Impact of pulmonary embolism on morbidity and mortality in patients undergoing pancreatic surgery.

PURPOSE: Postoperative pulmonary embolism (PE) after pancreatic surgery is a potentially life-threatening complication. However, the magnitude of morbidity and mortality of PE is still uncertain. The present study aims to assess the incidence of PE after pancreatic surgery and analyze its impact on the outcome. METHODS: We conducted a retrospective study including all patients who underwent pancreatic resections between 2005 and 2017. The development of PE was analyzed for a 90-day period following surgery. Risk factors were evaluated using regression models. RESULTS: The study investigated 947 patients undergoing pancreatic surgery. Overall, 26 (2.7%) patients developed PE. The median body mass index (BMI) of patients with PE was significantly higher (28.1 kg/m2 [24.7-31.8] vs. 24.8 kg/m2 [22.4-27.8], p < 0.001). Patients with PE had a significantly increased duration of the operation and more often underwent multivisceral resections. The lowest incidence of PE was found after distal or total pancreatectomy (2%). In median, PE occurred on the fifth postoperative day (interquartile range: 3-9). Increased BMI, duration of operation, and postoperative deep venous thrombosis were found to be multivariate risk factors for the development of PE. Importantly, postoperative complications (53.8% vs. 15.1%, p < 0.001) and the 30-day mortality rate were significantly increased in the PE group (19.2% vs. 3.3%, p < 0.001). CONCLUSIONS: Patients with increased BMI, a history of deep venous thrombosis, and multivisceral resections are a high-risk group for PE after pancreatic surgery. While the absolute incidence and related mortality of PE after pancreatic surgery is low, it is associated with severe sequelae.

DOSIMETRY WITH THE ABILITY TO DISTINGUISH PULSED AND NON-PULSED DOSE CONTRIBUTIONS.

The concept of an active dosimetry system for pulsed radiation dose rate measurements is presented. Real-time distinction of pulsed and non-pulsed radiation contributions is based on the time structure of a single interaction. A fast tissue equivalent plastic scintillator is exploited to minimize the pile-up effect influence on absorbed energy measurements. Being connected to a fully digital signal processing board, the detector creates an active dosimetry system with adjustable parameters. With this system, absorbed dose rate measurements were carried out in a photon field with a time structure mimicking a radiotherapeutic beam, but also in the presence of a constant radiation field. Measurements show a linear dependence of a pulsed radiation contribution on the accelerator current in the investigated range of the total dose rate up to 8 µGy h-1. While increasing the accelerator current by 1 µA, the pulsed radiation dose rate grows by (26.2 ± 0.9) nGy h-1 when considering pile-up events.

Drain Amylase or Lipase for the Detection of POPF-Adding Evidence to an Ongoing Discussion.

： Objectives: A postoperative pancreatic fistula (POPF) is defined as a threefold increase in the amylase concentration in abdominal drains on or after the third postoperative day (POD). However, additional lipase fluid analysis is widely used despite lacking evidence. In this study, drain amylase and lipase levels were compared regarding their value in detecting POPF. Methods: We conducted a retrospective study including all patients who underwent pancreatic resections at our center between 2005 and 2016. Drain fluid analysis was performed from day 2 to 5. Results: 990 patients were included in the analysis. Overall, 333 (34%) patients developed a POPF. The median amylase and lipase concentrations at POD 3 in cases with POPF were 11.55 µmol/(s·L) (≈13 ×-fold increase) and 39 µmol/(s·L) (≈39 ×-fold increase), respectively. Seven patients with subsequent POPF (2%) were missed with amylase analysis on POD 3, but detected using 3-fold lipase analysis. The false-positive rate of lipase was 51/424 = 12%. A cutoff lipase value at POD 3 of > 4.88 yielded a specificity of 94% and a sensitivity of 89% for development of a POPF. Increased body mass index turned out as risk factor for the development of POPF in a multivariable model. Conclusions: Threefold-elevated lipase concentration may be used as an indicator of a POPF. However, the additional detection of POPF using simultaneous lipase analysis is marginal. Therefore, assessment of lipase concentration does not provide added clinical value and only results in extra costs.

Scintillation properties of the YVO4:Eu3+ compound in powder form: its application to dosimetry in radiation fields produced by pulsed mega-voltage photon beams.

The investigation of scintillation properties of europium doped yttrium orthovanadate shows the suitability of this material for fiber-based dose rate measurements. All measurements were carried out with a 6 MV Varian linear accelerator. The temperature dependence of the signal is lower than that of the plastic scintillators reported so far. By measuring the afterglow of probes between Linac-pulses, the signal due to the stem effect can be successfully eliminated. Comparison of depth dose profiles in a water phantom for radiation field dimensions between 1 x 1 cm(2) and 10 x 10 cm(2) shows that the probes are suitable for small fields having dimensions up to 1 x 1 cm(2). The high light yield of probes having dimensions of 1 mm opens up the possibility for their use in spatially confined radiation fields, such as in intensity-modulated radiotherapy (IMRT) and volume-modulated radiation therapy (VMAT).

Dose reduction in computed tomography: the effect of eye and testicle shielding on radiation dose measured in patients with beryllium oxide-based optically stimulated luminescence dosimetry.

The aim of this study was to assess the effect of eye and testicle shielding on radiation dose to the lens and the testes of patients undergoing CT examinations. Fifty-one male patients underwent CT twice with identical protocols initially without, the second time with protective garments. Doses to the testes and the lenses were recorded with beryllium oxide-based dosimeters. The dose to the testes and lenses from CT exposure was reduced by 96.2% +/- 1.7% and 28.2% +/- 18.5%, when testicle and eye shielding was used, respectively. The effect of the eye shielding on the eye lens dose was found to depend on the x-ray tube position when the eye is primarily exposed during the scan. The maximum eye lens dose reduction achieved was found to be 43.2% +/- 6.5% corresponding to the anterior position of the tube. A significant correlation between the patient's body mass index and dose exposure could not be found. Eye and testicle shields, apart from being inexpensive and easy to use, were proven to be effective in reducing eye lens and testicle radiation dose burden from CT exposures.