase of fat thickness and the image quality was not altered. Implications for practice Based on this phantom study it can be suggested that obese patients can expect the same image quality as average patients while respecting ALARA principle when using adequate protocols

Treatment and overall survival of four types of non-metastatic periampullary cancer:nationwide population-based cohort study

Background: Periampullary adenocarcinoma consists of pancreatic adenocarcinoma (PDAC), distal cholangiocarcinoma (DC), ampullary cancer (AC), and duodenal adenocarcinoma (DA). The aim of this study was to assess treatment modalities and overall survival by tumor origin. Methods: Patients diagnosed with non-metastatic periampullary cancer in 2012–2018 were identified from the Netherlands Cancer Registry. OS was studied with Kaplan–Meier analysis and multivariable Cox regression analyses, stratified by origin. Results: Among the 8758 patients included, 68% had PDAC, 13% DC, 12% AC, and 7% DA. Resection was performed in 35% of PDAC, 56% of DC, 70% of AC, and 59% of DA. Neoadjuvant and/or adjuvant therapy was administered in 22% of PDAC, 7% of DC, 7% of AC, and 12% of DA. Three-year OS was highest for AC (37%) and DA (34%), followed by DC (21%) and PDAC (11%). Adjuvant therapy was associated with improved OS among PDAC (HR = 0.62; 95% CI 0.55–0.69) and DC (HR = 0.69; 95% CI 0.48–0.98), but not AC (HR = 0.87; 95% CI 0.62–1.22) and DA (HR = 0.85; 95% CI 0.48–1.50). Conclusion: This retrospective study identified considerable differences in treatment modalities and OS between the four periampullary cancer origins in daily clinical practice. An improved OS after adjuvant chemotherapy could not be demonstrated in patients with AC and DA

Uptake of 18 F-fluoro-2-deoxyglucose in the Healthy Testes of Young Men as Assessed by Positron Emission Tomography/Computed Tomography; Including the Inter- and Intra-observer Variation

Knowledge of the physiological testicular accumulation of 18 F-fluoro-2-deoxyglucose (FDG) is essential in order to discriminate between normal and pathological findings. In this study, the 18 F-FDG-uptake in healthy testes of young men was assessed using positron emission tomography/computed tomography (PET/CT)-scans. A total of 40 testes of 20 men with a mean age of 26.5 ± 3.9 years were evaluated. 18 F-FDG-uptake was expressed as the standardized uptake value (SUV). Testicular volume was measured on CT and PET. All scans were assessed by three researchers, one of whom assessed every scan twice. Laterality indices and inter- and intra-observer variation were evaluated. Correlation between the SUV max and SUV peak , between SUV mean and SUV peak and between age and SUV peak were assessed. Testes showed an average SUV max of 3.42 ± 0.61 , SUV peak of 3.06 ± 0.54 and SUV mean of 2.44 ± 0.44. The average testicular volume on CT was 23.0 ± 6.4 ml, whereas on PET it was 18.0 ± 5.1 ml. Laterality indices were calculated of 0.077 ± 0.065 (SUV max ), 0.074 ± 0.066 (SUV peak ), 0.072 ± 0.063 (SUV mean ), 0.245 ± 0.259 (CT), and 0.200 ± 0.188 (PET), respectively. Inter- and intra-observer reliability were found to be perfect for the SUVs (intraclass correlation coefficient [ICC] 0.992-1.0), but poor for testicular volumes (ICC 0.854-0.902). Testicular 18 F-FDG uptake in young men can be measured accurately on PET/CT and shows high symmetry. Consequently, 18 F-FDG PET/CT has the potential to become a useful instrument in the evaluation of the functioning of the individual testis

Long-term testicular position and growth of acquired undescended testis after prepubertal orchidopexy

The aim of the study was to determine long-term testicular position and growth of acquired undescended testis (UDT) after prepubertal orchidopexy. Patients who had undergone prepubertal orchidopexy for acquired UDT at our hospital between 1986 and 1999 were recruited to assess long-term testicular position and volume. Testis position was assessed by physical examination. Testis volume was measured with Prader orchidometry and ultrasound and was compared with normative values reported in the literature. A total of 105 patients (aged 14.0-31.6 years) were included with 137 acquired UDT (32 bilateral, 33 left sided, and 40 right sided). All but 1 of the orchidopexied testes (99.3%) were in low scrotal position. The mean volume of the orchidopexied testes in unilateral UDT (n = 73, 10.57 ± 3.74 mL) differed significantly from the size of the testes at the contralateral side (14.11 ± 4.23 mL) (P = .000). The operated testes (10.28 ± 3.45 mL) were smaller than the mean adult testis volume reported in the literature (13.4-13.6 mL; cutoff, 13.2 mL). Testis position after prepubertal orchidopexy for acquired UDT was nearly always low scrotal. The volume of the orchidopexied testes was smaller than both the volume of the contralateral testes and the normative values reported in the literatur

The Independent Functioning of the Orchidopexied Congenital Undescended Testis as Assessed by Positron Emission Tomography/Computed Tomography

Fertility after orchidopexied undescended testes (UDT) is impaired. Although fertility parameters are known to be more favorable in unilateral cases than in bilateral cases, the exact contribution of the unilateral orchidopexied UDT to fertility is unknown. We used testicular 18 F-fluoro-2-deoxyglucose ( 18 F-FDG)-uptake assessed by positron emission tomography/computed tomography (PET/CT) to investigate the function of the orchidopexied unilateral congenital UDT, compared to its normally descended counterpart. We hypothesize that the contribution of the orchidopexied unilateral congenital UDT to fertility in adulthood is low. Eleven men who underwent orchidopexy for congenital UDT at the age of 1.9 ± 1.4 (range, 4.5 months -4.0) years were seen in follow-up at the age of 24.1 ± 2.3 (20.6-28.0) years. All underwent physical examination, testicular ultrasonography and PET/CT. Testicular 18 F-FDG-uptake was expressed as the peak Standardized Uptake Value (SUV peak ). The mean SUV peak of the orchidopexied UDT was 2.74 ± 0.48 (2.13-3.47), which was significantly lower than its counterpart (P = 0.021). Besides, there was no correlation between the testicular volume and the SUV peak . The orchidopexied congenital UDT has been shown to be less metabolically active than its contralateral counterpart. Nevertheless, we suggest that the operated testes function to some degree