Diagnostic reference levels and complexity indices in interventional radiology: a national programme.

OBJECTIVES: To propose national diagnostic reference levels (DRLs) for interventional radiology and to evaluate the impact of the procedural complexity on patient doses. METHODS: Eight interventional radiology units from Spanish hospitals were involved in this project. The participants agreed to undergo common quality control procedures for X-ray systems. Kerma area product (KAP) was collected from a sample of 1,649 procedures. A consensus document established the criteria to evaluate the complexity of seven types of procedures. DRLs were set as the 3rd quartile of KAP values. RESULTS: The KAP (3rd quartile) in Gy cm2 for the procedures included in the survey were: lower extremity arteriography (n = 784) 78; renal arteriography (n = 37) 107; transjugular hepatic biopsies (THB) (n = 30) 45; biliary drainage (BD) (n = 314) 30; uterine fibroid embolization (UFE) (n = 56) 214; colon endoprostheses (CE) (n = 31) 169; hepatic chemoembolization (HC) (n = 269) 303; femoropopliteal revascularization (FR) (n = 62) 119; and iliac stent (n = 66) 170. The complexity involved the increases in the following KAP factors from simple to complex procedures: THB x4; BD x13; UFE x3; CE x3; HC x5; FR x5 and IS x4. CONCLUSIONS: The evaluation of the procedure complexity in patient doses will allow the proper use of DRLs for the optimization of interventional radiology. KEY POINTS: • National DRLs for interventional procedures have been proposed given level of complexity • For clinical audits, the level of complexity should be taken into account. • An evaluation of the complexity levels of the procedure should be made.

Growth modification of human colon adenocarcinoma cells exposed to a low-frequency electromagnetic field.

The influence of variable low-intensity, low-frequency electromagnetic fields on culture cells is investigated. Human colon adenocarcinoma cells were exposed to a rectangular and variable magnetic field (1 and 25 Hz; 1.5 mT peak). Cultures were exposed to a dose for 15 and 360 minutes, and after 24 hours incubation, cell viability was measured with neutral red stain. The group treated for 15 minutes showed a statistically significant increase in cell growth with 1 Hz (p < 0.002) and 25 Hz (p < 0.003). In contrast, a significant decrease in cell growth was found in those cultures treated with 1 Hz for 360 minutes (p < 0.02). The effects reported could be influenced by the magnetic field frequency and the exposure time.